chamilo-lms2/main/survey/survey.lib.php

<?php
/* For licensing terms, see /license.txt */
/**
 * Survey manager class
 *
 * @package chamilo.survey
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University: cleanup, refactoring and rewriting large parts (if not all) of the code
 * @author Julio Montoya Armas <gugli100@gmail.com>, Chamilo: Personality Test modification and rewriting large parts of the code
 * @version $Id: survey.lib.php 22296 2009-07-22 22:05:50Z cfasanando $
 * @todo move this file to inc/lib
 * @todo use consistent naming for the functions (save vs store for instance)
 */
/**
 * Code
 */
$config['survey']['debug'] = false;

$htmlHeadXtra[] = '<script>
function setFocus(){
    $("#search_title").focus();
}
$(document).ready(function () {
    setFocus();
});
</script>';

class survey_manager
{

    /**
     * Deletes all survey invitations of a user
     * @param int $user_id
     * @return boolean
     * @assert ('') === false
     */
    public static function delete_all_survey_invitations_by_user($user_id)
    {
        $user_id = intval($user_id);

        if (empty($user_id)) {
            return false;
        }
        $table_survey_invitation = Database :: get_course_table(TABLE_SURVEY_INVITATION);
        $table_survey = Database :: get_course_table(TABLE_SURVEY);

        $sql = "SELECT survey_invitation_id, survey_code
                FROM $table_survey_invitation WHERE user = '$user_id' AND c_id <> 0 ";
        $result = Database::query($sql);
        $deleted = array();
       	while ($row = Database::fetch_array($result ,'ASSOC')){
            $survey_invitation_id = $row['survey_invitation_id'];
            $survey_code = $row['survey_code'];
            $sql2 = "DELETE FROM $table_survey_invitation WHERE survey_invitation_id = '$survey_invitation_id' AND c_id <> 0";
            if (Database::query($sql2)) {
                $sql3 = "UPDATE $table_survey SET invited = invited-1 ".
                       " WHERE c_id  <> 0 AND code ='$survey_code'";
                Database::query($sql3);
            }
        }
    }

    /**
     *
     * @param type $course_code
     * @param type $session_id
     * @return type
     * @assert ('') === false
     */
    public static function get_surveys($course_code, $session_id = 0)
    {
        $table_survey = Database :: get_course_table(TABLE_SURVEY);
        if (empty($course_code)) {
            return false;
        }
        $course_info = api_get_course_info($course_code);
        $session_condition = api_get_session_condition($session_id, true, true);

        $sql = "SELECT * FROM $table_survey WHERE c_id = {$course_info['real_id']} $session_condition ";
        $result = Database::query($sql);
        $result = Database::store_result($result, 'ASSOC');
        return $result;
    }

	/**
	 * Retrieves all the survey information
	 *
	 * @param integer $survey_id the id of the survey
	 * @param boolean $shared this parameter determines if
     * we have to get the information of a survey from the central (shared) database or from the
	 * 		  course database
	 * @param string course code optional
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
     * @assert ('') === false
	 *
	 * @todo this is the same function as in create_new_survey.php
	 */
    public static function get_survey($survey_id, $shared = 0, $course_code = '')
    {
		// Table definition
		if (!empty($course_code)) {
			$my_course_id = $course_code;
		} else if (isset($_GET['course'])) {
			$my_course_id = Security::remove_XSS($_GET['course']);
		} else {
			$my_course_id = api_get_course_id();
		}
		$my_course_info = api_get_course_info($my_course_id);
		$table_survey = Database :: get_course_table(TABLE_SURVEY);

		if ($shared != 0) {
			$table_survey	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION);
            $sql = "SELECT * FROM $table_survey WHERE survey_id='".Database::escape_string($survey_id)."' ";
		} else {
		    $sql = "SELECT * FROM $table_survey WHERE survey_id='".Database::escape_string($survey_id)."' AND c_id = ".$my_course_info['real_id'];
		}

		$result = Database::query($sql);
		$return = array();

		if (Database::num_rows($result)> 0) {
			$return = Database::fetch_array($result,'ASSOC');
			// We do this (temporarily) to have the array match the quickform elements immediately
			// idealiter the fields in the db match the quickform fields
			$return['survey_code'] 			= $return['code'];
			$return['survey_title'] 		= $return['title'];
			$return['survey_subtitle'] 		= $return['subtitle'];
			$return['survey_language'] 		= $return['lang'];
			$return['start_date'] 			= $return['avail_from'];
			$return['end_date'] 			= $return['avail_till'];
			$return['survey_share'] 		= $return['is_shared'];
			$return['survey_introduction'] 	= $return['intro'];
			$return['survey_thanks'] 		= $return['surveythanks'];
			$return['survey_type'] 		    = $return['survey_type'];
			$return['one_question_per_page']= $return['one_question_per_page'];
			$return['show_form_profile']	= $return['show_form_profile'];
			$return['input_name_list']		= isset($return['input_name_list']) ? $return['input_name_list'] : null;
			$return['shuffle']				= $return['shuffle'];
			$return['parent_id']			= $return['parent_id'];
			$return['survey_version']		= $return['survey_version'];
        }
        return $return;
	}

	/**
	 * This function stores a survey in the database.
	 *
	 * @param array $values
	 * @return array $return the type of return message that has to be displayed and the message in it
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
    public static function store_survey($values)
    {
        $_user = api_get_user_info();
        $course_id = api_get_course_int_id();
		$table_survey 	= Database :: get_course_table(TABLE_SURVEY);
		$shared_survey_id = 0;

		if (!$values['survey_id'] || !is_numeric($values['survey_id'])) {
			// Check if the code doesn't soon exists in this language
			$sql = 'SELECT 1 FROM '.$table_survey.'
			        WHERE
			            c_id = '.$course_id.' AND
			            code="'.Database::escape_string($values['survey_code']).'" AND
			            lang="'.Database::escape_string($values['survey_language']).'"';
			$rs = Database::query($sql);
			if (Database::num_rows($rs) > 0) {
				$return['message'] = 'ThisSurveyCodeSoonExistsInThisLanguage';
				$return['type'] = 'error';
				$return['id'] = isset($values['survey_id']) ? $values['survey_id'] : 0;
				return $return;
			}

			if ($values['anonymous'] == '') {
				$values['anonymous'] = 0;
			}

			$additional['columns'] = '';
			$additional['values'] = '';

			if ($values['anonymous'] == 0) {
				// Input_name_list
				$additional['columns'] .= ', show_form_profile';
				$additional['values'] .= ",'".Database::escape_string($values['show_form_profile'])."'";

				if ($values['show_form_profile'] == 1) {
					// Input_name_list
					$fields = explode(',', $values['input_name_list']);
					$field_values = '';
					foreach ($fields as & $field) {
						if ($field != '') {
							if ($values[$field] == '') {
								$values[$field] = 0;
							}
							$field_values.= $field.':'.$values[$field].'@';
						}
					}
					$additional['columns'] .= ', form_fields';
					$additional['values'] .= ",'".Database::escape_string($field_values)."'";
				} else {
					$additional['columns'] .= ', form_fields';
					$additional['values'] .= ",''";
				}
			} else {
				// Input_name_list
				$additional['columns'] .= ', show_form_profile';
				$additional['values'] .= ",'0'";

				$additional['columns'] .= ', form_fields';
				$additional['values'] .= ",''";
			}

			if ($values['survey_type'] == 1) {
				$additional['columns'] .= ', survey_type';
				$additional['values'] .= ",'1'";

				$additional['columns'] .= ', shuffle';
				$additional['values'] .= ",'".Database::escape_string($values['shuffle'])."'";

				$additional['columns'] .= ', one_question_per_page';
				$additional['values'] .= ",'".Database::escape_string($values['one_question_per_page'])."'";

				$additional['columns'] .= ', parent_id';
				$additional['values'] .= ",'".Database::escape_string($values['parent_id'])."'";

				// Logic for versioning surveys
				if (!empty($values['parent_id'])) {
					$additional['columns'] .= ', survey_version';
					$sql = 'SELECT survey_version FROM '.$table_survey.' WHERE c_id = '.$course_id.' AND parent_id = '.Database::escape_string($values['parent_id']).' ORDER BY survey_version DESC LIMIT 1';
					$rs = Database::query($sql);
					if (Database::num_rows($rs) === 0) {
						$sql = 'SELECT survey_version FROM '.$table_survey.' WHERE  c_id = '.$course_id.' survey_id = '.Database::escape_string($values['parent_id']);
						$rs = Database::query($sql);
						$getversion = Database::fetch_array($rs, 'ASSOC');
						if (empty($getversion['survey_version'])) {
							$additional['values'] .= ",'".++$getversion['survey_version']."'";
						} else {
							$additional['values'] .= ",'".$getversion['survey_version'].".1'";
						}
					} else {
						$row = Database::fetch_array($rs, 'ASSOC');
						$pos = api_strpos($row['survey_version']);
						if ($pos === false) {
							//$new_version = substr($row['survey_version'],$pos, count())
							$row['survey_version'] = $row['survey_version'] + 1;
							$additional['values'] .= ",'".$row['survey_version']."'";
						} else {
							$getlast = explode('\.', $row['survey_version']);
							$lastversion = array_pop($getlast);
							$lastversion = $lastversion + 1;
							$add = implode('.', $getlast);
							if ($add != '') {
								$insertnewversion = $add.'.'.$lastversion;
							} else {
								$insertnewversion = $lastversion;
							}
							$additional['values'] .= ",'".$insertnewversion."'";
						}
					}
				}
			}
			$course_id = api_get_course_int_id();
			$sql = "INSERT INTO $table_survey (c_id, code, title, subtitle, author, lang, avail_from, avail_till, is_shared, template, intro, surveythanks, creation_date, anonymous".$additional['columns'].", session_id) VALUES (
						$course_id,
						'".Database::escape_string(strtolower(generate_course_code(api_substr($values['survey_code'],0))))."',
						'".Database::escape_string($values['survey_title'])."',
						'".Database::escape_string($values['survey_subtitle'])."',
						'".Database::escape_string($_user['user_id'])."',
						'".Database::escape_string($values['survey_language'])."',
						'".Database::escape_string($values['start_date'])."',
						'".Database::escape_string($values['end_date'])."',
						'".Database::escape_string($shared_survey_id)."',
						'".Database::escape_string('template')."',
						'".Database::escape_string($values['survey_introduction'])."',
						'".Database::escape_string($values['survey_thanks'])."',
						'".date('Y-m-d H:i:s')."',
						'".Database::escape_string($values['anonymous'])."'".$additional['values'].",
						".api_get_session_id()."
						)";
			Database::query($sql);
			$survey_id = Database::insert_id();
			if ($survey_id > 0) {
				// Insert into item_property
				api_item_property_update(api_get_course_info(), TOOL_SURVEY, $survey_id, 'SurveyAdded', api_get_user_id());
			}

			if ($values['survey_type'] == 1 && !empty($values['parent_id'])) {
				survey_manager::copy_survey($values['parent_id'],$survey_id);
			}

			$return['message'] = 'SurveyCreatedSuccesfully';
			$return['type'] = 'confirmation';
			$return['id'] = $survey_id;

		} else {

			// Check whether the code doesn't soon exists in this language
			$sql = 'SELECT 1 FROM '.$table_survey.'
			        WHERE c_id = '.$course_id.' AND code="'.Database::escape_string($values['survey_code']).'" AND lang="'.Database::escape_string($values['survey_language']).'" AND survey_id!='.intval($values['survey_id']);
			$rs = Database::query($sql);
			if (Database::num_rows($rs) > 0) {
				$return['message'] = 'ThisSurveyCodeSoonExistsInThisLanguage';
				$return['type'] = 'error';
				$return['id'] = isset($values['survey_id']) ? $values['survey_id'] : 0;
				return $return;
			}

			if ($values['anonymous'] == '') {
				$values['anonymous'] = 0;
			}

			$additionalsets = ", shuffle = '".Database::escape_string($values['shuffle'])."'";
			$additionalsets .= ", one_question_per_page = '".Database::escape_string($values['one_question_per_page'])."'";

			if ($values['anonymous'] == 0) {
				$additionalsets .= ", show_form_profile = '".Database::escape_string($values['show_form_profile'])."'";
				if ($values['show_form_profile'] == 1) {
					$fields = explode(',',$values['input_name_list']);
					$field_values = '';
					foreach ($fields as & $field) {
						if ($field != '') {
							if ($values[$field] == '') {
								$values[$field] = 0;
							}
							$field_values.= $field.':'.$values[$field].'@';
						}
					}
					$additionalsets .= ", form_fields = '".Database::escape_string($field_values)."'";
				} else {
					$additionalsets .= ", form_fields = '' ";
				}
			} else {
				$additionalsets .= ", show_form_profile = '0'";
				$additionalsets .= ", form_fields = '' ";
			}

			$sql = "UPDATE $table_survey SET
                        title 			= '".Database::escape_string($values['survey_title'])."',
                        subtitle 		= '".Database::escape_string($values['survey_subtitle'])."',
                        author 			= '".Database::escape_string($_user['user_id'])."',
                        lang 			= '".Database::escape_string($values['survey_language'])."',
                        avail_from 		= '".Database::escape_string($values['start_date'])."',
                        avail_till		= '".Database::escape_string($values['end_date'])."',
                        is_shared		= '".Database::escape_string($shared_survey_id)."',
                        template 		= '".Database::escape_string('template')."',
                        intro			= '".Database::escape_string($values['survey_introduction'])."',
                        surveythanks	= '".Database::escape_string($values['survey_thanks'])."',
                        anonymous       = '".Database::escape_string($values['anonymous'])."'".$additionalsets."
					WHERE c_id = $course_id AND survey_id = '".Database::escape_string($values['survey_id'])."'";
			Database::query($sql);

			// Update into item_property (update)
			api_item_property_update(api_get_course_info(), TOOL_SURVEY, $values['survey_id'], 'SurveyUpdated', api_get_user_id());

			$return['message'] = 'SurveyUpdatedSuccesfully';
			$return['type'] = 'confirmation';
			$return['id']	= $values['survey_id'];
		}
		return $return;
	}

	/**
	 * This function stores a shared survey in the central database.
	 *
	 * @param array $values
	 * @return array $return the type of return message that has to be displayed and the message in it
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
    public function store_shared_survey($values)
    {
        $_user = api_get_user_info();
        $_course = api_get_course_info();

		// Table defnitions
		$table_survey	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY);

		if (!$values['survey_id'] || !is_numeric($values['survey_id']) || $values['survey_share']['survey_share'] == 'true') {
			$sql = "INSERT INTO $table_survey (code, title, subtitle, author, lang, template, intro, surveythanks, creation_date, course_code) VALUES (
						'".Database::escape_string($values['survey_code'])."',
						'".Database::escape_string($values['survey_title'])."',
						'".Database::escape_string($values['survey_subtitle'])."',
						'".Database::escape_string($_user['user_id'])."',
						'".Database::escape_string($values['survey_language'])."',
						'".Database::escape_string('template')."',
						'".Database::escape_string($values['survey_introduction'])."',
						'".Database::escape_string($values['survey_thanks'])."',
						'".date('Y-m-d H:i:s')."',
						'".$_course['id']."')";
			Database::query($sql);
			$return	= Database::insert_id();
		} else {
			$sql = "UPDATE $table_survey SET
                        code 			= '".Database::escape_string($values['survey_code'])."',
                        title 			= '".Database::escape_string($values['survey_title'])."',
                        subtitle 		= '".Database::escape_string($values['survey_subtitle'])."',
                        author 			= '".Database::escape_string($_user['user_id'])."',
                        lang 			= '".Database::escape_string($values['survey_language'])."',
                        template 		= '".Database::escape_string('template')."',
                        intro			= '".Database::escape_string($values['survey_introduction'])."',
                        surveythanks	= '".Database::escape_string($values['survey_thanks'])."'
					WHERE survey_id = '".Database::escape_string($values['survey_share']['survey_share'])."'";
			Database::query($sql);
			$return	= $values['survey_share']['survey_share'];
		}
		return $return;
	}

	/**
	 * This function deletes a survey (and also all the question in that survey
	 *
	 * @param $survey_id the id of the survey that has to be deleted
	 * @return true
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
    public static function delete_survey($survey_id, $shared = false, $course_id = '') {
		// Database table definitions
        if (empty($course_id)) {
            $course_id = api_get_course_int_id();
        }

        $survey_id = intval($survey_id);

        if (empty($survey_id)) {
            return false;
        }

		$course_info = api_get_course_info_by_id($course_id);
		$course_id   = $course_info['real_id'];

		$table_survey = Database :: get_course_table(TABLE_SURVEY);
		$table_survey_question_group = Database :: get_course_table(TABLE_SURVEY_QUESTION_GROUP);

		if ($shared) {
			$table_survey = Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY);
			 // Deleting the survey
            $sql = "DELETE FROM $table_survey WHERE survey_id='".$survey_id."'";
            Database::query($sql);
		} else {
		    $sql = "DELETE FROM $table_survey WHERE c_id = $course_id AND survey_id='".$survey_id."'";
            Database::query($sql);
		}

		// Deleting groups of this survey
		$sql = "DELETE FROM $table_survey_question_group WHERE c_id = $course_id AND survey_id='".$survey_id."'";
		Database::query($sql);

		// Deleting the questions of the survey
		survey_manager::delete_all_survey_questions($survey_id, $shared);

		// Update into item_property (delete)
		api_item_property_update($course_info, TOOL_SURVEY, $survey_id, 'SurveyDeleted', api_get_user_id());
		return true;
	}

    /**
     * @param int $parent_survey
     * @param int $new_survey_id
     * @return bool
     */
    public function copy_survey($parent_survey, $new_survey_id)
    {
	    $course_id = api_get_course_int_id();

		// Database table definitions
		$table_survey 					= Database::get_course_table(TABLE_SURVEY);
		$table_survey_question_group 	= Database::get_course_table(TABLE_SURVEY_QUESTION_GROUP);
		$table_survey_question 			= Database::get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_options 			= Database::get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$parent_survey 					= Database::escape_string($parent_survey);
		// Get groups
		$sql = "SELECT * from $table_survey_question_group WHERE c_id = $course_id AND  survey_id='".$parent_survey."'";
		$res = Database::query($sql);
		if (Database::num_rows($res) === 0) {
			return true;
		}
		$new_survey_id = intval($new_survey_id);
		while($row = Database::fetch_array($res, 'ASSOC')){
			$sql1 = 'INSERT INTO '.$table_survey_question_group.' (c_id, name,description,survey_id) VALUES
					('.$course_id.', \''.Database::escape_string($row['name']).'\',\''.Database::escape_string($row['description']).'\',\''.$new_survey_id.'\')';
			Database::query($sql1);
			$group_id[$row['id']] = Database::insert_id();
		}

		// Get questions
		$sql = "SELECT * FROM $table_survey_question WHERE c_id = $course_id AND survey_id='".$parent_survey."'";
		$res = Database::query($sql);
		while($row = Database::fetch_array($res, 'ASSOC')){
			$sql2 = 'INSERT INTO '.$table_survey_question.' (c_id, survey_id,survey_question,survey_question_comment,type,display,sort,shared_question_id,max_value,survey_group_pri,survey_group_sec1,survey_group_sec2) VALUES '.
			'('.$course_id.', \''.$new_survey_id.'\',\''.Database::escape_string($row['survey_question']).'\',\''.Database::escape_string($row['survey_comment']).'\',\''.$row['type'].'\',\''.$row['display'].'\',\''.$row['sort'].'\',\''.$row['shared_question_id'].'\',\''.$row['max_value'].
			'\',\''.$group_id[$row['survey_group_pri']].'\',\''.$group_id[$row['survey_group_sec1']].'\',\''.$group_id[$row['survey_group_sec2']].'\')';
			Database::query($sql2);
			$question_id[$row['question_id']] = Database::insert_id();
		}

		// Get questions options
		$sql = "SELECT * FROM $table_survey_options WHERE c_id = $course_id AND survey_id='".$parent_survey."'";
		$res = Database::query($sql);
		while($row = Database::fetch_array($res ,'ASSOC')){
			$sql3 = 'INSERT INTO '.$table_survey_options.' (c_id, question_id,survey_id,option_text,sort,value) VALUES ('.
			" $course_id ,    '".$question_id[$row['question_id']]."','".$new_survey_id."','".Database::escape_string($row['option_text'])."','".$row['sort']."','".$row['value']."')";
			Database::query($sql3);
		}

		return true;
	}

	/**
	 * This function duplicates a survey (and also all the question in that survey
	 *
	 * @param $survey_id the id of the survey that has to be duplicated
	 * @return true
	 *
	 * @author Eric Marguin <e.marguin@elixir-interactive.com>, Elixir Interactive
	 * @version October 2007
	 */
    public function empty_survey($survey_id)
    {
		// Database table definitions
		$table_survey_invitation      = Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_survey_answer          = Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$table_survey                 = Database :: get_course_table(TABLE_SURVEY);

        $course_id = api_get_course_int_id();

		$datas = survey_manager::get_survey($survey_id);
		$session_where = '';
		if (api_get_session_id() != 0) {
			$session_where = ' AND session_id = "'.api_get_session_id().'" ';
		}

		$sql = 'DELETE FROM '.$table_survey_invitation.' WHERE c_id = '.$course_id.' AND survey_code = "'.Database::escape_string($datas['code']).'" '.$session_where.' ';
		Database::query($sql);

		$sql = 'DELETE FROM '.$table_survey_answer.' WHERE c_id = '.$course_id.' AND survey_id='.intval($survey_id);
		Database::query($sql);

		$sql = 'UPDATE '.$table_survey.' SET invited=0, answered=0 WHERE c_id = '.$course_id.' AND survey_id='.intval($survey_id);
		Database::query($sql);

		return true;
	}

	/**
	 * This function recalculates the number of people who have taken the survey (=filled at least one question)
	 *
	 * @param int $survey_id the id of the survey somebody
	 * @return true
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
    public static function update_survey_answered($survey_data, $user, $survey_code)
    {
		// Database table definitions
		$table_survey 				= Database :: get_course_table(TABLE_SURVEY);
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);

        $survey_id = $survey_data['survey_id'];
        $course_id = $survey_data['c_id'];
        $session_id = $survey_data['session_id'];

		// Getting a list with all the people who have filled the survey
		$people_filled = survey_manager::get_people_who_filled_survey($survey_id, false, $course_id);

		$number = intval(count($people_filled));

		// Storing this value in the survey table
		$sql = "UPDATE $table_survey
		        SET answered = $number
		        WHERE
                    c_id = $course_id AND
		            survey_id = ".Database::escape_string($survey_id);
		Database::query($sql);

		// Storing that the user has finished the survey.
		$sql = "UPDATE $table_survey_invitation SET answered='1'
                WHERE
                    c_id = $course_id AND
                    session_id='".$session_id."' AND
                    user='".Database::escape_string($user)."' AND
                    survey_code='".Database::escape_string($survey_code)."'";
		Database::query($sql);
	}

	/**
	 * This function gets a complete structure of a survey (all survey information, all question information
	 * of all the questions and all the options of all the questions.
	 *
	 * @param integer $survey_id the id of the survey
	 * @param boolean $shared this parameter determines if we have to get the information of a survey from the central (shared) database or from the
	 * 		  course database
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
    public static function get_complete_survey_structure($survey_id, $shared = 0)
    {
		$structure = survey_manager::get_survey($survey_id, $shared);
		$structure['questions'] = survey_manager::get_questions($survey_id);
	}

	/***
	 * SURVEY QUESTION FUNCTIONS
	 */

	/**
	 * This function return the "icon" of the question type
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
    public static function icon_question($type)
    {
		// the possible question types
		$possible_types = array('personality', 'yesno', 'multiplechoice', 'multipleresponse', 'open', 'dropdown', 'comment', 'pagebreak', 'percentage', 'score');

		// the images array
		$icon_question = array(
			'yesno' 			=> 'yesno.gif',
			'personality' 		=> 'yesno.gif',
			'multiplechoice' 	=> 'mcua.gif',
			'multipleresponse' 	=> 'mcma.gif',
			'open' 				=> 'open_answer.gif',
			'dropdown' 			=> 'dropdown.gif',
			'percentage' 		=> 'percentagequestion.gif',
			'score' 			=> 'scorequestion.gif',
			'comment' 			=> 'commentquestion.gif',
			'pagebreak' 		=> 'page_end.gif',
		);

		if (in_array($type, $possible_types)) {
			return $icon_question[$type];
		} else {
			return false;
		}
	}

	/**
	 * This function retrieves all the information of a question
	 *
	 * @param integer $question_id the id of the question
	 * @return array
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @todo one sql call should do the trick
	 */
    public static function get_question($question_id, $shared = false)
    {
		// Table definitions
		$tbl_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
        $course_id = api_get_course_int_id();

        $sql = "SELECT * FROM $tbl_survey_question
                WHERE c_id = $course_id AND question_id='".Database::escape_string($question_id)."' ORDER BY `sort` ";
        $sql_survey_question_option = "SELECT * FROM $table_survey_question_option WHERE c_id = $course_id AND question_id='".Database::escape_string($question_id)."' ORDER BY `sort` ";
		if ($shared) {
			$tbl_survey_question 			= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION);
			$table_survey_question_option	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION_OPTION);

            $sql = "SELECT * FROM $tbl_survey_question WHERE question_id='".Database::escape_string($question_id)."' ORDER BY `sort` ";
            $sql_survey_question_option = "SELECT * FROM $table_survey_question_option WHERE question_id='".Database::escape_string($question_id)."' ORDER BY `sort` ";
		}

		// Getting the information of the question

		$result = Database::query($sql);
		$row = Database::fetch_array($result,'ASSOC');
		$return['survey_id'] 			= $row['survey_id'];
		$return['question_id'] 			= $row['question_id'];
		$return['type'] 				= $row['type'];
		$return['question'] 			= $row['survey_question'];
		$return['horizontalvertical'] 	= $row['display'];
		$return['shared_question_id']	= $row['shared_question_id'];
		$return['maximum_score']		= $row['max_value'];

  		if ($row['survey_group_pri'] != 0) {
  			$return['assigned'] = $row['survey_group_pri'];
	 		$return['choose'] = 1;
   		} else {
 	 		$return['assigned1'] = $row['survey_group_sec1'];
  			$return['assigned2'] = $row['survey_group_sec2'];
	 		$return['choose'] = 2;
  		}

		// Getting the information of the question options

		$result = Database::query($sql_survey_question_option);
		while ($row = Database::fetch_array($result, 'ASSOC')) {
			/** @todo this should be renamed to options instead of answers */
			$return['answers'][] = $row['option_text'];
			$return['values'][] = $row['value'];

			/** @todo this can be done more elegantly (used in reporting) */
			$return['answersid'][] = $row['question_option_id'];
		}

		return $return;
	}

	/**
	 * This function gets all the question of any given survey
	 *
	 * @param integer $survey_id the id of the survey
	 * @return array containing all the questions of the survey
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 *
	 * @todo one sql call should do the trick
	 */
    public static function get_questions($survey_id, $course_id = '')
    {
		// Table definitions
		$tbl_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);

		if (empty($course_id))
		{
			$course_id = api_get_course_int_id();
		}

		// Getting the information of the question
		$sql = "SELECT * FROM $tbl_survey_question
		        WHERE c_id = $course_id AND survey_id='".Database::escape_string($survey_id)."'";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result, 'ASSOC')) {
			$return[$row['question_id']]['survey_id'] 			= $row['survey_id'];
			$return[$row['question_id']]['question_id'] 		= $row['question_id'];
			$return[$row['question_id']]['type'] 				= $row['type'];
			$return[$row['question_id']]['question'] 			= $row['survey_question'];
			$return[$row['question_id']]['horizontalvertical'] 	= $row['display'];
			$return[$row['question_id']]['maximum_score'] 		= $row['max_value'];
			$return[$row['question_id']]['sort'] 				= $row['sort'];
		}

		// Getting the information of the question options
		$sql = "SELECT * FROM $table_survey_question_option
		        WHERE c_id = $course_id AND survey_id='".Database::escape_string($survey_id)."'";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result, 'ASSOC')) {
			$return[$row['question_id']]['answers'][] = $row['option_text'];
		}

		return $return;
	}

	/**
	 * This function saves a question in the database.
	 * This can be either an update of an existing survey or storing a new survey
	 *
	 * @param array $form_content all the information of the form
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
    public function save_question($survey_data, $form_content)
    {
		if (strlen($form_content['question']) > 1) { // Checks lenght of the question
			$empty_answer = false;

			if ($survey_data['survey_type'] == 1) {
				if (empty($form_content['choose'])) {
					$return_message = 'PleaseChooseACondition';
					return $return_message;
				}

				if (($form_content['choose']==2)&&($form_content['assigned1'] == $form_content['assigned2'])) {
					$return_message = 'ChooseDifferentCategories';
					return $return_message;
				}
			}

			if ($form_content['type'] != 'percentage') {
				for ($i = 0; $i < count($form_content['answers']); $i++) {
					if (strlen($form_content['answers'][$i]) < 1) {
						$empty_answer = true;
						break;
					}
				}
			}

			if ($form_content['type'] == 'score') {
				if (strlen($form_content['maximum_score']) < 1) {
					$empty_answer = true;
				}
			}
			$additional = array();

            $course_id = api_get_course_int_id();

			if (!$empty_answer) {
				// Table definitions
				$tbl_survey_question 	= Database :: get_course_table(TABLE_SURVEY_QUESTION);

				// Getting all the information of the survey
				$survey_data = survey_manager::get_survey($form_content['survey_id']);

				// Storing the question in the shared database
				if (is_numeric($survey_data['survey_share']) && $survey_data['survey_share'] != 0) {
					$shared_question_id = survey_manager::save_shared_question($form_content, $survey_data);
					$form_content['shared_question_id'] = $shared_question_id;
				}

				// Storing a new question
				if ($form_content['question_id'] == '' || !is_numeric($form_content['question_id'])) {
					// Finding the max sort order of the questions in the given survey
					$sql = "SELECT max(sort) AS max_sort
					        FROM $tbl_survey_question
                            WHERE c_id = $course_id AND survey_id='".Database::escape_string($form_content['survey_id'])."'";
					$result = Database::query($sql);
					$row = Database::fetch_array($result,'ASSOC');
					$max_sort = $row['max_sort'];

					// Some variables defined for survey-test type
					$additional['column'] = '';
					$additional['value'] = '';

					if ($_POST['choose'] == 1) {
						$additional['column'] = ',survey_group_pri';
						$additional['value'] = ",'".Database::escape_string($_POST['assigned'])."'";
					} elseif($_POST['choose'] == 2) {
						$additional['column'] = ',survey_group_sec1, survey_group_sec2';
						$additional['value'] = ",'".Database::escape_string($_POST['assigned1'])."'".",'".Database::escape_string($_POST['assigned2'])."'";
					}

					// Adding the question to the survey_question table
					$sql = "INSERT INTO $tbl_survey_question (c_id, survey_id,survey_question,survey_question_comment,type,display, sort, shared_question_id, max_value".$additional['column'].") VALUES (
								$course_id,
								'".Database::escape_string($form_content['survey_id'])."',
								'".Database::escape_string($form_content['question'])."',
								'".Database::escape_string($form_content['question_comment'])."',
								'".Database::escape_string($form_content['type'])."',
								'".Database::escape_string($form_content['horizontalvertical'])."',
								'".Database::escape_string($max_sort+1)."',
								'".Database::escape_string($form_content['shared_question_id'])."',
								'".Database::escape_string($form_content['maximum_score'])."'".
								$additional['value']."
								)";
					Database::query($sql);
					$question_id = Database::insert_id();
					$form_content['question_id'] = $question_id;
					$return_message = 'QuestionAdded';

				} else {
                    // Updating an existing question

					$additionalsets = '';

					if ($_POST['choose'] == 1) {
						$additionalsets = ',survey_group_pri = \''.Database::escape_string($_POST['assigned']).'\', survey_group_sec1 = \'0\', survey_group_sec2 = \'0\' ';
					}
					elseif ($_POST['choose'] == 2) {
						$additionalsets = ',survey_group_pri = \'0\', survey_group_sec1 = \''.Database::escape_string($_POST['assigned1']).'\', survey_group_sec2 = \''.Database::escape_string($_POST['assigned2']).'\' ';
					}

					$setadditionals = $additional['set'][1].$additional['set'][2].$additional['set'][3];

					// Adding the question to the survey_question table
					$sql = "UPDATE $tbl_survey_question SET
                                survey_question 		= '".Database::escape_string($form_content['question'])."',
                                survey_question_comment = '".Database::escape_string($form_content['question_comment'])."',
                                display 				= '".Database::escape_string($form_content['horizontalvertical'])."',
                                max_value 				= '".Database::escape_string($form_content['maximum_score'])."'" .
                                $additionalsets."
                            WHERE c_id = $course_id AND question_id = '".Database::escape_string($form_content['question_id'])."'";
					Database::query($sql);
					$return_message = 'QuestionUpdated';
				}

                if (!empty($form_content['survey_id'])) {
                    //Updating survey
                    api_item_property_update(api_get_course_info(), TOOL_SURVEY, $form_content['survey_id'], 'SurveyUpdated', api_get_user_id());
                }

				// Storing the options of the question
				$message_options=survey_manager::save_question_options($form_content, $survey_data);
			} else {
				$return_message = 'PleasFillAllAnswer';
			}
		} else {
			$return_message = 'PleaseEnterAQuestion';
		}
		return $return_message;
	}

	/**
	 * This function saves the question in the shared database
	 *
	 * @param array $form_content all the information of the form
	 * @param array $survey_data all the information of the survey
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 *
	 * @todo editing of a shared question
	 */
    public function save_shared_question($form_content, $survey_data)
    {
        $_course = api_get_course_info();

        // Table definitions
        $tbl_survey_question 	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION);

        // Storing a new question
        if ($form_content['shared_question_id'] == '' || !is_numeric($form_content['shared_question_id'])) {
            // Finding the max sort order of the questions in the given survey
            $sql = "SELECT max(sort) AS max_sort FROM $tbl_survey_question
                    WHERE survey_id='".Database::escape_string($survey_data['survey_share'])."'
                    AND code='".Database::escape_string($_course['id'])."'";
            $result = Database::query($sql);
            $row = Database::fetch_array($result,'ASSOC');
            $max_sort = $row['max_sort'];

            // Adding the question to the survey_question table
            $sql = "INSERT INTO $tbl_survey_question (survey_id, survey_question, survey_question_comment, type, display, sort, code) VALUES (
                        '".Database::escape_string($survey_data['survey_share'])."',
                        '".Database::escape_string($form_content['question'])."',
                        '".Database::escape_string($form_content['question_comment'])."',
                        '".Database::escape_string($form_content['type'])."',
                        '".Database::escape_string($form_content['horizontalvertical'])."',
                        '".Database::escape_string($max_sort+1)."',
                        '".Database::escape_string($_course['id'])."')";
            Database::query($sql);
            $shared_question_id = Database::insert_id();
        }  else {
            // Updating an existing question
            // adding the question to the survey_question table
            $sql = "UPDATE $tbl_survey_question SET
                        survey_question = '".Database::escape_string($form_content['question'])."',
                        survey_question_comment = '".Database::escape_string($form_content['question_comment'])."',
                        display = '".Database::escape_string($form_content['horizontalvertical'])."'
                    WHERE
                        question_id = '".Database::escape_string($form_content['shared_question_id'])."' AND
                        code = '".Database::escape_string($_course['id'])."'";
            Database::query($sql);
            $shared_question_id = $form_content['shared_question_id'];
        }

		return $shared_question_id;
	}

	/**
	 * This functions moves a question of a survey up or down
	 *
	 * @param string $direction
	 * @param integer $survey_question_id
	 * @param integer $survey_id
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
    public static function move_survey_question($direction, $survey_question_id, $survey_id)
    {
		// Table definition
		$table_survey_question 	= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$course_id = api_get_course_int_id();

		if ($direction == 'moveup') {
			$sort = 'DESC';
		}
		if ($direction == 'movedown') {
			$sort = 'ASC';
		}

		// Finding the two questions that needs to be swapped
		$sql = "SELECT * FROM $table_survey_question
		        WHERE c_id = $course_id AND survey_id='".Database::escape_string($survey_id)."'
		        ORDER BY sort $sort";
		$result = Database::query($sql);
		$found = false;
		while ($row = Database::fetch_array($result, 'ASSOC')) {
			if ($found) {
				$question_id_two = $row['question_id'];
				$question_sort_two = $row['sort'];
				$found = false;
			}
			if ($row['question_id'] == $survey_question_id) {
				$found = true;
				$question_id_one = $row['question_id'];
				$question_sort_one = $row['sort'];
			}
		}

		$sql1 = "UPDATE $table_survey_question SET sort = '".Database::escape_string($question_sort_two)."'
		        WHERE c_id = $course_id AND  question_id='".Database::escape_string($question_id_one)."'";
		Database::query($sql1);
		$sql2 = "UPDATE $table_survey_question SET sort = '".Database::escape_string($question_sort_one)."'
		        WHERE c_id = $course_id AND question_id='".Database::escape_string($question_id_two)."'";
		Database::query($sql2);
	}

	/**
	 * This function deletes all the questions of a given survey
	 * This function is normally only called when a survey is deleted
	 *
	 * @param int $survey_id the id of the survey that has to be deleted
	 * @return true
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
    public static function delete_all_survey_questions($survey_id, $shared = false)
    {
	    $course_id = api_get_course_int_id();

		// Table definitions
		$table_survey_question 	= Database :: get_course_table(TABLE_SURVEY_QUESTION);
        $course_condition = " c_id = $course_id AND ";
		if ($shared) {
		    $course_condition = "";
			$table_survey_question 	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION);
		}

		$sql = "DELETE FROM $table_survey_question
		        WHERE $course_condition survey_id='".Database::escape_string($survey_id)."'";

		// Deleting the survey questions

		Database::query($sql);

		// Deleting all the options of the questions of the survey
		survey_manager::delete_all_survey_questions_options($survey_id, $shared);

		// Deleting all the answers on this survey
		survey_manager::delete_all_survey_answers($survey_id);
	}

	/**
	 * This function deletes a survey question and all its options
	 *
	 * @param integer $survey_id the id of the survey
	 * @param integer $question_id the id of the question
	 * @param integer $shared
	 *
	 * @todo also delete the answers to this question
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version March 2007
	 */
    public static function delete_survey_question($survey_id, $question_id, $shared = false)
    {
        $course_id = api_get_course_int_id();
		// Table definitions
		$table_survey_question 	= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		if ($shared) {
			survey_manager::delete_shared_survey_question($survey_id, $question_id);
		}

		// Deleting the survey questions
		$sql = "DELETE FROM $table_survey_question
		        WHERE
		            c_id = $course_id AND
		            survey_id='".Database::escape_string($survey_id)."' AND
		            question_id='".Database::escape_string($question_id)."'";
		Database::query($sql);

		// Deleting the options of the question of the survey
		survey_manager::delete_survey_question_option($survey_id, $question_id, $shared);
	}

	/**
	 * This function deletes a shared survey question from the main database and all its options
	 *
	 * @param int $question_id the id of the question
	 * @param int $shared
	 *
	 * @todo delete all the options of this question
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version March 2007
	 */
    public static function delete_shared_survey_question($survey_id, $question_id)
    {
		// Table definitions
		$table_survey_question 	      = Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION);
		$table_survey_question_option = Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION_OPTION);

		// First we have to get the shared_question_id
		$question_data = survey_manager::get_question($question_id);

		// Deleting the survey questions
		$sql = "DELETE FROM $table_survey_question WHERE question_id='".Database::escape_string($question_data['shared_question_id'])."'";
		Database::query($sql);

		// Deleting the options of the question of the survey question
		$sql = "DELETE FROM $table_survey_question_option WHERE question_id='".Database::escape_string($question_data['shared_question_id'])."'";
		Database::query($sql);
	}

	/**
	 * SURVEY QUESTION OPTIONS FUNCTIONS
	 */

	/**
	 * This function stores the options of the questions in the table
	 *
	 * @param array $form_content
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @todo writing the update statement when editing a question
	 */
    public function save_question_options($form_content, $survey_data)
    {
	    $course_id = api_get_course_int_id();
		// A percentage question type has options 1 -> 100
		if ($form_content['type'] == 'percentage') {
			for($i = 1; $i < 101; $i++) {
				$form_content['answers'][] = $i;
			}
		}

		if (is_numeric($survey_data['survey_share']) && $survey_data['survey_share'] != 0) {
			survey_manager::save_shared_question_options($form_content, $survey_data);
		}

		// Table definition
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);

		// We are editing a question so we first have to remove all the existing options from the database
		if (is_numeric($form_content['question_id'])) {
			$sql = "DELETE FROM $table_survey_question_option
			        WHERE c_id = $course_id AND question_id = '".Database::escape_string($form_content['question_id'])."'";
			Database::query($sql);
		}

		$counter = 1;
		if (is_array($form_content['answers'])) {
			//foreach ($form_content['answers'] as $key => $answer) {
			for ($i = 0; $i < count($form_content['answers']); $i++) {
				$sql = "INSERT INTO $table_survey_question_option (c_id, question_id, survey_id, option_text, value,sort) VALUES (
                            $course_id,
                            '".Database::escape_string($form_content['question_id'])."',
                            '".Database::escape_string($form_content['survey_id'])."',
                            '".Database::escape_string($form_content['answers'][$i])."',
                            '".Database::escape_string($form_content['values'][$i])."',
                            '".Database::escape_string($counter)."')";
				Database::query($sql);
				$counter++;
			}
		}
	}

	/**
	 * This function stores the options of the questions in the shared table
	 *
	 * @param array $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 *
	 * @todo writing the update statement when editing a question
	 */
    public function save_shared_question_options($form_content, $survey_data)
    {
		if (is_array($form_content) && is_array($form_content['answers'])) {
			// Table defintion
			$table_survey_question_option 	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION_OPTION);

			// We are editing a question so we first have to remove all the existing options from the database
			$sql = "DELETE FROM $table_survey_question_option WHERE question_id = '".Database::escape_string($form_content['shared_question_id'])."'";
			Database::query($sql);

			$counter = 1;
			foreach ($form_content['answers'] as & $answer) {
				$sql = "INSERT INTO $table_survey_question_option (question_id, survey_id, option_text, sort) VALUES (
                            '".Database::escape_string($form_content['shared_question_id'])."',
                            '".Database::escape_string($survey_data['is_shared'])."',
                            '".Database::escape_string($answer)."',
                            '".Database::escape_string($counter)."')";
				Database::query($sql);
				$counter++;
			}
		}
	}

	/**
	 * This function deletes all the options of the questions of a given survey
	 * This function is normally only called when a survey is deleted
	 *
	 * @param $survey_id the id of the survey that has to be deleted
	 * @return true
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function delete_all_survey_questions_options($survey_id, $shared = false)
    {

		// Table definitions
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
        $course_id = api_get_course_int_id();
        $course_condition = " c_id = $course_id AND ";
		if ($shared) {
		    $course_condition = "";
			$table_survey_question_option 	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION_OPTION);
		}

        $sql = "DELETE FROM $table_survey_question_option
                WHERE $course_condition survey_id='".Database::escape_string($survey_id)."'";

		// Deleting the options of the survey questions
		Database::query($sql);
		return true;
	}

	/**
	 * This function deletes the options of a given question
	 *
	 * @param int $survey_id
	 * @param int $question_id
	 * @param int $shared
	 * @return bool
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
     * @author Julio Montoya
	 * @version March 2007
	 */
    public static function delete_survey_question_option($survey_id, $question_id, $shared = false)
    {
	    $course_id = api_get_course_int_id();
        $course_condition = " c_id = $course_id AND ";

		// Table definitions
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		if ($shared) {
		    $course_condition = "";
			$table_survey_question_option 	= Database :: get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION_OPTION);
		}

		// Deleting the options of the survey questions
		$sql = "DELETE from $table_survey_question_option
		        WHERE
		            $course_condition survey_id='".Database::escape_string($survey_id)."' AND
		            question_id='".Database::escape_string($question_id)."'";
		Database::query($sql);
		return true;
	}

	/**
	 * SURVEY ANSWERS FUNCTIONS
	 */

	/**
	 * This function deletes all the answers anyone has given on this survey
	 * This function is normally only called when a survey is deleted
	 *
	 * @param $survey_id the id of the survey that has to be deleted
	 * @return true
	 *
	 * @todo write the function
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007,december 2008
	 */
    public static function delete_all_survey_answers($survey_id)
    {
        $course_id = api_get_course_int_id();
		$table_survey_answer = Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$survey_id = intval($survey_id);
		Database::query("DELETE FROM $table_survey_answer WHERE c_id = $course_id AND survey_id=$survey_id");
		return true;
	}

    /**
     * @param int $user_id
     * @param int $survey_id
     * @param int $course_id
     * @return bool
     */
    public static function is_user_filled_survey($user_id, $survey_id, $course_id)
    {
		$table_survey_answer = Database :: get_course_table(TABLE_SURVEY_ANSWER);

		$user_id	= intval($user_id);
		$course_id	= intval($course_id);
		$survey_id	= intval($survey_id);

		$sql = "SELECT DISTINCT user FROM $table_survey_answer
                WHERE
                    c_id		= $course_id AND
                    user		= $user_id AND
                    survey_id	= $survey_id";
        $result = Database::query($sql);
		if (Database::num_rows($result)) {
			return true;
		}
		return false;
	}

	/**
	 * This function gets all the persons who have filled the survey
	 *
	 * @param integer $survey_id
	 * @return array
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function get_people_who_filled_survey($survey_id, $all_user_info = false, $course_id = null)
    {
		// Database table definition
		$table_survey_answer 		= Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$table_user					= Database :: get_main_table(TABLE_MAIN_USER);

		// Variable initialisation
		$return = array();

		if (empty($course_id)) {
            $course_id  = api_get_course_int_id();
        } else {
            $course_id = intval($course_id);
        }

		if ($all_user_info) {
			$order_clause = api_sort_by_first_name() ? ' ORDER BY user.firstname, user.lastname' : ' ORDER BY user.lastname, user.firstname';
			$sql = "SELECT DISTINCT
			            answered_user.user as invited_user, user.firstname, user.lastname, user.user_id
                    FROM $table_survey_answer answered_user
                    LEFT JOIN $table_user as user ON answered_user.user = user.user_id
                    WHERE
                        answered_user.c_id = $course_id AND
                        survey_id= '".Database::escape_string($survey_id)."' ".
                    $order_clause;
		} else {
			$sql = "SELECT DISTINCT user FROM $table_survey_answer
			        WHERE c_id = $course_id AND survey_id= '".Database::escape_string($survey_id)."'  ";
		}

		$res = Database::query($sql);
		while ($row = Database::fetch_array($res, 'ASSOC')) {
			if ($all_user_info) {
				$return[] = $row;
			} else {
				$return[] = $row['user'];
			}
		}
		return $return;
	}

    static function survey_generation_hash_available()
    {
        if (extension_loaded('mcrypt')) {
            return true;
        }
        return false;
    }

    static function generate_survey_hash($survey_id, $course_id, $session_id, $group_id)
    {
        $hash = hash('sha512', api_get_security_key().'_'.$course_id.'_'.$session_id.'_'.$group_id.'_'.$survey_id);
        return $hash;
    }

    static function validate_survey_hash($survey_id, $course_id, $session_id, $group_id, $hash)
    {
        $survey_generated_hash = self::generate_survey_hash($survey_id, $course_id, $session_id, $group_id);
        if ($survey_generated_hash == $hash) {
            return true;
        }
        return false;
    }

    static function generate_survey_link($survey_id, $course_id, $session_id, $group_id)
    {
        $code = self::generate_survey_hash($survey_id, $course_id, $session_id, $group_id);
        return api_get_path(WEB_CODE_PATH).'survey/link.php?h='.$code.'&i='.$survey_id.'&c='.intval($course_id).'&s='.intval($session_id).'&g='.$group_id;
    }
}


class survey_question
{

	// The html code of the form
	public $html;

	/**
	 * This function does the generic part of any survey question: the question field
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @todo the form_text has to become a wysiwyg editor or adding a question_comment field
	 * @todo consider adding a question_comment form element
	 */
	function create_form($survey_data, $form_content)
    {
        $action = isset($_GET['action']) ? Security::remove_XSS($_GET['action']) : null;
        $questionId = isset($_GET['question_id']) ? Security::remove_XSS($_GET['question_id']) : null;
		$tool_name = Display::return_icon(
            survey_manager::icon_question(Security::remove_XSS($_GET['type'])),
            get_lang(ucfirst(Security::remove_XSS($_GET['type']))),
            array('align' => 'middle', 'height' => '22px')
        ).' ';

		if ($action == 'add') {
			$tool_name .= get_lang('AddQuestion');
		}
		if ($action == 'edit') {
			$tool_name .= get_lang('EditQuestion');
		}

		if ($_GET['type'] == 'yesno') {
			$tool_name .= ': '.get_lang('YesNo');
		} else if ($_GET['type'] == 'multiplechoice') {
			$tool_name .= ': '.get_lang('UniqueSelect');
		} else {
			$tool_name .= ': '.get_lang(api_ucfirst(Security::remove_XSS($_GET['type'])));
		}

        $url = api_get_self().'?action='.$action.'&type='.Security::remove_XSS($_GET['type']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'&question_id='.$questionId;

		$this->html .= '<form class="form-horizontal" id="question_form" name="question_form" method="post" action="'.$url.'">';
        $this->html .= '<legend>'.$tool_name.'</legend>';
		$this->html .= '		<input type="hidden" name="survey_id" id="survey_id" value="'.Security::remove_XSS($_GET['survey_id']).'"/>';
		$this->html .= '		<input type="hidden" name="question_id" id="question_id" value="'.$questionId.'"/>';
		$this->html .= '		<input type="hidden" name="shared_question_id" id="shared_question_id" value="'.Security::remove_XSS($form_content['shared_question_id']).'"/>';
		$this->html .= '		<input type="hidden" name="type" id="type" value="'.Security::remove_XSS($_GET['type']).'"/>';

		// question field
		$this->html .= '	<div class="control-group">';
		$this->html .= '		<label class="control-label">';
		$this->html .= '			<span class="form_required">*</span> '.get_lang('Question');
		$this->html .= '		</label>';
		$this->html .= '		<div class="controls">';
		$this->html .= api_return_html_area('question', Security::remove_XSS(stripslashes($form_content['question']), STUDENT), '', '', null, array('ToolbarSet' => 'Survey', 'Width' => '100%', 'Height' => '120'));
		$this->html .= '		</div>';
		$this->html .= '	</div>';

		if ($survey_data['survey_type'] == 1) {
			$table_survey_question_group = Database::get_course_table(TABLE_SURVEY_QUESTION_GROUP);
			$sql = 'SELECT id,name FROM '.$table_survey_question_group.' WHERE survey_id = '.(int)$_GET['survey_id'].' ORDER BY name';
			$rs = Database::query($sql);

			while ($row = Database::fetch_array($rs, 'NUM')) {
				$glist .= '<option value="'.$row[0].'" >'.$row[1].'</option>';
			}

			$grouplist = $grouplist1 = $grouplist2 = $glist;

			if (!empty($form_content['assigned'])) {
				$grouplist = str_replace('<option value="'.$form_content['assigned'].'"','<option value="'.$form_content['assigned'].'" selected',$glist);
			}

			if (!empty($form_content['assigned1'])) {
				$grouplist1 = str_replace('<option value="'.$form_content['assigned1'].'"','<option value="'.$form_content['assigned1'].'" selected',$glist);
			}

			if (!empty($form_content['assigned2'])) {
				$grouplist2 = str_replace('<option value="'.$form_content['assigned2'].'"','<option value="'.$form_content['assigned2'].'" selected',$glist);
			}

			$this->html .= '	<tr><td colspan="">
			<fieldset style="border:1px solid black"><legend>'.get_lang('Condition').'</legend>

			<b>'.get_lang('Primary').'</b><br />
			'.'<input type="radio" name="choose" value="1" '.(($form_content['choose'] == 1) ? 'checked' : '').
			'><select name="assigned">'.$grouplist.'</select><br />';

			$this->html .= '
			<b>'.get_lang('Secondary').'</b><br />
			'.'<input type="radio" name="choose" value="2" '.(($form_content['choose']==2)?'checked':'').
			'><select name="assigned1">'.$grouplist1.'</select> '.
			'<select name="assigned2">'.$grouplist2.'</select>'
			.'</fieldset><br />';
		}

		return $this->html;
	}

	/**
	 * This functions displays the form after the html variable has correctly been finished
	 * (adding a submit button, closing the table and closing the form)
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 */
	function render_form()
    {
		if (isset($_GET['question_id']) and !empty($_GET['question_id'])) {
			$class = 'save';
			$text = get_lang('ModifyQuestionSurvey');
		} else {
			$class = 'add';
			$text = get_lang('CreateQuestionSurvey');
		}

		if ($_GET['type'] == 'yesno' || $_GET['type'] == 'open'|| $_GET['type'] == 'percentage' || $_GET['type'] == 'comment' || $_GET['type'] == 'pagebreak') {
			$this->html .= '	<div class="control-group">';
			$this->html .= '		<div class="controls">';
		}
		$this->html .= '			<button class="'.$class.'"type="submit" name="save_question">'.$text.'</button>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';

		//$this->html .= '	</table>';

		$this->html .= '</form>';
		echo $this->html;
	}

	/**
	 * This function handles the actions on a question and its answers
	 *
	 * @todo consider using $form_content instead of $_POST
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function handle_action($survey_data, $form_content)
    {
	    $course_id = api_get_course_int_id();
		global $config;

		// Moving an answer up
		if ($_POST['move_up']) {
			foreach ($_POST['move_up'] as $key => & $value) {
				$id1		= $key;
				$content1 	= $form_content['answers'][$id1];
				$id2		= $key - 1;
				$content2	= $form_content['answers'][$id2];
				$form_content['answers'][$id1] = $content2;
				$form_content['answers'][$id2] = $content1;
			}
		}

		// Moving an answer down
		if ($_POST['move_down']) {
			foreach ($_POST['move_down'] as $key => & $value) {
				$id1		= $key;
				$content1 	= $form_content['answers'][$id1];
				$id2		= $key + 1;
				$content2	= $form_content['answers'][$id2];
				$form_content['answers'][$id1] = $content2;
				$form_content['answers'][$id2] = $content1;
			}
		}

		// Adding an answer
		if (isset($_POST['add_answer'])) {
			$form_content['answers'][] = '';
		}

		// Removing an answer
		if (isset($_POST['remove_answer'])) {
			$max_answer = count($form_content['answers']);
			unset($form_content['answers'][$max_answer - 1]);
		}

		// Saving a question
		if (isset($_POST['save_question'])) {
			$message = survey_manager::save_question(
                $survey_data,
                $form_content
            );

			if ($message == 'QuestionAdded' || $message == 'QuestionUpdated' ) {
				$sql='SELECT COUNT(*) FROM '.Database :: get_course_table(TABLE_SURVEY_QUESTION).' WHERE c_id = '.$course_id.' AND survey_id = '.intval($_GET['survey_id']);
				$res = Database :: fetch_array (Database::query($sql));

				if ($config['survey']['debug']) {
					Display :: display_header();
					Display :: display_confirmation_message($message.'<br />'.get_lang('ReturnTo').' <a href="'.api_get_path(WEB_CODE_PATH).'survey/survey.php?survey_id='.intval($_GET['survey_id']).'">'.get_lang('Survey').'</a>', false);
				} else {
					header('Location: '.api_get_path(WEB_CODE_PATH).'survey/survey.php?survey_id='.intval($_GET['survey_id']).'&message='.$message);
                    exit;
				}
			} else {
				if ($message == 'PleaseEnterAQuestion' || $message == 'PleasFillAllAnswer'|| $message == 'PleaseChooseACondition'|| $message == 'ChooseDifferentCategories') {
					$_SESSION['temp_user_message'] = $form_content['question'];
					$_SESSION['temp_horizontalvertical'] = $form_content['horizontalvertical'];
					$_SESSION['temp_sys_message'] = $message;
					$_SESSION['temp_answers'] = $form_content['answers'];
					$_SESSION['temp_values'] = $form_content['values'];
					header('location: '.api_get_path(WEB_CODE_PATH).'survey/question.php?'.api_get_cidreq().'&question_id='.intval($_GET['question_id']).'&survey_id='.intval($_GET['survey_id']).'&action='.Security::remove_XSS($_GET['action']).'&type='.Security::remove_XSS($_GET['type']).'');
                    exit;
				}
			}
		}

		/**
		 * This solution is a little bit strange but I could not find a different solution.
		 */
		if ($_POST['delete_answer']) {
			foreach ($_POST['delete_answer'] as $key => & $value) {
				unset($form_content['answers'][$key]);
				$deleted = $key;
			}
			foreach ($form_content['answers'] as $key => & $value) {
				if ($key > $deleted) {
					$form_content['answers'][$key - 1] = $form_content['answers'][$key];
					unset($form_content['answers'][$key]);
				}
			}
		}
		return $form_content;
	}

	/**
	 * This functions adds two buttons. One to add an option, one to remove an option
	 *
	 * @param string $form_content
	 * @return string code
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
     * @author Julio Montoya - 2013
	 * @version January 2007
	 */
	function add_remove_buttons($form_content)
    {
		if (count($form_content['answers']) <= 2) {
			$remove_answer_attribute = 'disabled="disabled"';
		}

		$return = '	<div class="row">';
		$return .= '		<div class="formw">';
		$return .= '		<input type="hidden" name="is_executable" id="is_executable" value="-" />';
		$return .= '			<button class="minus" type="submit" name="remove_answer" "'.$remove_answer_attribute.'">'.get_lang('RemoveAnswer').' </button>';
		$return .= '			<button class="plus" type="submit" name="add_answer">'.get_lang('AddAnswer').'</button>';

		return $return;
	}

	/**
	 * Render the question. In this case this starts with the form tag
	 *
	 * @param string $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content)
    {
		$this->html = '<form id="question" name="question" method="post" action="'.api_get_self().'?survey_id='.intval($_GET['survey_id']).'">';
		echo $this->html;
	}
}

class ch_yesno extends survey_question
{

	/**
	 * This function creates the form elements for the yesno questions
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
		// Horizontal or vertical
		$this->html .= '	<div class="control-group">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('DisplayAnswersHorVert');
		$this->html .= '		</label>';
		$this->html .= '		<div class="controls">';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="horizontal" ';
		if (empty($form_content['horizontalvertical']) or $form_content['horizontalvertical'] == 'horizontal') {
			$this->html .= 'checked="checked"';
		}
		$this->html .= '/>'.get_lang('Horizontal').'<br />';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="vertical" ';
		if ($form_content['horizontalvertical'] == 'vertical') {
			$this->html .= 'checked="checked"';
		}
		$this->html .= ' />'.get_lang('Vertical').'';
		$this->html .= '		</div>';
		$this->html .= '	</div>';

		// The options
		$this->html .= '	<div class="row">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('AnswerOptions');
		$this->html .= '		</label>';
		$this->html .= '		<div class="formw">';
		$this->html .= '			<table>';
		$this->html .= '	<tr>';
		$this->html .= '		<td align="right"><label for="answers[0]">1</label></td>';

		$this->html .= '		<td width="550">'.api_return_html_area('answers[0]', stripslashes($form_content['answers'][0]), '', '', null, array('ToolbarSet' => 'Survey', 'Width' => '100%', 'Height' => '120')).'</td>';
		$this->html .= '		<td><input style="width:22px" src="../img/icons/22/down.png"  type="image" class="down" value="move_down[0]" name="move_down[0]"/></td>';
		$this->html .= '	</tr>';
		$this->html .= '	<tr>';
		$this->html .= '		<td align="right"><label for="answers[1]">2</label></td>';
		//$this->html .= '		<td><input type="text" name="answers[1]" id="answers[1]" value="'.$form_content['answers'][1].'" /></td>';
		$this->html .= '		<td width="550">'.api_return_html_area('answers[1]', stripslashes($form_content['answers'][1]), '', '', null, array('ToolbarSet' => 'Survey', 'Width' => '100%', 'Height' => '120')).'</td>';
		$this->html .= '		<td><input style="width:22px" type="image" src="../img/icons/22/up.png" value="move_up[1]" name="move_up[1]" /></td>';
		$this->html .= '	</tr>';
		$this->html .= '			</table>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';
	}

	/**
	 * Render the yes not question type
	 *
	 * @param string $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content, $answers = array())
    {
		if (is_array($form_content['options'])) { // Check if data is correct
			foreach ($form_content['options'] as $key => & $value) {
                if ($form_content['display'] == 'vertical') {
                    $this->html .= '<label class="radio">';
                } else {
                    $this->html .= '<label class="radio inline">';
                }
                $value_to_show = $value;

                if (substr_count($value, '<p>') == 1) {
                    $value_to_show = substr($value, 3, (strlen($value) - 7));
				}
                $this->html .= '<input name="question'.$form_content['question_id'].'" type="radio" value="'.$key.'"';
				if (is_array($answers)) {
					if (in_array($key,$answers)) {
						$this->html .= 'checked="checked"';
					}
				}
                $this->html .= '/>';
                $this->html .= $value_to_show.'</label>';
                if ($form_content['display'] == 'vertical') {
						//$this->html .= '<br />';
                }
			}
		}
		echo '<div class="survey_question_wrapper">';
            echo '<div class="survey_question">'.$form_content['survey_question'].'</div>';
            echo $this->html;
		echo '</div>';
	}
}

class ch_multiplechoice extends survey_question
{

	/**
	 * This function creates the form elements for the multiple choice questions
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
		// Horizontal or vertical
		$this->html .= '	<div class="row">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('DisplayAnswersHorVert');
		$this->html .= '		</label>';
		$this->html .= '		<div class="formw">';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="horizontal" ';
		if (empty($form_content['horizontalvertical']) or $form_content['horizontalvertical'] == 'horizontal') {
			$this->html .= 'checked="checked"';
		}
		$this->html .= '/>'.get_lang('Horizontal').'</label><br />';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="vertical" ';
		if ($form_content['horizontalvertical'] == 'vertical') {
			$this->html .= 'checked="checked"';
		}
		$this->html .= ' />'.get_lang('Vertical').'</label>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';

		// The Options
		$this->html .= '	<div class="row">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('AnswerOptions');
		$this->html .= '		</label>';
		$this->html .= '		<div class="formw">';
		$total_number_of_answers = count($form_content['answers']);
		$this->html .= ' 			<table>';
		if (is_array($form_content['answers'])) { // Check if data is correct
			foreach ($form_content['answers'] as $key => $value) {
				$this->html .= '	<tr>';
				$this->html .= '		<td align="right"><label for="answers['.$key.']">'.($key+1).'</label></td>';
				//$this->html .= '		<td><input type="text" name="answers['.$key.']" id="answers['.$key.']" value="'.$form_content['answers'][$key].'" /></td>';
				$this->html .= '		<td width="550">'.api_return_html_area('answers['.$key.']', api_html_entity_decode(stripslashes($form_content['answers'][$key]), ENT_QUOTES), '', '', null, array('ToolbarSet' => 'Survey', 'Width' => '100%', 'Height' => '120')).'</td>';
				$this->html .= '		<td>';
				if ($key<$total_number_of_answers-1) {
					$this->html .= '			<input style="width:22px" type="image" src="../img/icons/22/down.png"  value="move_down['.$key.']" name="move_down['.$key.']"/>';
				}
				if ($key>0) {
					$this->html .= '			<input style="width:22px" type="image" src="../img/icons/22/up.png"  value="move_up['.$key.']" name="move_up['.$key.']"/>';
				}
				if ($total_number_of_answers> 2) {
					$this->html .= '			<input style="width:22px" type="image" src="../img/icons/22/delete.png"  value="delete_answer['.$key.']" name="delete_answer['.$key.']"/>';
				}
				$this->html .= ' 		</td>';
				$this->html .= '	</tr>';
			}
		}
		// The buttons for adding or removing
		$this->html .= ' 			</table>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';

		$this->html .= parent :: add_remove_buttons($form_content);
	}

	/**
	 * render the multiple choice question type
	 *
	 * @param string $form_content
	 *
	 * @todo it would make more sense to consider yesno as a special case of multiplechoice and not the other way around
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content, $answers = array())
    {
		$question = new ch_yesno();
		$question->render_question($form_content, $answers);
	}
}

class ch_personality extends survey_question
{

	/**
	 * This function creates the form elements for the multiple response questions
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
		$this->html .= '	<tr>';
		$this->html .= '		<td colspan="2"><strong>'.get_lang('DisplayAnswersHorVert').'</strong></td>';
		$this->html .= '	</tr>';
		// Horizontal or vertical
		$this->html .= '	<tr>';
		$this->html .= '		<td align="right" valign="top">&nbsp;</td>';
		$this->html .= '		<td>';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="horizontal" ';
		if (empty($form_content['horizontalvertical']) || $form_content['horizontalvertical'] == 'horizontal') {
			$this->html .= 'checked="checked"';
		}
		$this->html .= '/>'.get_lang('Horizontal').'</label><br />';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="vertical" ';

		if ($form_content['horizontalvertical'] == 'vertical') {
			$this->html .= 'checked="checked"';
		}

		$this->html .= ' />'.get_lang('Vertical').'</label>';
		$this->html .= '		</td>';
		$this->html .= '		<td>&nbsp;</td>';
		$this->html .= '	</tr>';
		$this->html .= '		<tr>
								<td colspan="">&nbsp;</td>
							</tr>';

		// The options
		$this->html .= '	<tr>';
		$this->html .= '		<td colspan="3"><strong>'.get_lang('AnswerOptions').'</strong></td>';
		$this->html .= '	</tr>';
		$total_number_of_answers = count($form_content['answers']);

		$question_values = array();

		// Values of question options
		if (is_array($form_content['values'])) { // Check if data is correct
			foreach ($form_content['values'] as $key => & $value) {
				$question_values [] = '<input size="3" type="text" id="values['.$key.']" name="values['.$key.']" value="'.$value.'" />';
			}
		}
		$count = 0;
		if (is_array($form_content['answers'])) {
			foreach ($form_content['answers'] as $key => & $value) {
				$this->html .= '	<tr>';
				$this->html .= '		<td align="right"><label for="answers['.$key.']">'.($key+1).'</label></td>';
				//$this->html .= '		<td><input type="text" name="answers['.$key.']" id="answers['.$key.']" value="'.$form_content['answers'][$key].'" /></td>';
				$this->html .= '		<td width="550">'.api_return_html_area('answers['.$key.']', api_html_entity_decode(stripslashes($form_content['answers'][$key])), '', '', null, array('ToolbarSet' => 'Survey', 'Width' => '100%', 'Height' => '120')).'</td>';
				$this->html .= '		<td>';

				if ($total_number_of_answers > 2) {
					$this->html .= $question_values[$count];
				}

				if ($key < $total_number_of_answers - 1) {
					$this->html .= '		<input type="image" style="width:22px"   src="../img/icons/22/down.png"  value="move_down['.$key.']" name="move_down['.$key.']"/>';
				}
				if ($key > 0) {
					$this->html .= '		<input type="image" style="width:22px"   src="../img/icons/22/up.png"  value="move_up['.$key.']" name="move_up['.$key.']"/>';
				}
				if ($total_number_of_answers > 2) {
					$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/delete.png"  value="delete_answer['.$key.']" name="delete_answer['.$key.']"/>';
				}
				$this->html .= ' 		</td>';
				$this->html .= '	</tr>';
				$count++;
			}
		}
		// The buttons for adding or removing
		//$this->html .= parent :: add_remove_buttons($form_content);
	}

	/**
	 * Render the multiple response question type
	 *
	 * @param string $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content, $answers = array()) {
		$question = new ch_yesno();
		$question->render_question($form_content, $answers);
	}
}

class ch_multipleresponse extends survey_question
{

	/**
	 * This function creates the form elements for the multiple response questions
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function create_form($survey_data, $form_content) {

		$this->html = parent::create_form($survey_data, $form_content);
		// Horizontal or vertical
		$this->html .= '	<div class="row">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('DisplayAnswersHorVert');
		$this->html .= '		</label>';
		$this->html .= '		<div class="formw">';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="horizontal" ';
		if (empty($form_content['horizontalvertical']) || $form_content['horizontalvertical'] == 'horizontal') {
			$this->html .= 'checked="checked"';
		}
		$this->html .= '/>'.get_lang('Horizontal').'</label><br />';
		$this->html .= '		  <input name="horizontalvertical" type="radio" value="vertical" ';
		if ($form_content['horizontalvertical'] == 'vertical') {
			$this->html .= 'checked="checked"';
		}
		$this->html .= ' />'.get_lang('Vertical').'</label>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';

		// The options
		$this->html .= '	<div class="row">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('AnswerOptions');
		$this->html .= '		</label>';
		$this->html .= '		<div class="formw">';
		$total_number_of_answers = count($form_content['answers']);
		$this->html .= ' 			<table>';
		if (is_array($form_content['answers'])) { // Values of question options
			foreach ($form_content['answers'] as $key => & $value) {
				$this->html .= '	<tr>';
				$this->html .= '		<td align="right"><label for="answers['.$key.']">'.($key + 1).'</label></td>';
				//$this->html .= '		<td><input type="text" name="answers['.$key.']" id="answers['.$key.']" value="'.$form_content['answers'][$key].'" /></td>';
				$this->html .= '		<td width="550">'.api_return_html_area('answers['.$key.']', api_html_entity_decode(stripslashes($form_content['answers'][$key]), ENT_QUOTES), '', '', null, array('ToolbarSet' => 'Survey', 'Width' => '100%', 'Height' => '120')).'</td>';
				$this->html .= '		<td>';
				if ($key<$total_number_of_answers - 1) {
					$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/down.png"  value="move_down['.$key.']" name="move_down['.$key.']"/>';
				}

				if ($key > 0) {
					$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/up.png"  value="move_up['.$key.']" name="move_up['.$key.']"/>';
				}

				if ($total_number_of_answers > 2) {
					$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/delete.png"  value="delete_answer['.$key.']" name="delete_answer['.$key.']"/>';
				}
				$this->html .= ' 		</td>';
				$this->html .= '	</tr>';
			}
		}
		// The buttons for adding or removing
		$this->html .= ' 			</table>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';
		$this->html .= parent :: add_remove_buttons($form_content);
	}

	/**
	 * Render the multiple response question type
	 *
	 * @param unknown_type $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content, $answers = array())
    {
		foreach ($form_content['options'] as $key => & $value) {
			if ($form_content['display'] == 'vertical') {
			    $this->html .= '<label class="checkbox"><input name="question'.$form_content['question_id'].'[]" type="checkbox" value="'.$key.'"';
            } else {
                $this->html .= '<label class="checkbox inline"><input name="question'.$form_content['question_id'].'[]" type="checkbox" value="'.$key.'"';
            }
			if (is_array($answers)) {
				if (in_array($key, $answers)) {
					$this->html .= 'checked="checked"';
				}
			}
			if (substr_count($value, '<p>') == 1) {
				$this->html .= '/>'.substr($value, 3, (strlen($value) - 7)).'</label>';
				if ($form_content['display'] == 'vertical') {
					$this->html .= '<br />';
				}
			} else {
				$this->html .= '/>'.$value.'</label>';
			}
		}
		echo '<div class="survey_question_wrapper">';
		echo '<div class="survey_question">'.$form_content['survey_question'].'</div>';
		echo '<div class="control-group">';
		echo $this->html;
		echo '</div>';
		echo '</div>';
	}
}

class ch_dropdown extends survey_question
{

	/**
	 * This function creates the form elements for the dropdown questions
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
		// The answers
		$this->html .= '	<div class="row">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('AnswerOptions');
		$this->html .= '		</label>';
		$this->html .= '		<div class="formw">';
		$total_number_of_answers = count($form_content['answers']);
		$this->html .= ' 			<table>';
		foreach ($form_content['answers'] as $key => & $value) {
			$this->html .= '	<tr>';
			$this->html .= '		<td align="right"><label for="answers['.$key.']">'.($key + 1).'</label></td>';
			$this->html .= '		<td><input type="text" name="answers['.$key.']" id="answers['.$key.']" value="'.stripslashes($form_content['answers'][$key]).'" /></td>';
			$this->html .= '		<td>';
			if ($key < $total_number_of_answers - 1) {
				$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/down.png"  value="move_down['.$key.']" name="move_down['.$key.']"/>';
			}
			if ($key > 0) {
				$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/up.png"  value="move_up['.$key.']" name="move_up['.$key.']"/>';
			}
			if ($total_number_of_answers> 2) {
				$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/delete.png"  value="delete_answer['.$key.']" name="delete_answer['.$key.']"/>';
			}
			$this->html .= ' 		</td>';
			$this->html .= '	</tr>';
		}
		// The buttons for adding or removing
		$this->html .= ' 			</table>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';
		$this->html .= parent :: add_remove_buttons($form_content);
	}

	/**
	 * Render the dropdown question type
	 *
	 * @param unknown_type $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content, $answers = array())
    {
		foreach ($form_content['options'] as $key => & $value) {
			$this->html .= '<option value="'.$key.'" ';
			if (is_array($answers)) {
				if (in_array($key, $answers)) {
					$this->html .= 'selected="selected"';
				}
			}
			$this->html .= '>'.$value.'</option>';
		}

		echo '<div class="survey_question_wrapper">';
		echo '<div class="survey_question">'.$form_content['survey_question'].'</div>';
		echo '<div class="survey_question_options">';
		echo '<select name="question'.$form_content['question_id'].'" id="select">';
		echo $this->html;
		echo '</select>';
		echo '</div>';
		echo '</div>';
		/*
			<option value="test">test</option>
		*/
	}
}


class ch_open extends survey_question
{

	/**
	 * This function creates the form elements for the open questions
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @todo add a limit for the number of characters that can be type
	 * @todo add a checkbox weither the answer is a textarea or a wysiwyg editor
	 */
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
	}

	/**
	 * render the open question type
	 *
	 * @param unknown_type $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content, $answers = array())
    {
		echo '<div class="survey_question_wrapper">';
		echo '<div class="survey_question">'.$form_content['survey_question'].'</div>';
		echo '<div class="survey_question_options">';
		if (is_array($answers)) {
			$content = implode('', $answers);
		} else {
			$content = $answers;
		}
		echo '<label for="question'.$form_content['question_id'].'"></label>
              <textarea name="question'.$form_content['question_id'].'" id="textarea" style="width: 400px; height: 130px;">'.$content.'</textarea>';
		echo '</div>';
		echo '</div>';
	}
}


class ch_comment extends survey_question
{

	/**
	 * This function creates the form elements for a comment.
	 * A comment is nothing more than a block of text that the user can read
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @param array $form_content
	 */
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
	}

	/**
	 * Render the comment "question" type
	 *
	 * @param unknown_type $form_content
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	function render_question($form_content)
    {
		echo '<div class="survey_question_wrapper">';
		echo '<div class="survey_question">'.$form_content['survey_question'].'</div>';
		echo '</div>';
	}
}

class ch_pagebreak extends survey_question
{

	/**
	 * This function creates the form elements for a comment.
	 * A comment is nothing more than a block of text that the user can read
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @param array $form_content
	 */
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
	}
}


class ch_percentage extends survey_question
{
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
	}

	function render_question($form_content, $answers = array()) {
		$this->html .= '<option value="--">--</option>';
		foreach ($form_content['options'] as $key => & $value) {
			$this->html .= '<option value="'.$key.'" ';
			if (is_array($answers)) {
				if (in_array($key, $answers)) {
					$this->html .= 'selected="selected"';
				}
			}
			$this->html .= '>'.$value.'</option>';
		}
		echo '<div class="survey_question_wrapper">';
		echo '<div class="survey_question">'.$form_content['survey_question'].'</div>';
		echo '<div class="survey_question_options">';
		echo '<select name="question'.$form_content['question_id'].'" id="select">';
		echo $this->html;
		echo '</select>';
		echo '</div>';
		echo '</div>';
	}
}

class ch_score extends survey_question
{
	function create_form($survey_data, $form_content)
    {
		$this->html = parent::create_form($survey_data, $form_content);
		// The maximum score that can be given
		$this->html .= '	<div class="control-group">';
		$this->html .= '		<label class="control-label">';
		$this->html .= '			<span class="form_required">*</span>'.get_lang('MaximumScore');
		$this->html .= '		</label>';
		$this->html .= '		<div class="controls">';
		$this->html .= '			<input type="text" name="maximum_score" value="'.$form_content['maximum_score'].'">';
		$this->html .= '		</div>';
		$this->html .= '	</div>';

		// The answers
		$this->html .= '	<div class="row">';
		$this->html .= '		<label class="control-label">';
		$this->html .= 				get_lang('AnswerOptions');
		$this->html .= '		</label>';
		$this->html .= '		<div class="formw">';
		$total_number_of_answers = count($form_content['answers']);
		$this->html .= ' 			<table>';
		foreach ($form_content['answers'] as $key => & $value) {
			$this->html .= '	<tr>';
			$this->html .= '		<td align="right"><label for="answers['.$key.']">'.($key+1).'</label></td>';
			//$this->html .= '		<td><input type="text" name="answers['.$key.']" id="answers['.$key.']" value="'.$form_content['answers'][$key].'" /></td>';
			$this->html .= '		<td width="550">'.api_return_html_area('answers['.$key.']', stripslashes($form_content['answers'][$key]), '', '', null, array('ToolbarSet' => 'Survey', 'Width' => '100%', 'Height' => '120')).'</td>';
			$this->html .= '		<td>';
			if ($key<$total_number_of_answers - 1) {
				$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/down.png"  value="move_down['.$key.']" name="move_down['.$key.']"/>';
			}
			if ($key > 0) {
				$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/up.png"  value="move_up['.$key.']" name="move_up['.$key.']"/>';
			}
			if ($total_number_of_answers > 2) {
				$this->html .= '			<input type="image" style="width:22px"   src="../img/icons/22/delete.png"  value="delete_answer['.$key.']" name="delete_answer['.$key.']"/>';
			}
			$this->html .= ' 		</td>';
			$this->html .= '	</tr>';
		}
		// The buttons for adding or removing
		$this->html .= ' 			</table>';
		$this->html .= '		</div>';
		$this->html .= '	</div>';
		$this->html .= parent :: add_remove_buttons($form_content);
	}

	function render_question($form_content, $answers = array())
    {
		/*
		echo '<div style="border: 1px solid red;">';
		echo '<pre>';
		print_r($answers);
		echo '</pre></div>';
		*/
		$this->html = '<table>';
		foreach ($form_content['options'] as $key => & $value) {
			$this->html .= '<tr>
								<td>'.$value.'</td>';
			$this->html .= '	<td>';
			$this->html .= '<select name="question'.$form_content['question_id'].'['.$key.']">';
			$this->html .= '<option value="--">--</option>';
			for ($i=1; $i <= $form_content['maximum_score']; $i++) {
				$this->html .= '<option value="'.$i.'"';
				if ($answers[$key] == $i) {
					$this->html .= 'selected="selected" ';
				}
				$this->html .= '>'.$i.'</option>';
			}
			$this->html .= '</select>';
			$this->html .= '	</td>';
			$this->html .= '</tr>';
		}
		$this->html .= '</table>';
		echo '<div class="survey_question_wrapper">';
		echo '<div class="survey_question">'.$form_content['survey_question'].'</div>';
		echo '<div class="survey_question_options">';
		//echo '<select name="question'.$form_content['question_id'].'" id="select">';
		echo $this->html;
		//echo '</select>';
		echo '</div>';
		echo '</div>';
	}
}


/**
 * This class offers a series of general utility functions for survey querying and display
 * @package chamilo.survey
 */
class SurveyUtil
{

	/**
	 * Checks whether the given survey has a pagebreak question as the first or the last question.
	 * If so, break the current process, displaying an error message
	 * @param	integer	Survey ID (database ID)
	 * @param	boolean	Optional. Whether to continue the current process or exit when breaking condition found. Defaults to true (do not break).
	 * @return	void
	 */
	static function check_first_last_question($survey_id, $continue = true)
    {
		// Table definitions
		$tbl_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
        $course_id = api_get_course_int_id();

		// Getting the information of the question
		$sql = "SELECT * FROM $tbl_survey_question WHERE c_id = $course_id AND survey_id='".Database::escape_string($survey_id)."' ORDER BY sort ASC";
		$result = Database::query($sql);
		$total = Database::num_rows($result);
		$counter = 1;
		$error = false;
		while ($row = Database::fetch_array($result, 'ASSOC')) {
			if ($counter == 1 && $row['type'] == 'pagebreak') {
				Display::display_error_message(get_lang('PagebreakNotFirst'), false);
				$error = true;
			}
			if ($counter == $total && $row['type'] == 'pagebreak') {
				Display::display_error_message(get_lang('PagebreakNotLast'), false);
				$error = true;
			}
			$counter++;
		}

		if (!$continue && $error) {
			Display::display_footer();
			exit;
		}
	}

	/**
	 * This function removes an (or multiple) answer(s) of a user on a question of a survey
	 *
	 * @param mixed   The user id or email of the person who fills the survey
	 * @param integer The survey id
	 * @param integer The question id
	 * @param integer The option id
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function remove_answer($user, $survey_id, $question_id, $course_id) {
        $course_id = intval($course_id);
		// table definition
		$table_survey_answer 		= Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$sql = "DELETE FROM $table_survey_answer
				WHERE   c_id = $course_id AND
				        user = '".Database::escape_string($user)."'
				AND survey_id = '".Database::escape_string($survey_id)."'
				AND question_id = '".Database::escape_string($question_id)."'";
		Database::query($sql);
	}

	/**
	 * This function stores an answer of a user on a question of a survey
	 *
	 * @param mixed   The user id or email of the person who fills the survey
	 * @param integer Survey id
	 * @param integer Question id
	 * @param integer Option id
	 * @param string  Option value
	 * @param array	  Survey data settings
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function store_answer($user, $survey_id, $question_id, $option_id, $option_value, $survey_data)
    {
		// Table definition
		$table_survey_answer = Database :: get_course_table(TABLE_SURVEY_ANSWER);

		// Make the survey anonymous
		if ($survey_data['anonymous'] == 1) {
			if (!$_SESSION['surveyuser']) {
				$user = md5($user.time());
				$_SESSION['surveyuser'] = $user;
			} else {
				$user = $_SESSION['surveyuser'];
			}
		}
		$course_id = $survey_data['c_id'];

		$sql = "INSERT INTO $table_survey_answer (c_id, user, survey_id, question_id, option_id, value) VALUES (
				$course_id,
				'".Database::escape_string($user)."',
				'".Database::escape_string($survey_id)."',
				'".Database::escape_string($question_id)."',
				'".Database::escape_string($option_id)."',
				'".Database::escape_string($option_value)."'
				)";
		Database::query($sql);
	}

	/**
	 * This function checks the parameters that are used in this page
	 *
	 * @return 	string 	The header, an error and the footer if any parameter fails, else it returns true
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function check_parameters($people_filled)
    {
		$error = false;

		// Getting the survey data
		$survey_data = survey_manager::get_survey($_GET['survey_id']);

		// $_GET['survey_id'] has to be numeric
		if (!is_numeric($_GET['survey_id'])) {
			$error = get_lang('IllegalSurveyId');
		}

		// $_GET['action']
		$allowed_actions = array('overview', 'questionreport', 'userreport', 'comparativereport', 'completereport','deleteuserreport');
		if (isset($_GET['action']) && !in_array($_GET['action'], $allowed_actions)) {
			$error = get_lang('ActionNotAllowed');
		}

		// User report
		if (isset($_GET['action']) && $_GET['action'] == 'userreport') {
			if ($survey_data['anonymous'] == 0) {
				foreach ($people_filled as $key => & $value) {
					$people_filled_userids[] = $value['invited_user'];
				}
			} else {
				$people_filled_userids = $people_filled;
			}

			if (isset($_GET['user']) && !in_array($_GET['user'], $people_filled_userids)) {
				$error = get_lang('UnknowUser');
			}
		}

		// Question report
		if (isset($_GET['action']) && $_GET['action'] == 'questionreport') {
			if (isset($_GET['question']) && !is_numeric($_GET['question'])) {
				$error = get_lang('UnknowQuestion');
			}
		}

		if ($error) {
			$tool_name = get_lang('Reporting');
			Display::display_header($tool_name);
			Display::display_error_message(get_lang('Error').': '.$error, false);
			Display::display_footer();
			exit;
		} else {
			return true;
		}
	}

	/**
	 * This function deals with the action handling
	 * @return	void
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function handle_reporting_actions($people_filled)
    {
        $action = isset($_GET['action']) ? $_GET['action'] : null;

		// Getting the number of question
		$temp_questions_data = survey_manager::get_questions($_GET['survey_id']);

		// Sorting like they should be displayed and removing the non-answer question types (comment and pagebreak)
		$my_temp_questions_data=($temp_questions_data==null) ? array() : $temp_questions_data;
		foreach ($my_temp_questions_data as $key => & $value) {
			if ($value['type'] != 'comment' && $value['type'] != 'pagebreak') {
				$questions_data[$value['sort']] = $value;
			}
		}

		// Counting the number of questions that are relevant for the reporting
		$survey_data['number_of_questions'] = count($questions_data);

		if ($action == 'questionreport') {
			SurveyUtil::display_question_report($survey_data);
		}
		if ($action == 'userreport') {
			SurveyUtil::display_user_report($people_filled, $survey_data);
		}
		if ($action == 'comparativereport') {
			SurveyUtil::display_comparative_report();
		}
		if ($action == 'completereport') {
			SurveyUtil::display_complete_report($survey_data);
		}
		if ($action == 'deleteuserreport') {
			SurveyUtil::delete_user_report($_GET['survey_id'], $_GET['user']);
			//SurveyUtil::display_user_report(); //Could work but looks a bit clunky
		}
	}

	/**
	 * This function deletes the report of an user who wants to retake the survey
	 * @param integer survey_id
	 * @param integer user_id
	 * @return void
	 * @author Christian Fasanando Flores <christian.fasanando@dokeos.com>
	 * @version November 2008
	 */
	function delete_user_report($survey_id, $user_id)
    {
		$table_survey_answer 		= Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_survey 				= Database :: get_course_table(TABLE_SURVEY);

        $course_id = api_get_course_int_id();

		if (!empty($survey_id) && !empty($user_id)) {
			// delete data from survey_answer by user_id and survey_id
			$sql = "DELETE FROM $table_survey_answer WHERE c_id = $course_id AND survey_id = '".(int)$survey_id."' AND user = '".(int)$user_id."'";
			Database::query($sql);
			// update field answered from survey_invitation by user_id and survey_id
			$sql = "UPDATE $table_survey_invitation SET answered = '0' WHERE c_id = $course_id AND survey_code = (SELECT code FROM $table_survey WHERE c_id = $course_id AND survey_id = '".(int)$survey_id."') AND user = '".(int)$user_id."'";
			$result = Database::query($sql);
		}

		if ($result !== false) {
			$message = get_lang('SurveyUserAnswersHaveBeenRemovedSuccessfully').'<br />
					<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action=userreport&survey_id='.Security::remove_XSS($survey_id).'">'.get_lang('GoBack').'</a>';
			Display::display_confirmation_message($message, false);
		}
	}

	/**
	 * This function displays the user report which is basically nothing more than a one-page display of all the questions
	 * of the survey that is filled with the answers of the person who filled the survey.
	 *
	 * @return 	string	html code of the one-page survey with the answers of the selected user
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007 - Updated March 2008
	 */
	static function display_user_report($people_filled, $survey_data)
    {
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);

		// Actions bar
		echo '<div class="actions">';
		echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?survey_id='.Security::remove_XSS($_GET['survey_id']).'">'.Display::return_icon('back.png',get_lang('BackTo').' '.get_lang('ReportingOverview'),'',ICON_SIZE_MEDIUM).'</a>';
		if (isset($_GET['user'])) {
			// The delete link
			echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action=deleteuserreport&amp;survey_id='.Security::remove_XSS($_GET['survey_id']).'&amp;user='.Security::remove_XSS($_GET['user']).'" >'.Display::return_icon('delete.png', get_lang('Delete'),'',ICON_SIZE_MEDIUM).'</a>';

			// Export the user report
			echo '<a href="javascript: void(0);" onclick="document.form1a.submit();">'.Display::return_icon('export_csv.png', get_lang('ExportAsCSV'),'',ICON_SIZE_MEDIUM).'</a> ';
			echo '<a href="javascript: void(0);" onclick="document.form1b.submit();">'.Display::return_icon('export_excel.png', get_lang('ExportAsXLS'),'',ICON_SIZE_MEDIUM).'</a> ';
			echo '<form id="form1a" name="form1a" method="post" action="'.api_get_self().'?action='.Security::remove_XSS($_GET['action']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'&user_id='.Security::remove_XSS($_GET['user']).'">';
			echo '<input type="hidden" name="export_report" value="export_report">';
			echo '<input type="hidden" name="export_format" value="csv">';
			echo '</form>';
			echo '<form id="form1b" name="form1b" method="post" action="'.api_get_self().'?action='.Security::remove_XSS($_GET['action']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'&user_id='.Security::remove_XSS($_GET['user']).'">';
			echo '<input type="hidden" name="export_report" value="export_report">';
			echo '<input type="hidden" name="export_format" value="xls">';
			echo '</form>';
			echo '<form id="form2" name="form2" method="post" action="'.api_get_self().'?action='.Security::remove_XSS($_GET['action']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'">';
		}
		echo '</div>';

		// Step 1: selection of the user
		echo "<script language=\"JavaScript\" type=\"text/javascript\">
		<!--
		function jumpMenu(targ,selObj,restore)
		{
		  eval(targ+\".location='\"+selObj.options[selObj.selectedIndex].value+\"'\");
		  if (restore) selObj.selectedIndex=0;
		}
		//-->
		</script>";
		echo get_lang('SelectUserWhoFilledSurvey').'<br />';
		echo '<select name="user" onchange="jumpMenu(\'parent\',this,0)">';
		echo '<option value="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action='.Security::remove_XSS($_GET['action']).'&amp;survey_id='.Security::remove_XSS($_GET['survey_id']).'">'.get_lang('SelectUser').'</option>';

		foreach ($people_filled as $key => & $person) {
			if ($survey_data['anonymous'] == 0) {
				$name = api_get_person_name($person['firstname'], $person['lastname']);
				$id = $person['user_id'];
				if ($id == '') {
					$id = $person['invited_user'];
					$name = $person['invited_user'];
				}
			} else {
				$name  = $key + 1;
				$id = $person;
			}
			echo '<option value="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action='.Security::remove_XSS($_GET['action']).'&amp;survey_id='.Security::remove_XSS($_GET['survey_id']).'&amp;user='.Security::remove_XSS($id).'" ';
			if ($_GET['user'] == $id) {
				echo 'selected="selected"';
			}
			echo '>'.$name.'</option>';
		}
		echo '</select>';
		$course_id = api_get_course_int_id();
		// Step 2: displaying the survey and the answer of the selected users
		if (isset($_GET['user'])) {
			Display::display_normal_message(get_lang('AllQuestionsOnOnePage'), false);

			// Getting all the questions and options
			$sql = "SELECT
			            survey_question.question_id, survey_question.survey_id, survey_question.survey_question, survey_question.display, survey_question.max_value, survey_question.sort, survey_question.type,
                        survey_question_option.question_option_id, survey_question_option.option_text, survey_question_option.sort as option_sort
					FROM $table_survey_question survey_question
					LEFT JOIN $table_survey_question_option survey_question_option
					ON survey_question.question_id = survey_question_option.question_id AND survey_question_option.c_id = $course_id
					WHERE
					    survey_question.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
                        survey_question.c_id = $course_id
					ORDER BY survey_question.sort, survey_question_option.sort ASC";
			$result = Database::query($sql);
			while ($row = Database::fetch_array($result, 'ASSOC')) {
				if($row['type'] != 'pagebreak') {
					$questions[$row['sort']]['question_id'] 						= $row['question_id'];
					$questions[$row['sort']]['survey_id'] 							= $row['survey_id'];
					$questions[$row['sort']]['survey_question'] 					= $row['survey_question'];
					$questions[$row['sort']]['display'] 							= $row['display'];
					$questions[$row['sort']]['type'] 								= $row['type'];
					$questions[$row['sort']]['maximum_score'] 						= $row['max_value'];
					$questions[$row['sort']]['options'][$row['question_option_id']] = $row['option_text'];
				}
			}

			// Getting all the answers of the user
			$sql = "SELECT * FROM $table_survey_answer
			        WHERE
                        c_id = $course_id AND
                        survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
                        user = '".Database::escape_string($_GET['user'])."'";
			$result = Database::query($sql);
			while ($row = Database::fetch_array($result, 'ASSOC')) {
				$answers[$row['question_id']][] = $row['option_id'];
				$all_answers[$row['question_id']][] = $row;
			}
			// Displaying all the questions
			$second_parameter=array();

			foreach ($questions as $key => & $question) {
				// If the question type is a scoring then we have to format the answers differently
				if ($question['type'] == 'score') {
					if (is_array($question) && is_array($all_answers)) {
						foreach ($all_answers[$question['question_id']] as $key => & $answer_array) {
							$second_parameter[$answer_array['option_id']] = $answer_array['value'];
						}
					}
				} else {
					$second_parameter = $answers[$question['question_id']];
					if ($question['type'] == 'open') {
						$second_parameter = array();
						$second_parameter[] = $all_answers[$question['question_id']][0]['option_id'];
					}
				}
				$ch_type = 'ch_'.$question['type'];
				$display = new $ch_type;
				$display->render_question($question, $second_parameter);
			}
		}
	}

	/**
	 * This function displays the report by question.
	 *
	 * It displays a table with all the options of the question and the number of users who have answered positively on the option.
	 * The number of users who answered positive on a given option is expressed in an absolute number, in a percentage of the total
	 * and graphically using bars
	 * By clicking on the absolute number you get a list with the persons who have answered this.
	 * You can then click on the name of the person and you will then go to the report by user where you see all the
	 * answers of that user.
	 *
	 * @param 	array 	All the survey data
	 * @return 	string	html code that displays the report by question
	 * @todo allow switching between horizontal and vertical.
	 * @todo multiple response: percentage are probably not OK
	 * @todo the question and option text have to be shortened and should expand when the user clicks on it.
	 * @todo the pagebreak and comment question types should not be shown => removed from $survey_data before
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007 - Updated March 2008
	 */
	function display_question_report($survey_data)
    {
	    $course_id = api_get_course_int_id();
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);

		// Determining the offset of the sql statement (the n-th question of the survey)
		if (!isset($_GET['question'])) {
			$offset = 0;
		} else {
			$offset = Database::escape_string($_GET['question']);
		}

		echo '<div class="actions">';
		echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?survey_id='.Security::remove_XSS($_GET['survey_id']).'">'.Display::return_icon('back.png',get_lang('BackTo').' '.get_lang('ReportingOverview'),'',ICON_SIZE_MEDIUM).'</a>';
        echo '</div>';

		if ($survey_data['number_of_questions'] > 0) {
			echo '<div id="question_report_questionnumbers">'.get_lang('GoToQuestion').': ';
			for ($i = 1; $i <= $survey_data['number_of_questions']; $i++) {
				if ($offset != $i - 1) {
					echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action=questionreport&amp;survey_id='.Security::remove_XSS($_GET['survey_id']).'&amp;question='.($i-1).'">'.$i.'</a>';
				} else {
					echo $i;
				}
				if ($i < $survey_data['number_of_questions']) {
					echo ' | ';
				}
			}
			echo '</div>';

			// Getting the question information
			$sql = "SELECT * FROM $table_survey_question
			        WHERE
			            c_id = $course_id AND
                        survey_id='".Database::escape_string($_GET['survey_id'])."' AND
                        type<>'pagebreak' AND type<>'comment'
                    ORDER BY sort ASC
                    LIMIT ".$offset.",1";
			$result = Database::query($sql);
			$question = Database::fetch_array($result);

			// Navigate through the questions (next and previous)
			if ($_GET['question'] != 0) {
				echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action='.Security::remove_XSS($_GET['action']).'&amp;survey_id='.$_GET['survey_id'].'&amp;question='.Security::remove_XSS($offset-1).'">'.Display::return_icon('action_prev.png', get_lang('PreviousQuestion'), array('align' => 'middle')).' '.get_lang('PreviousQuestion').'</a>  ';
			} else {
				echo Display::return_icon('action_prev.png', get_lang('PreviousQuestion'), array('align' => 'middle')).' '.get_lang('PreviousQuestion').' ';
			}
			echo ' | ';
			if ($_GET['question'] < ($survey_data['number_of_questions'] - 1)) {
				echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action='.Security::remove_XSS($_GET['action']).'&amp;survey_id='.Security::remove_XSS($_GET['survey_id']).'&amp;question='.Security::remove_XSS($offset+1).'">'.get_lang('NextQuestion').' '.Display::return_icon('action_next.png', get_lang('NextQuestion'), array('align' => 'middle')).'</a>';
			} else {
				echo get_lang('NextQuestion').' '.Display::return_icon('action_next.png', get_lang('NextQuestion'), array('align' => 'middle'));
			}
		}

		echo $question['survey_question'];

		if ($question['type'] == 'score') {
			/** @todo This function should return the options as this is needed further in the code */
			$options = SurveyUtil::display_question_report_score($survey_data, $question, $offset);
		} elseif ($question['type'] == 'open') {
			/** @todo Also get the user who has answered this */
			$sql = "SELECT * FROM $table_survey_answer
                    WHERE
                        c_id = $course_id AND
                        survey_id='".Database::escape_string($_GET['survey_id'])."' AND
                        question_id = '".Database::escape_string($question['question_id'])."'";
			$result = Database::query($sql);
			while ($row = Database::fetch_array($result)) {
				echo $row['option_id'].'<hr noshade="noshade" size="1" />';
			}
		} else {
			// Getting the options
			$sql = "SELECT * FROM $table_survey_question_option
                    WHERE
                        c_id = $course_id AND survey_id='".Database::escape_string($_GET['survey_id'])."' AND
                        question_id = '".Database::escape_string($question['question_id'])."'
                    ORDER BY sort ASC";
			$result = Database::query($sql);
			while ($row = Database::fetch_array($result)) {
				$options[$row['question_option_id']] = $row;
			}
			// Getting the answers
			$sql = "SELECT *, count(answer_id) as total FROM $table_survey_answer
						WHERE c_id = $course_id AND
						      survey_id='".Database::escape_string($_GET['survey_id'])."' AND
						      question_id = '".Database::escape_string($question['question_id'])."'
						GROUP BY option_id, value";
			$result = Database::query($sql);
			while ($row = Database::fetch_array($result)) {
				$number_of_answers += $row['total'];
				$data[$row['option_id']] = $row;
			}


			// displaying the table: headers
			echo '<table class="data_table">';
			echo '	<tr>';
			echo '		<th>&nbsp;</th>';
			echo '		<th>'.get_lang('AbsoluteTotal').'</th>';
			echo '		<th>'.get_lang('Percentage').'</th>';
			echo '		<th>'.get_lang('VisualRepresentation').'</th>';
			echo '	<tr>';

			// Displaying the table: the content
			if (is_array($options)) {
				foreach ($options as $key => & $value) {
					$absolute_number = $data[$value['question_option_id']]['total'];
                    if ($question['type'] == 'percentage' && empty($absolute_number)) {
                        continue;
                    }
					if ($number_of_answers == 0) {
						$answers_number = 0;
					} else {
						$answers_number = $absolute_number/$number_of_answers*100;
					}
					echo '	<tr>';
					echo '		<td>'.$value['option_text'].'</td>';
					echo '		<td align="right"><a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action='.Security::remove_XSS($_GET['action']).'&amp;survey_id='.Security::remove_XSS($_GET['survey_id']).'&amp;question='.Security::remove_XSS($offset).'&amp;viewoption='.$value['question_option_id'].'">'.$absolute_number.'</a></td>';
					echo '		<td align="right">'.round($answers_number, 2).' %</td>';
					echo '		<td align="right">';
					$size = $answers_number*2;
					if ($size > 0) {
						echo '<div style="border:1px solid #264269; background-color:#aecaf4; height:10px; width:'.$size.'px">&nbsp;</div>';
					}
					echo '		</td>';
					echo '	</tr>';
				}
			}
			// displaying the table: footer (totals)
			echo '	<tr>';
			echo '		<td style="border-top:1px solid black;"><b>'.get_lang('Total').'</b></td>';
			echo '		<td style="border-top:1px solid black;" align="right"><b>'.($number_of_answers==0?'0':$number_of_answers).'</b></td>';
			echo '		<td style="border-top:1px solid black;">&nbsp;</td>';
			echo '		<td style="border-top:1px solid black;">&nbsp;</td>';
			echo '	</tr>';

			echo '</table>';
		}

		if (isset($_GET['viewoption'])) {
			echo get_lang('PeopleWhoAnswered').': '.$options[Security::remove_XSS($_GET['viewoption'])]['option_text'].'<br />';

			if (is_numeric($_GET['value'])) {
				$sql_restriction = "AND value='".Database::escape_string($_GET['value'])."'";
			}

			$sql = "SELECT user FROM $table_survey_answer WHERE c_id = $course_id AND option_id = '".Database::escape_string($_GET['viewoption'])."' $sql_restriction";
			$result = Database::query($sql);
			while ($row = Database::fetch_array($result)) {
			    $user_info = api_get_user_info($row['user']);
				echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action=userreport&survey_id='.Security::remove_XSS($_GET['survey_id']).'&user='.$row['user'].'">'.$user_info['complete_name'].'</a><br />';
			}
		}
	}

	/**
	 * Display score data about a survey question
	 * @param	array	Question info
	 * @param	integer	The offset of results shown
	 * @return	void 	(direct output)
	 */
	function display_question_report_score($survey_data, $question, $offset)
    {
	    $course_id = api_get_course_int_id();
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);

        $course_id = api_get_course_int_id();

		// Getting the options
		$sql = "SELECT * FROM $table_survey_question_option
                WHERE
                    c_id = $course_id AND
                    survey_id='".Database::escape_string($_GET['survey_id'])."' AND
                    question_id = '".Database::escape_string($question['question_id'])."'
                ORDER BY sort ASC";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			$options[$row['question_option_id']] = $row;
		}

		// Getting the answers
		$sql = "SELECT *, count(answer_id) as total FROM $table_survey_answer
                WHERE
                   c_id = $course_id AND
                   survey_id='".Database::escape_string($_GET['survey_id'])."' AND
                   question_id = '".Database::escape_string($question['question_id'])."'
                GROUP BY option_id, value";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			$number_of_answers += $row['total'];
			$data[$row['option_id']][$row['value']] = $row;
		}
		// Displaying the table: headers
		echo '<table class="data_table">';
		echo '	<tr>';
		echo '		<th>&nbsp;</th>';
		echo '		<th>'.get_lang('Score').'</th>';
		echo '		<th>'.get_lang('AbsoluteTotal').'</th>';
		echo '		<th>'.get_lang('Percentage').'</th>';
		echo '		<th>'.get_lang('VisualRepresentation').'</th>';
		echo '	<tr>';
		// Displaying the table: the content
		foreach ($options as $key => & $value) {
			for ($i = 1; $i <= $question['max_value']; $i++) {
				$absolute_number = $data[$value['question_option_id']][$i]['total'];
				echo '	<tr>';
				echo '		<td>'.$value['option_text'].'</td>';
				echo '		<td>'.$i.'</td>';
				echo '		<td><a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?action='.Security::remove_XSS($_GET['action']).'&amp;survey_id='.Security::remove_XSS($_GET['survey_id']).'&amp;question='.Security::remove_XSS($offset).'&amp;viewoption='.$value['question_option_id'].'&amp;value='.$i.'">'.$absolute_number.'</a></td>';
				echo '		<td>'.round($absolute_number/$number_of_answers*100, 2).' %</td>';
				echo '		<td>';
				$size = ($absolute_number/$number_of_answers*100*2);
				if ($size > 0) {
					echo '			<div style="border:1px solid #264269; background-color:#aecaf4; height:10px; width:'.$size.'px">&nbsp;</div>';
				}
				echo '		</td>';
				echo '	</tr>';
			}
		}
		// Displaying the table: footer (totals)
		echo '	<tr>';
		echo '		<td style="border-top:1px solid black"><b>'.get_lang('Total').'</b></td>';
		echo '		<td style="border-top:1px solid black">&nbsp;</td>';
		echo '		<td style="border-top:1px solid black"><b>'.$number_of_answers.'</b></td>';
		echo '		<td style="border-top:1px solid black">&nbsp;</td>';
		echo '		<td style="border-top:1px solid black">&nbsp;</td>';
		echo '	</tr>';

		echo '</table>';
	}

	/**
	 * This functions displays the complete reporting
	 * @return	string	HTML code
	 * @todo open questions are not in the complete report yet.
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function display_complete_report($survey_data)
    {
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);

		// Actions bar
		echo '<div class="actions">';
		echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?survey_id='.Security::remove_XSS($_GET['survey_id']).'">
		'.Display::return_icon('back.png',get_lang('BackTo').' '.get_lang('ReportingOverview'),'',ICON_SIZE_MEDIUM).'</a>';
		echo '<a class="survey_export_link" href="javascript: void(0);" onclick="document.form1a.submit();">
		'.Display::return_icon('export_csv.png',get_lang('ExportAsCSV'),'',ICON_SIZE_MEDIUM).'</a>';
		echo '<a class="survey_export_link" href="javascript: void(0);" onclick="document.form1b.submit();">
		'.Display::return_icon('export_excel.png',get_lang('ExportAsXLS'),'',ICON_SIZE_MEDIUM).'</a>';
		echo '</div>';

		// The form
		echo '<form id="form1a" name="form1a" method="post" action="'.api_get_self().'?action='.Security::remove_XSS($_GET['action']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'">';
		echo '<input type="hidden" name="export_report" value="export_report">';
		echo '<input type="hidden" name="export_format" value="csv">';
		echo '</form>';
		echo '<form id="form1b" name="form1b" method="post" action="'.api_get_self().'?action='.Security::remove_XSS($_GET['action']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'">';
		echo '<input type="hidden" name="export_report" value="export_report">';
		echo '<input type="hidden" name="export_format" value="xls">';
		echo '</form>';

		echo '<form id="form2" name="form2" method="post" action="'.api_get_self().'?action='.Security::remove_XSS($_GET['action']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'">';

		// The table
		echo '<br /><table class="data_table" border="1">';
		// Getting the number of options per question
		echo '	<tr>';
		echo '		<th>';
		if ($_POST['submit_question_filter'] || $_POST['export_report']) {
			echo '<button class="cancel" type="submit" name="reset_question_filter" value="'.get_lang('ResetQuestionFilter').'">'.get_lang('ResetQuestionFilter').'</button>';
		}
		echo '<button class="save" type="submit" name="submit_question_filter" value="'.get_lang('SubmitQuestionFilter').'">'.get_lang('SubmitQuestionFilter').'</button>';
		echo '</th>';

		$display_extra_user_fields = false;
		if (!($_POST['submit_question_filter'] || $_POST['export_report']) || !empty($_POST['fields_filter'])) {
			// Show user fields section with a big th colspan that spans over all fields
			$extra_user_fields = UserManager::get_extra_fields(0, 0, 5, 'ASC', false, true);
			$num = count($extra_user_fields);
			if ($num > 0 ) {
				echo '<th '.($num>0?' colspan="'.$num.'"':'').'>';
				echo '<label><input type="checkbox" name="fields_filter" value="1" checked="checked"/> ';
				echo get_lang('UserFields');
				echo '</label>';
				echo '</th>';
				$display_extra_user_fields = true;
			}
		}

		$course_id = api_get_course_int_id();


		// Get all the questions ordered by the "sort" column
		// <hub> modify the query to display open questions too
		//		$sql = "SELECT q.question_id, q.type, q.survey_question, count(o.question_option_id) as number_of_options
		//				FROM $table_survey_question q LEFT JOIN $table_survey_question_option o
		//				ON q.question_id = o.question_id
		//				WHERE q.question_id = o.question_id
		//				AND q.survey_id = '".Database::escape_string($_GET['survey_id'])."'
		//				GROUP BY q.question_id
		//				ORDER BY q.sort ASC";
		$sql = "SELECT q.question_id, q.type, q.survey_question, count(o.question_option_id) as number_of_options
				FROM $table_survey_question q LEFT JOIN $table_survey_question_option o
				ON q.question_id = o.question_id
				WHERE q.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
				q.c_id = $course_id AND
				o.c_id = $course_id
				GROUP BY q.question_id
				ORDER BY q.sort ASC";
		// </hub>
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			// We show the questions if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			//if (!($_POST['submit_question_filter'] || $_POST['export_report']) || in_array($row['question_id'], $_POST['questions_filter'])) {
			if (!($_POST['submit_question_filter']) || (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter']))) {
				// We do not show comment and pagebreak question types
				if ($row['type'] != 'comment' && $row['type'] != 'pagebreak') {
					echo '		<th';
					// <hub> modified tst to include percentage
					if ($row['number_of_options'] > 0 && $row['type'] != 'percentage') {
					// </hub>
						echo ' colspan="'.$row['number_of_options'].'"';
					}
					echo '>';

					echo '<label><input type="checkbox" name="questions_filter[]" value="'.$row['question_id'].'" checked="checked"/> ';
					echo $row['survey_question'];
					echo '</label>';
					echo '</th>';
				}
				// No column at all if it's not a question
			}
			$questions[$row['question_id']] = $row;
		}
		echo '	</tr>';
		// Getting all the questions and options
		echo '	<tr>';
		echo '		<th>&nbsp;</th>'; // the user column

		if (!($_POST['submit_question_filter'] || $_POST['export_report']) || !empty($_POST['fields_filter'])) {
			//show the fields names for user fields
			foreach($extra_user_fields as & $field) {
				echo '<th>'.$field[3].'</th>';
			}
		}

		// cells with option (none for open question)
		$sql = "SELECT 	sq.question_id, sq.survey_id,
						sq.survey_question, sq.display,
						sq.sort, sq.type, sqo.question_option_id,
						sqo.option_text, sqo.sort as option_sort
				FROM $table_survey_question sq
				LEFT JOIN $table_survey_question_option sqo
				ON sq.question_id = sqo.question_id
				WHERE
				    sq.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
                    sq.c_id = $course_id AND
                    sqo.c_id = $course_id
				ORDER BY sq.sort ASC, sqo.sort ASC";
		$result = Database::query($sql);

		$display_percentage_header = 1;	// in order to display only once the cell option (and not 100 times)
		while ($row = Database::fetch_array($result)) {
			// We show the options if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a question filter but the question is selected for display
			//if (!($_POST['submit_question_filter'] || $_POST['export_report']) || in_array($row['question_id'], $_POST['questions_filter'])) {
			if (!($_POST['submit_question_filter']) || (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter']))) {
				// <hub> modif 05-05-2010
				// we do not show comment and pagebreak question types
				if ($row['type'] == 'open') {
					echo '<th>&nbsp;-&nbsp;</th>';
					$possible_answers[$row['question_id']][$row['question_option_id']] = $row['question_option_id'];
					$display_percentage_header = 1;
				} else if ($row['type'] == 'percentage' && $display_percentage_header) {
					echo '<th>&nbsp;%&nbsp;</th>';
					$possible_answers[$row['question_id']][$row['question_option_id']] = $row['question_option_id'];
					$display_percentage_header = 0;
				} else if ($row['type'] == 'percentage') {
					$possible_answers[$row['question_id']][$row['question_option_id']] = $row['question_option_id'];
				} else if ($row['type'] <> 'comment' AND $row['type'] <> 'pagebreak' AND $row['type'] <> 'percentage') {
					echo '<th>';
					echo $row['option_text'];
					echo '</th>';
					$possible_answers[$row['question_id']][$row['question_option_id']] = $row['question_option_id'];
					$display_percentage_header = 1;
				}
				//no column at all if the question was not a question
				// </hub>
			}
		}

		echo '	</tr>';

		// Getting all the answers of the users
		$old_user = '';
		$answers_of_user = array();
		$sql = "SELECT * FROM $table_survey_answer WHERE c_id = $course_id AND survey_id='".Database::escape_string($_GET['survey_id'])."' ORDER BY user ASC";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			if ($old_user != $row['user'] && $old_user != '') {
				SurveyUtil::display_complete_report_row($survey_data, $possible_answers, $answers_of_user, $old_user, $questions, $display_extra_user_fields);
				$answers_of_user=array();
			}
			if ($questions[$row['question_id']]['type'] != 'open') {
				$answers_of_user[$row['question_id']][$row['option_id']] = $row;
			} else {
				$answers_of_user[$row['question_id']][0] = $row;
			}
			$old_user = $row['user'];
		}
		SurveyUtil::display_complete_report_row($survey_data, $possible_answers, $answers_of_user, $old_user, $questions, $display_extra_user_fields);
		// This is to display the last user
		echo '</table>';
		echo '</form>';
	}

	/**
	 * This function displays a row (= a user and his/her answers) in the table of the complete report.
	 *
     * @param array $survey_data
	 * @param 	array	Possible options
	 * @param 	array 	User answers
	 * @param	mixed	User ID or user details string
	 * @param	boolean	Whether to show extra user fields or not
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007 - Updated March 2008
	 */
	static function display_complete_report_row($survey_data, $possible_options, $answers_of_user, $user, $questions, $display_extra_user_fields = false)
    {
        $user = Security::remove_XSS($user);
		echo '<tr>';
		if ($survey_data['anonymous'] == 0) {
			if (intval($user) !== 0) {
				$sql = 'SELECT firstname, lastname FROM '.Database::get_main_table(TABLE_MAIN_USER).' WHERE user_id='.intval($user);
				$rs = Database::query($sql);
				if ($row = Database::fetch_array($rs)) {
					$user_displayed = api_get_person_name($row['firstname'], $row['lastname']);
				} else {
					$user_displayed = '-';
				}
				echo '<th><a href="'.api_get_self().'?action=userreport&survey_id='.Security::remove_XSS($_GET['survey_id']).'&user='.$user.'">'.$user_displayed.'</a></th>'; // the user column
			} else {
				echo '<th>'.$user.'</th>'; // the user column
			}
		} else {
			echo '<th>' . get_lang('Anonymous') . '</th>';
		}

		if ($display_extra_user_fields) {
			// Show user fields data, if any, for this user
			$user_fields_values = UserManager::get_extra_user_data(intval($user), false, false, false, true);
			foreach ($user_fields_values as & $value) {
				echo '<td align="center">'.$value.'</td>';
			}
		}
		if (is_array($possible_options)) {
			// <hub> modified to display open answers and percentage
			foreach ($possible_options as $question_id => & $possible_option) {
				if ($questions[$question_id]['type'] == 'open') {
					echo '<td align="center">';
					echo $answers_of_user[$question_id]['0']['option_id'];
					echo '</td>';
				} else {
					foreach ($possible_option as $option_id => & $value) {
						if ($questions[$question_id]['type'] == 'percentage') {
							if (!empty($answers_of_user[$question_id][$option_id])) {
								echo "<td align='center'>";
								echo $answers_of_user[$question_id][$option_id]['value'];
								echo "</td>";
							}
						}
						else {
							echo '<td align="center">';
							if (!empty($answers_of_user[$question_id][$option_id])) {
								if ($answers_of_user[$question_id][$option_id]['value'] != 0) {
									echo $answers_of_user[$question_id][$option_id]['value'];
								}
								else {
									echo 'v';
								}
							}
						} // </hub>
					}
				}
			}
		}
		echo '</tr>';
	}

	/**
	 * Quite similar to display_complete_report(), returns an HTML string
	 * that can be used in a csv file
	 * @todo consider merging this function with display_complete_report
	 * @return	string	The contents of a csv file
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function export_complete_report($survey_data, $user_id = 0)
    {

		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);

		// The first column
		$return = ';';

		// Show extra fields blank space (enough for extra fields on next line)

        $extra_user_fields = UserManager::get_extra_fields(0, 0, 5, 'ASC', false, true);

        $num = count($extra_user_fields);
        $return .= str_repeat(';', $num);

		$course_id = api_get_course_int_id();

		$sql = "SELECT questions.question_id, questions.type, questions.survey_question, count(options.question_option_id) as number_of_options
				FROM $table_survey_question questions
                LEFT JOIN $table_survey_question_option options
				ON questions.question_id = options.question_id  AND options.c_id = $course_id
				WHERE
				    questions.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
                    questions.c_id = $course_id
				GROUP BY questions.question_id
				ORDER BY questions.sort ASC";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			// We show the questions if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) || (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter']))) {
				// We do not show comment and pagebreak question types
				if ($row['type'] != 'comment' && $row['type'] != 'pagebreak') {
					if ($row['number_of_options'] == 0 && $row['type'] == 'open') {
						$return .= str_replace("\r\n",'  ', api_html_entity_decode(strip_tags($row['survey_question']), ENT_QUOTES)).';';
					} else {
						for ($ii = 0; $ii < $row['number_of_options']; $ii++) {
							$return .= str_replace("\r\n",'  ', api_html_entity_decode(strip_tags($row['survey_question']), ENT_QUOTES)).';';
						}
					}
				}
			}
		}
		$return .= "\n";

		// Getting all the questions and options
		$return .= ';';

		// Show extra field values
		//if (!($_POST['submit_question_filter'] || $_POST['export_report']) || !empty($_POST['fields_filter'])) {
			// Show the fields names for user fields
			if (!empty($extra_user_fields)) {
				foreach ($extra_user_fields as & $field) {
					$return .= '"'.str_replace("\r\n",'  ',api_html_entity_decode(strip_tags($field[3]), ENT_QUOTES)).'";';
				}
			}
		//}

		$sql = "SELECT
		            survey_question.question_id, survey_question.survey_id, survey_question.survey_question, survey_question.display, survey_question.sort, survey_question.type,
                    survey_question_option.question_option_id, survey_question_option.option_text, survey_question_option.sort as option_sort
				FROM $table_survey_question survey_question
				LEFT JOIN $table_survey_question_option survey_question_option
				ON survey_question.question_id = survey_question_option.question_id AND survey_question_option.c_id = $course_id
				WHERE
				    survey_question.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
				    survey_question.c_id = $course_id
				ORDER BY survey_question.sort ASC, survey_question_option.sort ASC";
		$result = Database::query($sql);
		$possible_answers = array();
		$possible_answers_type = array();
		while ($row = Database::fetch_array($result)) {
			// We show the options if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) || (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter']))) {
				// We do not show comment and pagebreak question types
				if ($row['type'] != 'comment' && $row['type'] != 'pagebreak') {
					$row['option_text'] = str_replace(array("\r","\n"),array('',''),$row['option_text']);
					$return .= api_html_entity_decode(strip_tags($row['option_text']), ENT_QUOTES).';';
					$possible_answers[$row['question_id']][$row['question_option_id']] = $row['question_option_id'];
					$possible_answers_type[$row['question_id']] = $row['type'];
				}
			}
		}
		$return .= "\n";

		// Getting all the answers of the users
		$old_user = '';
		$answers_of_user = array();
		$sql = "SELECT * FROM $table_survey_answer
		        WHERE c_id = $course_id AND survey_id='".Database::escape_string($_GET['survey_id'])."'";
		if ($user_id != 0) {
			$sql .= "AND user='".Database::escape_string($user_id)."' ";
		}
		$sql .= "ORDER BY user ASC";

		$open_question_iterator = 1;
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			if ($old_user != $row['user'] && $old_user != '') {
				$return .= SurveyUtil::export_complete_report_row($survey_data, $possible_answers, $answers_of_user, $old_user, true);
				$answers_of_user=array();
			}
			if($possible_answers_type[$row['question_id']] == 'open') {
				$temp_id = 'open'.$open_question_iterator;
				$answers_of_user[$row['question_id']][$temp_id] = $row;
				$open_question_iterator++;
			} else {
				$answers_of_user[$row['question_id']][$row['option_id']] = $row;
			}
			$old_user = $row['user'];
		}
		$return .= SurveyUtil::export_complete_report_row($survey_data, $possible_answers, $answers_of_user, $old_user, true); // This is to display the last user
		return $return;
	}

	/**
	 * Add a line to the csv file
	 *
	 * @param	array	Possible answers
	 * @param	array	User's answers
	 * @param 	mixed	User ID or user details as string - Used as a string in the result string
	 * @param	boolean	Whether to display user fields or not
	 * @return	string	One line of the csv file
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function export_complete_report_row($survey_data, $possible_options, $answers_of_user, $user, $display_extra_user_fields = false)
    {
		$return = '';
		if ($survey_data['anonymous'] == 0) {
			if (intval($user) !== 0) {
				$sql = 'SELECT firstname, lastname FROM '.Database::get_main_table(TABLE_MAIN_USER).' WHERE user_id='.intval($user);
				$rs = Database::query($sql);
				if ($row = Database::fetch_array($rs)) {
					$user_displayed = api_get_person_name($row['firstname'], $row['lastname']);
				} else {
					$user_displayed = '-';
				}
				$return .= $user_displayed.';';
			} else {
				$return .= $user.';';
			}
		} else {
			$return .= '-;'; // The user column
		}

		if ($display_extra_user_fields) {
			// Show user fields data, if any, for this user
			$user_fields_values = UserManager::get_extra_user_data($user,false,false, false, true);
			foreach ($user_fields_values as & $value) {
				$return .= '"'.str_replace('"', '""', api_html_entity_decode(strip_tags($value), ENT_QUOTES)).'";';
			}
		}

		if (is_array($possible_options)) {
			foreach ($possible_options as $question_id => $possible_option) {
				if (is_array($possible_option) && count($possible_option) > 0) {
					foreach ($possible_option as $option_id => & $value) {
						$my_answer_of_user = ($answers_of_user[$question_id] == null) ? array() : $answers_of_user[$question_id];
						$key = array_keys($my_answer_of_user);
						if (substr($key[0], 0, 4) == 'open') {
							$return .= '"'.str_replace('"', '""', api_html_entity_decode(strip_tags($answers_of_user[$question_id][$key[0]]['option_id']), ENT_QUOTES)).'"';
						} elseif (!empty($answers_of_user[$question_id][$option_id])) {
							//$return .= 'v';
							if ($answers_of_user[$question_id][$option_id]['value'] != 0) {
								$return .= $answers_of_user[$question_id][$option_id]['value'];
							} else {
								$return .= 'v';
							}
						}
						$return .= ';';
					}
				}
			}
		}
		$return .= "\n";
		return $return;
	}

	/**
	 * Quite similar to display_complete_report(), returns an HTML string
	 * that can be used in a csv file
	 * @todo consider merging this function with display_complete_report
	 * @return	string	The contents of a csv file
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function export_complete_report_xls($survey_data, $filename, $user_id = 0)
    {
		require_once api_get_path(LIBRARY_PATH).'pear/Spreadsheet_Excel_Writer/Writer.php';
		$workbook = new Spreadsheet_Excel_Writer();
		$workbook ->setTempDir(api_get_path(SYS_ARCHIVE_PATH));
		$workbook->send($filename);
		$workbook->setVersion(8); // BIFF8
		$worksheet =& $workbook->addWorksheet('Report 1');
		$worksheet->setInputEncoding(api_get_system_encoding());
		$line = 0;
		$column = 1; // Skip the first column (row titles)

		// Show extra fields blank space (enough for extra fields on next line)
		$display_extra_user_fields = false;
		//if (!empty($_REQUEST['fields_filter'])) {
			// Show user fields section with a big th colspan that spans over all fields
			$extra_user_fields = UserManager::get_extra_fields(0, 0, 5, 'ASC', false, true);
			$num = count($extra_user_fields);
			for ($i = 0; $i < $num; $i++) {
				$worksheet->write($line, $column, '');
				$column++;
			}
			$display_extra_user_fields = true;
		//}

		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);

		$course_id = api_get_course_int_id();

		// First line (questions)
		$sql = "SELECT questions.question_id, questions.type, questions.survey_question, count(options.question_option_id) as number_of_options
				FROM $table_survey_question questions
				LEFT JOIN $table_survey_question_option options
				     ON questions.question_id = options.question_id AND options.c_id = $course_id
				WHERE
				    questions.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
				    questions.c_id = $course_id
				GROUP BY questions.question_id
				ORDER BY questions.sort ASC";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			// We show the questions if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) || (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter']))) {
				// We do not show comment and pagebreak question types
				if ($row['type'] != 'comment' && $row['type'] != 'pagebreak') {
					if ($row['number_of_options'] == 0 && $row['type'] == 'open') {
						$worksheet->write($line,$column,api_html_entity_decode(strip_tags($row['survey_question']), ENT_QUOTES));
						$column ++;
					} else {
						for ($ii = 0; $ii < $row['number_of_options']; $ii ++) {
							$worksheet->write($line, $column, api_html_entity_decode(strip_tags($row['survey_question']), ENT_QUOTES));
							$column ++;
						}
					}
				}
			}
		}
		$line++;
		$column = 1;

		// Show extra field values
		if ($display_extra_user_fields) {
			// Show the fields names for user fields
			foreach ($extra_user_fields as & $field) {
				$worksheet->write($line, $column, api_html_entity_decode(strip_tags($field[3]), ENT_QUOTES));
				$column++;
			}
		}

		// Getting all the questions and options (second line)
		$sql = "SELECT 	survey_question.question_id, survey_question.survey_id, survey_question.survey_question, survey_question.display, survey_question.sort, survey_question.type,
						survey_question_option.question_option_id, survey_question_option.option_text, survey_question_option.sort as option_sort
				FROM $table_survey_question survey_question
				LEFT JOIN $table_survey_question_option survey_question_option
				ON survey_question.question_id = survey_question_option.question_id AND survey_question_option.c_id = $course_id
				WHERE survey_question.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
				survey_question.c_id = $course_id
				ORDER BY survey_question.sort ASC, survey_question_option.sort ASC";
		$result = Database::query($sql);
		$possible_answers = array();
		$possible_answers_type = array();
		while ($row = Database::fetch_array($result)) {
			// We show the options if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) || (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter']))) {
				// We do not show comment and pagebreak question types
				if ($row['type'] != 'comment' && $row['type'] != 'pagebreak') {
					$worksheet->write($line,$column,api_html_entity_decode(strip_tags($row['option_text']), ENT_QUOTES));
					$possible_answers[$row['question_id']][$row['question_option_id']] = $row['question_option_id'];
					$possible_answers_type[$row['question_id']] = $row['type'];
					$column++;
				}
			}
		}

		// Getting all the answers of the users
		$line ++;
		$column = 0;
		$old_user = '';
		$answers_of_user = array();
		$sql = "SELECT * FROM $table_survey_answer WHERE c_id = $course_id AND survey_id='".Database::escape_string($_GET['survey_id'])."' ";
		if ($user_id != 0) {
			$sql .= "AND user='".Database::escape_string($user_id)."' ";
		}
		$sql .=	"ORDER BY user ASC";

		$open_question_iterator = 1;
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			if ($old_user != $row['user'] && $old_user != '') {
				$return = SurveyUtil::export_complete_report_row_xls($survey_data, $possible_answers, $answers_of_user, $old_user, true);
				foreach ($return as $elem) {
					$worksheet->write($line, $column, $elem);
					$column++;
				}
				$answers_of_user = array();
				$line++;
				$column = 0;
			}
			if ($possible_answers_type[$row['question_id']] == 'open') {
				$temp_id = 'open'.$open_question_iterator;
				$answers_of_user[$row['question_id']][$temp_id] = $row;
				$open_question_iterator++;
			} else {
				$answers_of_user[$row['question_id']][$row['option_id']] = $row;
			}
			$old_user = $row['user'];
		}
		$return = SurveyUtil::export_complete_report_row_xls($survey_data, $possible_answers, $answers_of_user, $old_user, true); // this is to display the last user
		foreach ($return as $elem) {
			$worksheet->write($line, $column, $elem);
			$column++;
		}
		$workbook->close();
		return null;
	}

	/**
	 * Add a line to the csv file
	 *
	 * @param	array	Possible answers
	 * @param	array	User's answers
	 * @param 	mixed	User ID or user details as string - Used as a string in the result string
	 * @param	boolean	Whether to display user fields or not
	 * @return	string	One line of the csv file
	 */
	static function export_complete_report_row_xls($survey_data, $possible_options, $answers_of_user, $user, $display_extra_user_fields = false)
    {
		$return = array();
		if ($survey_data['anonymous'] == 0) {
			if (intval($user) !== 0) {
				$sql = 'SELECT firstname, lastname FROM '.Database::get_main_table(TABLE_MAIN_USER).' WHERE user_id='.intval($user);
				$rs = Database::query($sql);
				if($row = Database::fetch_array($rs)) {
					$user_displayed = api_get_person_name($row['firstname'], $row['lastname']);
				} else {
					$user_displayed = '-';
				}
				//echo '		<th><a href="'.api_get_self().'?action=userreport&survey_id='.Security::remove_XSS($_GET['survey_id']).'&user='.$user.'">'.$user_displayed.'</a></th>'; // the user column
				$return[] = $user_displayed;
			} else {
				//echo '		<th>'.$user.'</th>'; // The user column
				$return[] = $user;
			}
		} else {
			$return[] = '-'; // The user column
		}

		if ($display_extra_user_fields) {
			//show user fields data, if any, for this user
			$user_fields_values = UserManager::get_extra_user_data(intval($user),false,false, false, true);
			foreach($user_fields_values as $value) {
				$return[] = api_html_entity_decode(strip_tags($value), ENT_QUOTES);
			}
		}

		if (is_array($possible_options)) {
			foreach ($possible_options as $question_id => & $possible_option) {
				if (is_array($possible_option) && count($possible_option) > 0) {
					foreach ($possible_option as $option_id => & $value) {
						$my_answers_of_user = ($answers_of_user[$question_id]==null) ? array() : $answers_of_user[$question_id];
						$key = array_keys($my_answers_of_user);
						if (substr($key[0], 0, 4) == 'open') {
							$return[] = api_html_entity_decode(strip_tags($answers_of_user[$question_id][$key[0]]['option_id']), ENT_QUOTES);
						} elseif (!empty($answers_of_user[$question_id][$option_id])) {
							//$return .= 'v';
							if ($answers_of_user[$question_id][$option_id]['value'] != 0) {
								$return[] = $answers_of_user[$question_id][$option_id]['value'];
							} else {
								$return[] = 'v';
							}
						} else {
							$return[] = '';
						}
					}
				}
			}
		}
		return $return;
	}

	/**
	 * This function displays the comparative report which allows you to compare two questions
	 * A comparative report creates a table where one question is on the x axis and a second question is on the y axis.
	 * In the intersection is the number of people who have answerd positive on both options.
	 *
	 * @return	string	HTML code
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function display_comparative_report() {
		// Allowed question types for comparative report
		$allowed_question_types = array('yesno', 'multiplechoice', 'multipleresponse', 'dropdown', 'percentage', 'score');

		// Getting all the questions
		$questions = survey_manager::get_questions($_GET['survey_id']);

		// Actions bar
		echo '<div class="actions">';
		echo '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?survey_id='.Security::remove_XSS($_GET['survey_id']).'">'.Display::return_icon('back.png', get_lang('BackTo').' '.get_lang('ReportingOverview'),'',ICON_SIZE_MEDIUM).'</a>';
		echo '</div>';

		// Displaying an information message that only the questions with predefined answers can be used in a comparative report
		Display::display_normal_message(get_lang('OnlyQuestionsWithPredefinedAnswers'), false);

		// The form for selecting the axis of the table
		echo '<form id="form1" name="form1" method="get" action="'.api_get_self().'?action='.Security::remove_XSS($_GET['action']).'&survey_id='.Security::remove_XSS($_GET['survey_id']).'&xaxis='.Security::remove_XSS($_GET['xaxis']).'&y='.Security::remove_XSS($_GET['yaxis']).'">';
		// Survey_id
		echo '<input type="hidden" name="action" value="'.Security::remove_XSS($_GET['action']).'"/>';
		echo '<input type="hidden" name="survey_id" value="'.Security::remove_XSS($_GET['survey_id']).'"/>';
		// X axis
		echo get_lang('SelectXAxis').': ';
		echo '<select name="xaxis">';
		echo '<option value="">---</option>';
		foreach ($questions as $key => & $question) {
			if (is_array($allowed_question_types)) {
				if (in_array($question['type'], $allowed_question_types)) {
					echo '<option value="'.$question['question_id'].'"';
					if ($_GET['xaxis'] == $question['question_id']) {
						echo ' selected="selected"';
					}
					echo '">'.api_substr(strip_tags($question['question']), 0, 50).'</option>';
				}
			}

		}
		echo '</select><br /><br />';
		// Y axis
		echo get_lang('SelectYAxis').': ';
		echo '<select name="yaxis">';
		echo '<option value="">---</option>';
		foreach ($questions as $key => & $question) {
			if (in_array($question['type'], $allowed_question_types)) {
				echo '<option value="'.$question['question_id'].'"';
				if ($_GET['yaxis'] == $question['question_id']) {
					echo ' selected="selected"';
				}
				echo '">'.api_substr(strip_tags($question['question']), 0, 50).'</option>';
			}
		}
		echo '</select><br /><br />';
		echo '<button class="save" type="submit" name="Submit" value="Submit">'.get_lang('CompareQuestions').'</button>';
		echo '</form>';

		// Getting all the information of the x axis
		if (isset($_GET['xaxis']) && is_numeric($_GET['xaxis'])) {
			$question_x = survey_manager::get_question($_GET['xaxis']);
		}

		// Getting all the information of the y axis
		if (isset($_GET['yaxis']) && is_numeric($_GET['yaxis'])) {
			$question_y = survey_manager::get_question($_GET['yaxis']);
		}

		if (isset($_GET['xaxis']) && is_numeric($_GET['xaxis']) && isset($_GET['yaxis']) && is_numeric($_GET['yaxis'])) {
			// Getting the answers of the two questions
			$answers_x = SurveyUtil::get_answers_of_question_by_user($_GET['survey_id'], $_GET['xaxis']);
			$answers_y = SurveyUtil::get_answers_of_question_by_user($_GET['survey_id'], $_GET['yaxis']);

			// Displaying the table
			echo '<table border="1" class="data_table">';

			// The header
			echo '	<tr>';
			for ($ii = 0; $ii <= count($question_x['answers']); $ii++) {
				if ($ii == 0) {
					echo '		<th>&nbsp;</th>';
				} else {
					if ($question_x['type'] == 'score') {
						for ($x = 1; $x <= $question_x['maximum_score']; $x++) {
							echo '		<th>'.$question_x['answers'][($ii-1)].'<br />'.$x.'</th>';
						}
						$x = '';
					} else {
						echo '		<th>'.$question_x['answers'][($ii-1)].'</th>';
					}
				}
			}
			echo '	</tr>';

			// The main part
			for ($ij = 0; $ij < count($question_y['answers']); $ij++) {
				// The Y axis is a scoring question type so we have more rows than the options (actually options * maximum score)
				if ($question_y['type'] == 'score') {
					for ($y = 1; $y <= $question_y['maximum_score']; $y++) {
						echo '	<tr>';
						for ($ii = 0; $ii <= count($question_x['answers']); $ii++) {
							if ($question_x['type'] == 'score') {
								for ($x = 1; $x <= $question_x['maximum_score']; $x++) {
									if ($ii == 0) {
										echo '		<th>'.$question_y['answers'][($ij)].' '.$y.'</th>';
										break;
									} else {
										echo '		<td align="center">';
										echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)], $x, $y);
										echo '</td>';
									}
								}
							} else {
								if ($ii == 0) {
									echo '		<th>'.$question_y['answers'][($ij)].' '.$y.'</th>';
								} else {
									echo '		<td align="center">';
									echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)], 0, $y);
									echo '</td>';
								}
							}
						}
						echo '	</tr>';
					}
				}
				// The Y axis is NOT a score question type so the number of rows = the number of options
				else {
					echo '	<tr>';
					for ($ii = 0; $ii <= count($question_x['answers']); $ii++) {
							if ($question_x['type'] == 'score') {
								for ($x = 1; $x <= $question_x['maximum_score']; $x++) {
									if ($ii == 0) {
										echo '		<th>'.$question_y['answers'][($ij)].'</th>';
										break;
									} else {
										echo '		<td align="center">';
										echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)], $x, 0);
										echo '</td>';
									}
								}
							} else {
								if ($ii == 0) {
									echo '		<th>'.$question_y['answers'][($ij)].'</th>';
								} else {
									echo '		<td align="center">';
									echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)]);
									echo '</td>';
								}
							}
					}
					echo '	</tr>';
				}
			}
			echo '</table>';
		}
	}

	/**
	 * Get all the answers of a question grouped by user
	 *
	 * @param	integer	Survey ID
	 * @param	integer	Question ID
	 * @return 	Array	Array containing all answers of all users, grouped by user
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007 - Updated March 2008
	 */
	static function get_answers_of_question_by_user($survey_id, $question_id) {
	    $course_id = api_get_course_int_id();
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);

		$sql = "SELECT * FROM $table_survey_answer
					WHERE c_id = $course_id AND survey_id='".Database::escape_string($survey_id)."'
					AND question_id='".Database::escape_string($question_id)."'
					ORDER BY USER ASC";
		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			if ($row['value'] == 0) {
				$return[$row['user']][] = $row['option_id'];
			} else {
				$return[$row['user']][] = $row['option_id'].'*'.$row['value'];
			}
		}
		return $return;
	}

	/**
	 * Count the number of users who answer positively on both options
	 *
	 * @param	array	All answers of the x axis
	 * @param	array	All answers of the y axis
	 * @param	integer x axis value (= the option_id of the first question)
	 * @param	integer y axis value (= the option_id of the second question)
	 * @return	integer Number of users who have answered positively to both options
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version February 2007
	 */
	static function comparative_check($answers_x, $answers_y, $option_x, $option_y, $value_x = 0, $value_y = 0) {
		if ($value_x == 0) {
			$check_x = $option_x;
		} else {
			$check_x = $option_x.'*'.$value_x;
		}
		if ($value_y == 0) {
			$check_y = $option_y;
		} else {
			$check_y = $option_y.'*'.$value_y;
		}

		$counter = 0;
		if (is_array($answers_x)) {
			foreach ($answers_x as $user => & $answers) {
				// Check if the user has given $option_x as answer
				if (in_array($check_x, $answers)) {
					// Check if the user has given $option_y as an answer
					if (in_array($check_y, $answers_y[$user])) {
						$counter++;
					}
				}
			}
		}
		return $counter;
	}

	/**
	 * Get all the information about the invitations of a certain survey
	 *
	 * @return	array	Lines of invitation [user, code, date, empty element]
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @todo use survey_id parameter instead of $_GET
	 */
	static function get_survey_invitations_data() {
	    $course_id = api_get_course_int_id();
		// Database table definition
		$table_survey_invitation 		= Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_user 					= Database :: get_main_table(TABLE_MAIN_USER);

		$sql = "SELECT
					survey_invitation.user as col1,
					survey_invitation.invitation_code as col2,
					survey_invitation.invitation_date as col3,
					'' as col4
					FROM $table_survey_invitation survey_invitation
                LEFT JOIN $table_user user
                ON survey_invitation.user = user.user_id
                WHERE
                    survey_invitation.c_id = $course_id AND
                    survey_invitation.survey_id = '".Database::escape_string($_GET['survey_id'])."' AND
                    session_id='".api_get_session_id()."'  ";
		$res = Database::query($sql);
		while ($row = Database::fetch_array($res)) {
			$survey_invitation_data[] = $row;
		}
		return $survey_invitation_data;
	}

	/**
	 * Get the total number of survey invitations for a given survey (through $_GET['survey_id'])
	 *
	 * @return	integer	Total number of survey invitations
	 *
	 * @todo use survey_id parameter instead of $_GET
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function get_number_of_survey_invitations()
    {
	    $course_id = api_get_course_int_id();

		// Database table definition
		$table_survey_invitation 		= Database :: get_course_table(TABLE_SURVEY_INVITATION);

		$sql = "SELECT count(user) AS total
		        FROM $table_survey_invitation
		        WHERE
                    c_id = $course_id AND
                    survey_id='".Database::escape_string($_GET['survey_id'])."' AND
                    session_id='".api_get_session_id()."' ";
		$res = Database::query($sql);
		$row = Database::fetch_array($res,'ASSOC');
		return $row['total'];
	}

	/**
	 * Save the invitation mail
	 *
	 * @param string 	Text of the e-mail
	 * @param integer	Whether the mail contents are for invite mail (0, default) or reminder mail (1)
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function save_invite_mail($mailtext, $mail_subject, $reminder = 0) {
	    $course_id = api_get_course_int_id();
		// Database table definition
		$table_survey = Database :: get_course_table(TABLE_SURVEY);

		// Reminder or not
		if ($reminder == 0) {
			$mail_field = 'invite_mail';
		} else {
			$mail_field = 'reminder_mail';
		}

		$sql = "UPDATE $table_survey
		        SET
		        mail_subject='".Database::escape_string($mail_subject)."',
		        $mail_field = '".Database::escape_string($mailtext)."'
		        WHERE c_id = $course_id AND survey_id = '".Database::escape_string($_GET['survey_id'])."'";
		Database::query($sql);
	}

	/**
	 * This function saves all the invitations of course users and additional users in the database
	 * and sends the invitations by email
	 *
	 * @param	array	Users array can be both a list of course uids AND a list of additional emailaddresses
	 * @param 	string	Title of the invitation, used as the title of the mail
	 * @param 	string	Text of the invitation, used as the text of the mail.
	 * 				 The text has to contain a **link** string or this will automatically be added to the end
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
     * @author Julio Montoya - Adding auto-generated link support
	 * @version January 2007
	 *
	 */
	static function save_invitations($users_array, $invitation_title, $invitation_text, $reminder = 0, $sendmail = 0, $remindUnAnswered = 0)
    {
		if (!is_array($users_array)) return 0; // Should not happen

		// Getting the survey information
		$survey_data = survey_manager::get_survey($_GET['survey_id']);
		$survey_invitations = SurveyUtil::get_invitations($survey_data['survey_code']);
		$already_invited = SurveyUtil::get_invited_users($survey_data['code']);

		// Remind unanswered is a special version of remind all reminder
		$exclude_users = array();
		if ($remindUnAnswered == 1) { // Remind only unanswered users
			$reminder = 1;
			$exclude_users = survey_manager::get_people_who_filled_survey($_GET['survey_id']);
		}

		$counter = 0;  // Nr of invitations "sent" (if sendmail option)
		$course_id = api_get_course_int_id();

        $session_id = api_get_session_id();

		foreach ($users_array as $key=>$value) {
			if (!isset($value) || $value == '') continue;
			// Skip user if reminding only unanswered people
			if (in_array($value, $exclude_users)) continue;
			// Get the unique invitation code if we already have it
			if ($reminder == 1 && array_key_exists($value, $survey_invitations)) {
				$invitation_code = $survey_invitations[$value]['invitation_code'];
			} else {
				$invitation_code = md5($value.microtime());
			}
			$new_user = false; // User not already invited
			// Store the invitation if user_id not in $already_invited['course_users'] OR email is not in $already_invited['additional_users']
			$addit_users_array = isset($already_invited['additional_users']) && !empty($already_invited['additional_users']) ? explode(';', $already_invited['additional_users']) : array();

			$my_alredy_invited = ($already_invited['course_users'] == null) ? array() : $already_invited['course_users'];
			if ((is_numeric($value) && !in_array($value, $my_alredy_invited)) || (!is_numeric($value) && !in_array($value, $addit_users_array))) {
				$new_user = true;
				if (!array_key_exists($value, $survey_invitations)) {
                    $params = array(
                        'c_id' => $course_id,
                        'session_id' => $session_id,
                        'user' => $value,
                        'survey_code' => $survey_data['code'],
                        'invitation_code' => $invitation_code,
                        'invitation_date' => api_get_utc_datetime()
                    );
					self::save_invitation($params);
				}
			}
			// Send the email if checkboxed
			if (($new_user || $reminder == 1) && $sendmail != 0) {
				// Make a change for absolute url
				if (isset($invitation_text)) {
                    $invitation_text = api_html_entity_decode($invitation_text, ENT_QUOTES);
					$invitation_text = str_replace('src="../../', 'src="'.api_get_path(WEB_PATH), $invitation_text);
					$invitation_text = trim(stripslashes($invitation_text));
				}
				SurveyUtil::send_invitation_mail($value, $invitation_code, $invitation_title, $invitation_text);
				$counter++;
			}
		}
		return $counter; // Number of invitations sent
	}

    static function save_invitation($params)
    {
        // Database table to store the invitations data
        $table_survey_invitation = Database::get_course_table(TABLE_SURVEY_INVITATION);
        if (!empty($params['c_id']) && !empty($params['user']) && !empty($params['survey_code'])) {
            return Database::insert($table_survey_invitation, $params);
        }
        return false;
    }

	/**
	 * Send the invitation by mail.
	 *
	 * @param int invitedUser - the userId (course user) or emailaddress of additional user
	 * $param string $invitation_code - the unique invitation code for the URL
	 * @return	void
	 */
	static function send_invitation_mail($invitedUser, $invitation_code, $invitation_title, $invitation_text)
    {
        $_user = api_get_user_info();
        $_course = api_get_course_info();

		// Replacing the **link** part with a valid link for the user
		$survey_link = api_get_path(WEB_CODE_PATH).'survey/fillsurvey.php?course='.$_course['code'].'&invitationcode='.$invitation_code;
		$text_link = '<a href="'.$survey_link.'">'.get_lang('ClickHereToAnswerTheSurvey')."</a><br />\r\n<br />\r\n".get_lang('OrCopyPasteTheFollowingUrl')." <br />\r\n ".$survey_link;

		$replace_count = 0;
		$full_invitation_text = api_str_ireplace('**link**', $text_link ,$invitation_text, $replace_count);
		if ($replace_count < 1) {
			$full_invitation_text = $full_invitation_text."<br />\r\n<br />\r\n".$text_link;
		}

        // Sending the mail
		$sender_name  = api_get_person_name($_user['firstName'], $_user['lastName'], null, PERSON_NAME_EMAIL_ADDRESS);
		$sender_email = $_user['mail'];
        $sender_user_id = api_get_user_id();

		$replyto = array();
		if (api_get_setting('survey_email_sender_noreply') == 'noreply') {
			$noreply = api_get_setting('noreply_email_address');
			if (!empty($noreply)) {
				$replyto['Reply-to'] = $noreply;
				$sender_name = $noreply;
				$sender_email = $noreply;
                $sender_user_id = null;
			}
		}

		// Optionally: finding the e-mail of the course user
		if (is_numeric($invitedUser)) {
			$table_user = Database :: get_main_table(TABLE_MAIN_USER);
			$sql = "SELECT firstname, lastname, email FROM $table_user WHERE user_id='".Database::escape_string($invitedUser)."'";
			$result = Database::query($sql);
			$row = Database::fetch_array($result);
			$recipient_email = $row['email'];
			$recipient_name = api_get_person_name($row['firstname'], $row['lastname'], null, PERSON_NAME_EMAIL_ADDRESS);

            MessageManager::send_message($invitedUser, $invitation_title, $full_invitation_text, null, null, null, null, null, null, $sender_user_id);

		} else {
			/** @todo check if the address is a valid email	 */
			$recipient_email = $invitedUser;
            @api_mail_html($recipient_name, $recipient_email, $invitation_title, $full_invitation_text, $sender_name, $sender_email, $replyto);
		}
	}

	/**
	 * This function recalculates the number of users who have been invited and updates the survey table with this value.
	 *
	 * @param	string	Survey code
	 * @return	void
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function update_count_invited($survey_code)
    {
	    $course_id = api_get_course_int_id();

		// Database table definition
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_survey 				= Database :: get_course_table(TABLE_SURVEY);

		// Counting the number of people that are invited
		$sql = "SELECT count(user) as total FROM $table_survey_invitation
		        WHERE c_id = $course_id AND survey_code = '".Database::escape_string($survey_code)."'";
		$result = Database::query($sql);
		$row = Database::fetch_array($result);
		$total_invited = $row['total'];

		// Updating the field in the survey table
		$sql = "UPDATE $table_survey
		        SET invited = '".Database::escape_string($total_invited)."'
		        WHERE c_id = $course_id AND code = '".Database::escape_string($survey_code)."'";
		Database::query($sql);
	}

	/**
	 * This function gets all the invited users for a given survey code.
	 *
	 * @param	string	Survey code
	 * @param	string	optional - course database
	 * @return 	array	Array containing the course users and additional users (non course users)
	 *
	 * @todo consider making $defaults['additional_users'] also an array
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
     * @author Julio Montoya, adding c_id fixes - Dec 2012
	 * @version January 2007
	 */
	static function get_invited_users($survey_code, $course_code = '', $session_id = 0)
    {
	    if (!empty($course_code)) {
            $course_info = api_get_course_info($course_code);
            $course_id = $course_info['real_id'];
        } else {
            $course_id = api_get_course_int_id();
        }

        if (empty($session_id)) {
            $session_id = api_get_session_id();
        }

	    $table_survey_invitation = Database :: get_course_table(TABLE_SURVEY_INVITATION);
        $table_user = Database :: get_main_table(TABLE_MAIN_USER);

		// Selecting all the invitations of this survey AND the additional emailaddresses (the left join)
		$order_clause = api_sort_by_first_name() ? ' ORDER BY firstname, lastname' : ' ORDER BY lastname, firstname';
		$sql = "SELECT user
				FROM $table_survey_invitation as table_invitation
				WHERE
				    table_invitation.c_id = $course_id AND
                    survey_code='".Database::escape_string($survey_code)."' AND
                    session_id = $session_id
                ";

		$defaults = array();
		$defaults['course_users'] = array();
		$defaults['additional_users'] = array();

		$result = Database::query($sql);
		while ($row = Database::fetch_array($result)) {
			if (is_numeric($row['user'])) {
				$defaults['course_users'][] = $row['user'];
			} else {
                if (!empty($row['user'])) {
                    $defaults['additional_users'][] = $row['user'];
                }
			}
		}

        if (!empty($defaults['course_users'])) {
            $user_ids = implode("','", $defaults['course_users']);
            $sql = "SELECT user_id FROM $table_user WHERE user_id IN ('$user_ids') $order_clause";
            $result = Database::query($sql);
            $fixed_users = array();
            while ($row = Database::fetch_array($result)) {
                $fixed_users[] = $row['user_id'];
            }
            $defaults['course_users'] = $fixed_users;
        }

        if (!empty($defaults['additional_users'])) {
            $defaults['additional_users'] = implode(';', $defaults['additional_users']);
        }
        //error_log(print_r($defaults, 1));
		return $defaults;
	}

	/**
	 * Get all the invitations
	 *
	 * @param	string	Survey code
	 * @return	array	Database rows matching the survey code
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version September 2007
	 */
	static function get_invitations($survey_code)
    {
	    $course_id = api_get_course_int_id();
		// Database table definition
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);

		$sql = "SELECT * FROM $table_survey_invitation
		        WHERE
		            c_id = $course_id AND
		            survey_code = '".Database::escape_string($survey_code)."'";
		$result = Database::query($sql);
		$return = array();
		while ($row = Database::fetch_array($result)) {
			$return[$row['user']] = $row;
		}
		return $return;
	}

	/**
	 * This function displays the form for searching a survey
	 *
	 * @return	void	(direct output)
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 *
	 * @todo use quickforms
	 * @todo consider moving this to surveymanager.inc.lib.php
	 */
	static function display_survey_search_form()
    {
		echo '<form class="form-horizontal" method="get" action="'.api_get_path(WEB_CODE_PATH).'survey/survey_list.php?search=advanced">';
		echo '<legend>'.get_lang('SearchASurvey').'</legend>';
		echo '	<div class="control-group">
					<label class="control-label">
						'.get_lang('Title').'
					</label>
					<div class="controls">
						<input type="text" id="search_title" name="keyword_title"/>
					</div>
				</div>';
		echo '	<div class="control-group">
					<label class="control-label">
						'.get_lang('Code').'
					</label>
					<div class="controls">
						<input type="text" name="keyword_code"/>
					</div>
				</div>';
		echo '	<div class="control-group">
					<label class="control-label">
						'.get_lang('Language').'
					</label>
					<div class="controls">';
		echo '			<select name="keyword_language"><option value="%">'.get_lang('All').'</option>';
		$languages = api_get_languages();
		foreach ($languages['name'] as $index => & $name) {
			echo '<option value="'.$languages['folder'][$index].'">'.$name.'</option>';
		}
		echo '			</select>';
		echo '		</div>
				</div>';
		echo '<input type="hidden" name="cidReq" value="'.api_get_course_id().'"/>';
		echo '	<div class="control-group">
					<div class="controls">
						<button class="search" type="submit" name="do_search">'.get_lang('Search').'</button>
					</div>
				</div>';
		echo '</form>';
		echo '<div style="clear: both;margin-bottom: 10px;"></div>';
	}

	/**
	 * This function displays the sortable table with all the surveys
	 *
	 * @return	void	(direct output)
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function display_survey_list()
    {
		$parameters = array();
		$parameters['cidReq'] = api_get_course_id();
		if (isset($_GET['do_search']) && $_GET['do_search']) {
			$message = get_lang('DisplaySearchResults').'<br />';
			$message .= '<a href="'.api_get_self().'?'.api_get_cidreq().'">'.get_lang('DisplayAll').'</a>';
			Display::display_normal_message($message, false);
		}

		// Create a sortable table with survey-data
		$table = new SortableTable('surveys', 'get_number_of_surveys', 'get_survey_data', 2);
		$table->set_additional_parameters($parameters);
		$table->set_header(0, '', false);
		$table->set_header(1, get_lang('SurveyName'));
		$table->set_header(2, get_lang('SurveyCode'));
		$table->set_header(3, get_lang('NumberOfQuestions'));
		$table->set_header(4, get_lang('Author'));
		//$table->set_header(5, get_lang('Language'));
		//$table->set_header(6, get_lang('Shared'));
		$table->set_header(5, get_lang('AvailableFrom'));
		$table->set_header(6, get_lang('AvailableUntil'));
		$table->set_header(7, get_lang('Invite'));
		$table->set_header(8, get_lang('Anonymous'));
		$table->set_header(9, get_lang('Modify'), false, 'width="150"');
		$table->set_column_filter(8, 'anonymous_filter');
		$table->set_column_filter(9, 'modify_filter');
		$table->set_form_actions(array('delete' => get_lang('DeleteSurvey')));
		$table->display();
	}

	function display_survey_list_for_coach()
    {
		$parameters = array();
		$parameters['cidReq']=api_get_course_id();
		if (isset($_GET['do_search'])) {
			$message = get_lang('DisplaySearchResults').'<br />';
			$message .= '<a href="'.api_get_self().'?'.api_get_cidreq().'">'.get_lang('DisplayAll').'</a>';
			Display::display_normal_message($message, false);
		}

		// Create a sortable table with survey-data
		$table = new SortableTable('surveys_coach', 'get_number_of_surveys_for_coach', 'get_survey_data_for_coach', 2);
		$table->set_additional_parameters($parameters);
		$table->set_header(0, '', false);
		$table->set_header(1, get_lang('SurveyName'));
		$table->set_header(2, get_lang('SurveyCode'));
		$table->set_header(3, get_lang('NumberOfQuestions'));
		$table->set_header(4, get_lang('Author'));
		//$table->set_header(5, get_lang('Language'));
		//$table->set_header(6, get_lang('Shared'));
		$table->set_header(5, get_lang('AvailableFrom'));
		$table->set_header(6, get_lang('AvailableUntil'));
		$table->set_header(7, get_lang('Invite'));
		$table->set_header(8, get_lang('Anonymous'));
		$table->set_header(9, get_lang('Modify'), false, 'width="130"');
		$table->set_column_filter(8, 'anonymous_filter');
		$table->set_column_filter(9, 'modify_filter_for_coach');
		$table->display();
	}

	/**
	 * This function changes the modify column of the sortable table
	 *
	 * @param integer $survey_id the id of the survey
	 * @return html code that are the actions that can be performed on any survey
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function modify_filter($survey_id)
    {
		$survey_id = Security::remove_XSS($survey_id);
		$return = '';

		// Coach can see that only if the survey is in his session
		if (api_is_allowed_to_edit() || api_is_element_in_the_session(TOOL_SURVEY, $survey_id)) {
			$return .= '<a href="'.api_get_path(WEB_CODE_PATH).'survey/create_new_survey.php?'.api_get_cidreq().'&amp;action=edit&amp;survey_id='.$survey_id.'">'.Display::return_icon('edit.png', get_lang('Edit'),'',ICON_SIZE_SMALL).'</a>';
            if (survey_manager::survey_generation_hash_available()) {
                $return .=  Display::url(
                    Display::return_icon('new_link.png', get_lang('GenerateSurveyAccessLink'),'',ICON_SIZE_SMALL),
                    api_get_path(WEB_CODE_PATH).'survey/generate_link.php?survey_id='.$survey_id.'&'.api_get_cidreq()
                );
            }
			$return .= ' <a href="'.api_get_path(WEB_CODE_PATH).'survey/survey_list.php?'.api_get_cidreq().'&amp;action=empty&amp;survey_id='.$survey_id.'" onclick="javascript: if(!confirm(\''.addslashes(api_htmlentities(get_lang("EmptySurvey").'?')).'\')) return false;">'.Display::return_icon('clean.png', get_lang('EmptySurvey'),'',ICON_SIZE_SMALL).'</a>&nbsp;';
		}
		$return .= '<a href="'.api_get_path(WEB_CODE_PATH).'survey/preview.php?'.api_get_cidreq().'&amp;survey_id='.$survey_id.'">'.Display::return_icon('preview_view.png', get_lang('Preview'),'',ICON_SIZE_SMALL).'</a>&nbsp;';
		$return .= '<a href="'.api_get_path(WEB_CODE_PATH).'survey/survey_invite.php?'.api_get_cidreq().'&amp;survey_id='.$survey_id.'">'.Display::return_icon('mail_send.png', get_lang('Publish'),'',ICON_SIZE_SMALL).'</a>&nbsp;';
		$return .= '<a href="'.api_get_path(WEB_CODE_PATH).'survey/reporting.php?'.api_get_cidreq().'&amp;survey_id='.$survey_id.'">'.Display::return_icon('stats.png', get_lang('Reporting'),'',ICON_SIZE_SMALL).'</a>';
		if (api_is_allowed_to_edit() || api_is_element_in_the_session(TOOL_SURVEY, $survey_id)) {
            $return .= '<a href="'.api_get_path(WEB_CODE_PATH).'survey/survey_list.php?'.api_get_cidreq().'&amp;action=delete&amp;survey_id='.$survey_id.'" onclick="javascript: if(!confirm(\''.addslashes(api_htmlentities(get_lang("DeleteSurvey").'?', ENT_QUOTES)).'\')) return false;">'.Display::return_icon('delete.png', get_lang('Delete'),'',ICON_SIZE_SMALL).'</a>&nbsp;';
		}
		return $return;
	}

	static function modify_filter_for_coach($survey_id)
    {

		$survey_id = Security::remove_XSS($survey_id);
		//$return = '<a href="create_new_survey.php?'.api_get_cidreq().'&amp;action=edit&amp;survey_id='.$survey_id.'">'.Display::return_icon('edit.gif', get_lang('Edit')).'</a>';
		//$return .= '<a href="survey_list.php?'.api_get_cidreq().'&amp;action=delete&amp;survey_id='.$survey_id.'" onclick="javascript:if(!confirm(\''.addslashes(api_htmlentities(get_lang("DeleteSurvey").'?', ENT_QUOTES)).'\')) return false;">'.Display::return_icon('delete.gif', get_lang('Delete')).'</a>';
		//$return .= '<a href="create_survey_in_another_language.php?id_survey='.$survey_id.'">'.Display::return_icon('copy.gif', get_lang('Copy')).'</a>';
		//$return .= '<a href="survey.php?survey_id='.$survey_id.'">'.Display::return_icon('add.gif', get_lang('Add')).'</a>';
		$return = '<a href="'.api_get_path(WEB_CODE_PATH).'survey/preview.php?'.api_get_cidreq().'&amp;survey_id='.$survey_id.'">'.Display::return_icon('preview_view.png', get_lang('Preview'),'',ICON_SIZE_SMALL).'</a>&nbsp;';
		$return .= '<a href="'.api_get_path(WEB_CODE_PATH).'survey/survey_invite.php?'.api_get_cidreq().'&amp;survey_id='.$survey_id.'">'.Display::return_icon('mail_send.png', get_lang('Publish'),'',ICON_SIZE_SMALL).'</a>&nbsp;';
		$return .= '<a href="'.api_get_path(WEB_CODE_PATH).'survey/survey_list.php?'.api_get_cidreq().'&amp;action=empty&amp;survey_id='.$survey_id.'" onclick="javascript: if(!confirm(\''.addslashes(api_htmlentities(get_lang("EmptySurvey").'?', ENT_QUOTES)).'\')) return false;">'.Display::return_icon('clean.png', get_lang('EmptySurvey'),'',ICON_SIZE_SMALL).'</a>&nbsp;';
		//$return .= '<a href="reporting.php?'.api_get_cidreq().'&amp;survey_id='.$survey_id.'">'.Display::return_icon('statistics.gif', get_lang('Reporting')).'</a>';
		return $return;
	}

	/**
	 * Returns "yes" when given parameter is one, "no" for any other value
	 * @param	integer	Whether anonymous or not
	 * @return	string	"Yes" or "No" in the current language
	 */
	static function anonymous_filter($anonymous) {
		if ($anonymous == 1) {
			return get_lang('Yes');
		} else {
			return get_lang('No');
		}
	}


	/**
	 * This function handles the search restriction for the SQL statements
	 *
	 * @return	string	Part of a SQL statement or false on error
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function survey_search_restriction() {
		if (isset($_GET['do_search'])) {
			if ($_GET['keyword_title'] != '') {
				$search_term[] = 'title like "%" \''.Database::escape_string($_GET['keyword_title']).'\' "%"';
			}
			if ($_GET['keyword_code'] != '') {
				$search_term[] = 'code =\''.Database::escape_string($_GET['keyword_code']).'\'';
			}
			if ($_GET['keyword_language'] != '%') {
				$search_term[] = 'lang =\''.Database::escape_string($_GET['keyword_language']).'\'';
			}
			$my_search_term = ($search_term == null) ? array() : $search_term;
			$search_restriction = implode(' AND ', $my_search_term);
			return $search_restriction;
		} else {
			return false;
		}
	}

	/**
	 * This function calculates the total number of surveys
	 *
	 * @return	integer	Total number of surveys
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version January 2007
	 */
	static function get_number_of_surveys()
    {
        $table_survey = Database :: get_course_table(TABLE_SURVEY);
        $course_id = api_get_course_int_id();

		$search_restriction = SurveyUtil::survey_search_restriction();
		if ($search_restriction) {
			$search_restriction = 'WHERE c_id = '.$course_id.' AND '.$search_restriction;
		} else {
		    $search_restriction = "WHERE c_id = $course_id";
		}
		$sql = "SELECT count(survey_id) AS total_number_of_items
		        FROM ".$table_survey.' '.$search_restriction;
		$res = Database::query($sql);
		$obj = Database::fetch_object($res);
		return $obj->total_number_of_items;
	}

	static function get_number_of_surveys_for_coach()
    {
		// Ugly fix
		require_once api_get_path(LIBRARY_PATH).'surveymanager.lib.php';
		$survey_tree = new SurveyTree();
		return count($survey_tree->get_last_children_from_branch($survey_tree->surveylist));
	}

	/**
	 * This function gets all the survey data that is to be displayed in the sortable table
	 *
	 * @param int $from
	 * @param int $number_of_items
	 * @param int $column
	 * @param string $direction
	 * @return unknown
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @author Julio Montoya <gugli100@gmail.com>, Beeznest - Adding intvals
	 * @version January 2007
	 */
	static function get_survey_data($from, $number_of_items, $column, $direction)
    {
        $table_survey = Database :: get_course_table(TABLE_SURVEY);
        $table_user = Database :: get_main_table(TABLE_MAIN_USER);
        $table_survey_question = Database :: get_course_table(TABLE_SURVEY_QUESTION);
        $_user = api_get_user_info();

		// Searching
		$search_restriction = SurveyUtil::survey_search_restriction();
		if ($search_restriction) {
			$search_restriction = ' AND '.$search_restriction;
		}
		$from = intval($from);
		$number_of_items = intval($number_of_items);
		$column = intval($column);
		if (!in_array(strtolower($direction), array('asc', 'desc'))) {
		    $direction = 'asc';
		}

		// Condition for the session
		$session_id = api_get_session_id();
		$condition_session = api_get_session_condition($session_id);
		$course_id = api_get_course_int_id();

		$sql = "SELECT
					survey.survey_id AS col0,
					survey.title AS col1,
					survey.code AS col2,
					count(survey_question.question_id) AS col3,
					".(api_is_western_name_order() ? "CONCAT(user.firstname, ' ', user.lastname)" : "CONCAT(user.lastname, ' ', user.firstname)")."	AS col4,
					survey.avail_from AS col5,
					survey.avail_till AS col6,
					survey.invited AS col7,
					survey.anonymous AS col8,
					survey.survey_id AS col9,
					survey.session_id AS session_id,
					survey.answered,
					survey.invited
				 FROM $table_survey survey
                    LEFT JOIN $table_survey_question survey_question
                    ON (survey.survey_id = survey_question.survey_id AND survey_question.c_id = $course_id)
                    LEFT JOIN $table_user user
                    ON (survey.author = user.user_id)
				 WHERE survey.c_id = $course_id
				 $search_restriction
				 $condition_session ";
		$sql .= " GROUP BY survey.survey_id";
		$sql .= " ORDER BY col$column $direction ";
		$sql .= " LIMIT $from,$number_of_items";

		$res = Database::query($sql);
		$surveys = array();
		$array = array();
		while ($survey = Database::fetch_array($res)) {

			$array[0] = $survey[0];
			$array[1] = Display::url(
                $survey[1],
                api_get_path(WEB_CODE_PATH).'survey/survey.php?survey_id='.$survey[0].'&'.api_get_cidreq()
            );

			// Validation when belonging to a session
			$session_img = api_get_session_image($survey['session_id'], $_user['status']);
			$array[2] = $survey[2] . $session_img;
			$array[3] = $survey[3];
			$array[4] = $survey[4];
			$array[5] = $survey[5];
			$array[6] = $survey[6];
			$array[7] =
                Display::url(
                    $survey['answered'],
                    api_get_path(WEB_CODE_PATH).'survey/survey_invitation.php?view=answered&survey_id='.$survey[0].'&'.api_get_cidreq()
                ).' / '.
                Display::url(
                    $survey['invited'],
                    api_get_path(WEB_CODE_PATH).'survey/survey_invitation.php?view=invited&survey_id='.$survey[0].'&'.api_get_cidreq()
                );

			$array[8] = $survey[8];
			$array[9] = $survey[9];
			//$array[10] = $survey[10];
			$surveys[] = $array;
		}
		return $surveys;
	}

	static function get_survey_data_for_coach($from, $number_of_items, $column, $direction)
    {
		require_once api_get_path(LIBRARY_PATH).'surveymanager.lib.php';
		$survey_tree = new SurveyTree();
		$last_version_surveys = $survey_tree->get_last_children_from_branch($survey_tree->surveylist);
		$list = array();
		foreach ($last_version_surveys as & $survey) {
			$list[]=$survey['id'];
		}
		if (count($list) > 0) {
			$list_condition = " AND survey.survey_id IN (".implode(',',$list).") ";
		} else {
			$list_condition = '';
		}

	    $from = intval($from);
        $number_of_items = intval($number_of_items);
        $column = intval($column);
        if (!in_array(strtolower($direction), array('asc', 'desc'))) {
            $direction = 'asc';
        }

		$table_survey 			= Database :: get_course_table(TABLE_SURVEY);
		$table_survey_question 	= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_user 			= Database :: get_main_table(TABLE_MAIN_USER);

		$course_id = api_get_course_int_id();

		//IF(is_shared<>0,'V','-')	 					AS col6,
		$sql = "SELECT ".
                   "survey.survey_id							AS col0, ".
                   "survey.title	                            AS col1, ".
                   "survey.code									AS col2, ".
                   "count(survey_question.question_id)			AS col3, ".
                   (api_is_western_name_order() ? "CONCAT(user.firstname, ' ', user.lastname)" : "CONCAT(user.lastname, ' ', user.firstname)")."	AS col4, ".
                   "survey.avail_from							AS col5, ".
                   "survey.avail_till							AS col6, ".
                   "CONCAT('<a href=\"survey_invitation.php?view=answered&amp;survey_id=',survey.survey_id,'\">',survey.answered,'</a> / <a href=\"survey_invitation.php?view=invited&amp;survey_id=',survey.survey_id,'\">',survey.invited, '</a>')	AS col7, ".
                   "survey.anonymous							AS col8, ".
                   "survey.survey_id							AS col9  ".
                   "FROM $table_survey survey ".
                   "LEFT JOIN $table_survey_question survey_question ON (survey.survey_id = survey_question.survey_id AND survey.c_id = survey_question.c_id) ".
                   ", $table_user user
               WHERE survey.author = user.user_id AND survey.c_id = $course_id $list_condition ";
		$sql .= " GROUP BY survey.survey_id";
		$sql .= " ORDER BY col$column $direction ";
		$sql .= " LIMIT $from,$number_of_items";

		$res = Database::query($sql);
		$surveys = array();
		while ($survey = Database::fetch_array($res)) {
			$surveys[] = $survey;
		}
		return $surveys;
	}

	/**
	 * Display all the active surveys for the given course user
	 *
	 * @param int $user_id
	 *
	 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
	 * @version April 2007
	 */
	function survey_list_user($user_id)
    {
        $_course = api_get_course_info();
        $course_id = api_get_course_int_id();

		// Database table definitions
		$table_survey_question   = Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_invitation = Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_survey_answer     = Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$table_survey 			 = Database :: get_course_table(TABLE_SURVEY);
		$all_question_id = array();

		$sql = 'SELECT question_id FROM '.$table_survey_question." WHERE c_id = $course_id";
		$result = Database::query($sql);

		while($row = Database::fetch_array($result, 'ASSOC')) {
			$all_question_id[] = $row;
		}

		$count = 0;
		for ($i = 0; $i < count($all_question_id); $i++) {
			$sql = 'SELECT COUNT(*) as count
			        FROM '.$table_survey_answer.'
					WHERE
					    c_id = '.$course_id.' AND
					    question_id='.Database::escape_string($all_question_id[$i]['question_id']).' AND
					    user = '.api_get_user_id();
			$result = Database::query($sql);
			while ($row = Database::fetch_array($result, 'ASSOC')) {
				if ($row['count'] == 0) {
					$count++;
					break;
				}
			}
			if ($count > 0) {
				$link_add = true;
				break;
			}
		}
		echo '<table class="data_table">';
		echo '<tr>';
		echo '	<th>'.get_lang('SurveyName').'</th>';
		echo '	<th>'.get_lang('Anonymous').'</th>';
		echo '</tr>';
		$sql = "SELECT * FROM $table_survey survey, $table_survey_invitation survey_invitation
				WHERE
				survey_invitation.user 	= '".Database::escape_string($user_id)."' AND
				survey.code 			= survey_invitation.survey_code AND
				survey.avail_from 		<= '".date('Y-m-d H:i:s')."' AND
				survey.avail_till 		>= '".date('Y-m-d H:i:s')."' AND
				survey.c_id 			= $course_id AND
				survey_invitation.c_id = $course_id
				";
		$result = Database::query($sql);
		$counter = 0;
		while ($row = Database::fetch_array($result, 'ASSOC')) {
			// Get the user into survey answer table (user or anonymus)
			$sql = "SELECT user FROM $table_survey_answer
					WHERE c_id = $course_id AND survey_id = (SELECT survey_id from $table_survey WHERE code ='".Database::escape_string($row['code'])." AND c_id = $course_id')";
			$result_answer = Database::query($sql);
			$row_answer = Database::fetch_array($result_answer,'ASSOC');
			echo '<tr>';
			if ($row['answered'] == 0) {
				echo '<td><a href="'.api_get_path(WEB_CODE_PATH).'survey/fillsurvey.php?course='.$_course['sysCode'].'&amp;invitationcode='.$row['invitation_code'].'&amp;cidReq='.$_course['sysCode'].'">'.$row['title'].'</a></td>';
			} else {
				echo '<td>'.$row['title'].'</td>';
			}
			echo '<td>';
			echo ($row['anonymous'] == 1) ? get_lang('Yes') : get_lang('No');
			echo '</td>';
			echo '</tr>';
			if ($row['anonymous'] == 1) {
				$current_user_id = $_SESSION['surveyuser'];
			} else {
				$current_user_id = api_get_user_id();
			}
			$link_available = self::show_link_available(api_get_user_id(),$row['code'],$current_user_id);
			//todo check this link
			if ($link_add === true && $link_available === true) {
				//echo '<tr><td><a href="fillsurvey.php?user_id='.api_get_user_id().'&amp;course='.$_course['sysCode'].'&amp;invitationcode='.$row['invitation_code'].'&amp;cidReq='.$_course['sysCode'].'">'.get_lang('CompleteTheSurveysQuestions').'</a></td><td></td></tr>';
			}
		}
		echo '</table>';
	}

	/**
	 * Creates a multi array with the user fields that we can show. We look the visibility with the api_get_setting function
	 * The username is always NOT able to change it.
	 * @author Julio Montoya Armas <gugli100@gmail.com>, Chamilo: Personality Test modification
	 * @return array[value_name][name]
	 * 		   array[value_name][visibilty]
	 */
	static function make_field_list() {

		//	LAST NAME and FIRST NAME
		$field_list_array = array();
		$field_list_array['lastname']['name'] = get_lang('Lastname');
		$field_list_array['firstname']['name'] = get_lang('Firstname');

		if (api_get_setting('profile', 'name') != 'true') {
			$field_list_array['firstname']['visibility'] = 0;
			$field_list_array['lastname']['visibility'] = 0;
		} else {
			$field_list_array['firstname']['visibility'] = 1;
			$field_list_array['lastname']['visibility'] = 1;
		}

		$field_list_array['username']['name'] = get_lang('Username');
		$field_list_array['username']['visibility'] = 0;

		//	OFFICIAL CODE
		$field_list_array['official_code']['name'] = get_lang('OfficialCode');

		if (api_get_setting('profile', 'officialcode') != 'true') {
			$field_list_array['official_code']['visibility'] = 1;
		} else {
			$field_list_array['official_code']['visibility'] = 0;
		}

		// EMAIL
		$field_list_array['email']['name'] = get_lang('Email');
		if (api_get_setting('profile', 'email') != 'true') {
			$field_list_array['email']['visibility'] = 1;
		} else {
			$field_list_array['email']['visibility'] = 0;
		}

		// OPENID URL
		//$field_list_array[] = 'openid_authentication';
		/*
		if (is_profile_editable() && api_get_setting('openid_authentication') == 'true') {
			$form->addElement('text', 'openid', get_lang('OpenIDURL'), array('size' => 40));
			if (api_get_setting('profile', 'openid') != 'true') {
				$form->freeze('openid');
			}
			$form->applyFilter('openid', 'trim');
			//if (api_get_setting('registration', 'openid') == 'true')
			//	$form->addRule('openid', get_lang('ThisFieldIsRequired'), 'required');
		}*/

		// PHONE
		$field_list_array['phone']['name'] = get_lang('Phone');
		if (api_get_setting('profile', 'phone') != 'true') {
			$field_list_array['phone']['visibility'] = 0;
		} else {
			$field_list_array['phone']['visibility'] = 1;
		}
		//	LANGUAGE
		$field_list_array['language']['name'] = get_lang('Language');
		if (api_get_setting('profile', 'language') != 'true') {
			$field_list_array['language']['visibility'] = 0;
		} else {
			$field_list_array['language']['visibility'] = 1;
		}

		// EXTRA FIELDS
		$extra = UserManager::get_extra_fields(0, 50, 5, 'ASC');
		$extra_data = UserManager::get_extra_user_data(api_get_user_id(), true);
		foreach ($extra as $id => $field_details) {
			if ($field_details[6] == 0) {
				continue;
			}
			switch ($field_details[2]) {
				case UserManager::USER_FIELD_TYPE_TEXT:
					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 1;
					}
					break;
				case UserManager::USER_FIELD_TYPE_TEXTAREA:
					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 1;
					}
					break;
				case UserManager::USER_FIELD_TYPE_RADIO:

					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 1;
					}
					break;

				case UserManager::USER_FIELD_TYPE_SELECT:
					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 1;
					}
					break;

				case UserManager::USER_FIELD_TYPE_SELECT_MULTIPLE:
					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 1;
					}
					break;

				case UserManager::USER_FIELD_TYPE_DATE:
					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 1;
					}
					break;

				case UserManager::USER_FIELD_TYPE_DATETIME:
					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 1;
					}
					break;

				case UserManager::USER_FIELD_TYPE_DOUBLE_SELECT:
					$field_list_array['extra_'.$field_details[1]]['name'] = $field_details[3];
					if ($field_details[7] == 0) {
						$field_list_array['extra_'.$field_details[1]]['visibility'] = 0;
					} else {
						$field_list_array['extra_'.$field_details[1]]['visibility']=1;
					}
					/*
					foreach ($field_details[8] as $key => $element) {
						if ($element[2][0] == '*') {
							$values['*'][$element[0]] = str_replace('*','',$element[2]);
						} else {
							$values[0][$element[0]] = $element[2];
						}
					}

					$group = '';
					$group[] =& HTML_QuickForm::createElement('select', 'extra_'.$field_details[1], '', $values[0], '');
					$group[] =& HTML_QuickForm::createElement('select', 'extra_'.$field_details[1].'*', '', $values['*'], '');
					$form->addGroup($group, 'extra_'.$field_details[1], $field_details[3], '&nbsp;');
					if ($field_details[7] == 0)	$form->freeze('extra_'.$field_details[1]);

					// Recoding the selected values for double : if the user has selected certain values, we have to assign them to the correct select form
					if (key_exists('extra_'.$field_details[1], $extra_data)) {
						// Exploding all the selected values (of both select forms)
						$selected_values = explode(';',$extra_data['extra_'.$field_details[1]]);
						$extra_data['extra_'.$field_details[1]] = array();

						// Looping through the selected values and assigning the selected values to either the first or second select form
						foreach ($selected_values as $key => $selected_value) {
							if (key_exists($selected_value, $values[0])) {
								$extra_data['extra_'.$field_details[1]]['extra_'.$field_details[1]] = $selected_value;
							} else {
								$extra_data['extra_'.$field_details[1]]['extra_'.$field_details[1].'*'] = $selected_value;
							}
						}
					}*/
					break;
				case UserManager::USER_FIELD_TYPE_DIVIDER:
					//$form->addElement('static',$field_details[1], '<br /><strong>'.$field_details[3].'</strong>');
					break;
			}
		}
		return $field_list_array;
	}

	/**
	 * @author Isaac Flores Paz <florespaz@bidsoftperu.com>
	 * @param int $user_id - User ID
	 * @param int $user_id_answer - User in survey answer table (user id or anonymus)
	 * @return boolean
	 */
	static function show_link_available($user_id, $survey_code, $user_answer)
    {
		$table_survey             = Database :: get_course_table(TABLE_SURVEY);
		$table_survey_invitation  = Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_survey_answer      = Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$table_survey_question    = Database :: get_course_table(TABLE_SURVEY_QUESTION);

		$survey_code = Database::escape_string($survey_code);
		$user_id = Database::escape_string($user_id);
		$user_answer = Database::escape_string($user_answer);

		$course_id = api_get_course_int_id();


		$sql  = 'SELECT COUNT(*) as count FROM '.$table_survey_invitation.'
		          WHERE user='.$user_id.' AND survey_code="'.$survey_code.'" AND answered="1" AND c_id = '.$course_id.' ';

		$sql2 = 'SELECT COUNT(*) as count FROM '.$table_survey.' s INNER JOIN '.$table_survey_question.' q ON s.survey_id=q.survey_id
				 WHERE s.code="'.$survey_code.'" AND q.type NOT IN("pagebreak","comment") AND s.c_id = '.$course_id.' AND q.c_id = '.$course_id.' ';

		$sql3 = 'SELECT COUNT(DISTINCT question_id) as count FROM '.$table_survey_answer.'
				 WHERE survey_id=(SELECT survey_id FROM '.$table_survey.'
				 WHERE code="'.$survey_code.'" AND c_id = '.$course_id.' ) AND user="'.$user_answer.'" AND c_id = '.$course_id.' ';

		$result  = Database::query($sql);
		$result2 = Database::query($sql2);
		$result3 = Database::query($sql3);

		$row  = Database::fetch_array($result, 'ASSOC');
		$row2 = Database::fetch_array($result2, 'ASSOC');
		$row3 = Database::fetch_array($result3, 'ASSOC');

		if ($row['count'] == 1 && $row3['count'] != $row2['count']) {
			return true;
		} else {
			return false;
		}
	}
}