chamilo-lms2/main/exercice/testcategory.class.php

<?php
/* For licensing terms, see /license.txt */

/**
 * Class Testcategory
 * @author hubert.borderiou
 * @author Julio Montoya - several fixes
 * @todo rename to ExerciseCategory
 */
class Testcategory
{
	public $id;
	public $name;
	public $description;

	/**
	 * Constructor of the class Category
	 * @author - Hubert Borderiou
	 * If you give an in_id and no in_name, you get info concerning the category of id=in_id
	 * otherwise, you've got an category objet avec your in_id, in_name, in_descr
	 *
	 * @param int $in_id
	 * @param string $in_name
	 * @param string $in_description
	 */
	public function Testcategory($in_id=0, $in_name = '', $in_description="")
	{
		if ($in_id != 0 && $in_name == "") {
			$tmpobj = new Testcategory();
			$tmpobj->getCategory($in_id);
			$this->id = $tmpobj->id;
			$this->name = $tmpobj->name;
			$this->description = $tmpobj->description;
		} else {
			$this->id = $in_id;
			$this->name = $in_name;
			$this->description = $in_description;
		}
	}

	/**
	 * return the Testcategory object with id=in_id
	 * @param $in_id
	 */
	public function getCategory($in_id)
	{
		$t_cattable = Database::get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$in_id = intval($in_id);
		$sql = "SELECT * FROM $t_cattable
                WHERE id = $in_id AND c_id=".api_get_course_int_id();
		$res = Database::query($sql);
		$numrows = Database::num_rows($res);
		if ($numrows > 0) {
			$row = Database::fetch_array($res);
			$this->id = $row['id'];
			$this->name = $row['title'];
			$this->description  = $row['description'];
		}
	}

	/**
	 * add Testcategory in the database if name doesn't already exists
	 */
	public function addCategoryInBDD()
	{
		$t_cattable = Database :: get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$v_name = $this->name;
		$v_name = Database::escape_string($v_name);
		$v_description = $this->description;
		$v_description = Database::escape_string($v_description);
		// check if name already exists
		$sql = "SELECT count(*) AS nb FROM $t_cattable
              WHERE title = '$v_name' AND c_id=".api_get_course_int_id();
		$result_verif = Database::query($sql);
		$data_verif = Database::fetch_array($result_verif);
		// lets add in BDD if not the same name
		if ($data_verif['nb'] <= 0) {
			$c_id = api_get_course_int_id();
			$sql = "INSERT INTO $t_cattable VALUES ('$c_id', '', '$v_name', '$v_description')";
			Database::query($sql);
			$new_id = Database::insert_id();
			// add test_category in item_property table
			$course_code = api_get_course_id();
			$course_info = api_get_course_info($course_code);
			api_item_property_update(
                $course_info,
                TOOL_TEST_CATEGORY,
                $new_id,
                'TestCategoryAdded',
                api_get_user_id()
			);

			return $new_id;
		} else {

			return false;
		}
	}

	/**
	 * Removes the category from the database
	 * if there were question in this category, the link between question and category is removed
	 */
	public function removeCategory()
	{
		$t_cattable = Database :: get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$tbl_question_rel_cat = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
		$v_id = intval($this->id);
		$sql = "DELETE FROM $t_cattable WHERE id=$v_id AND c_id=".api_get_course_int_id();
		Database::query($sql);
		if (Database::affected_rows() <= 0) {
			return false;
		} else {
			// remove link between question and category
			$sql2 = "DELETE FROM $tbl_question_rel_cat WHERE category_id=$v_id AND c_id=".api_get_course_int_id();
			Database::query($sql2);
			// item_property update
			$course_code = api_get_course_id();
			$course_info = api_get_course_info($course_code);
			api_item_property_update($course_info, TOOL_TEST_CATEGORY, $this->id, 'TestCategoryDeleted', api_get_user_id());
			return true;
		}
	}

	/**
	 * Modify category name or description of category with id=in_id
	 */
	public function modifyCategory()
	{
		$t_cattable = Database :: get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$v_id = intval($this->id);
		$v_name = Database::escape_string($this->name);
		$v_description = Database::escape_string($this->description);
		$sql = "UPDATE $t_cattable SET title='$v_name', description='$v_description'
		        WHERE id = $v_id AND c_id=".api_get_course_int_id();
		Database::query($sql);
		if (Database::affected_rows() <= 0) {
			return false;
		} else {
			// item_property update
			$course_code = api_get_course_id();
			$course_info = api_get_course_info($course_code);
			api_item_property_update(
					$course_info,
					TOOL_TEST_CATEGORY,
					$this->id,
					'TestCategoryModified',
					api_get_user_id()
			);
			return true;
		}
	}

	/**
	 * Gets the number of question of category id=in_id
	 */
	public function getCategoryQuestionsNumber()
	{
		$t_reltable = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
		$in_id = intval($this->id);
		$sql = "SELECT count(*) AS nb FROM $t_reltable
		        WHERE category_id=$in_id AND c_id=".api_get_course_int_id();
		$res = Database::query($sql);
		$row = Database::fetch_array($res);
		return $row['nb'];
	}

	/**
	 * @param string $in_color
	 */
	public function display($in_color="#E0EBF5")
	{
		echo "<textarea style='background-color:$in_color; width:60%; height:100px;'>";
		print_r($this);
		echo "</textarea>";
	}


	/**
	 * Return an array of all Category objects in the database
	If in_field=="" Return an array of all category objects in the database
	Otherwise, return an array of all in_field value in the database (in_field = id or name or description)
	 */
	public static function getCategoryListInfo($in_field="", $in_courseid="")
	{
		if (empty($in_courseid) || $in_courseid=="") {
			$in_courseid = api_get_course_int_id();
		}
		$t_cattable = Database :: get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$in_field = Database::escape_string($in_field);
		$tabres = array();
		if ($in_field=="") {
			$sql = "SELECT * FROM $t_cattable WHERE c_id=$in_courseid ORDER BY title ASC";
			$res = Database::query($sql);
			while ($row = Database::fetch_array($res)) {
				$tmpcat = new Testcategory($row['id'], $row['title'], $row['description']);
				$tabres[] = $tmpcat;
			}
		} else {
			$sql = "SELECT $in_field FROM $t_cattable WHERE c_id=$in_courseid ORDER BY $in_field ASC";
			$res = Database::query($sql);
			while ($row = Database::fetch_array($res)) {
				$tabres[] = $row[$in_field];
			}
		}
		return $tabres;
	}

	/**
	 * Return the testcategory id for question with question_id = $in_questionid
	 * In this version, a question has only 1 testcategory.
	 * Return the testcategory id, 0 if none
	 * @param int $questionId
	 * @param int $courseId
	 *
	 * @return int
	 */
	public static function getCategoryForQuestion($questionId, $courseId ="")
	{
		$result = 0;
		if (empty($courseId) || $courseId=="") {
			$courseId = api_get_course_int_id();
		}
		$table = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
		$questionId = intval($questionId);
		$sql = "SELECT category_id FROM $table
		        WHERE question_id = $questionId AND c_id = $courseId";
		$res = Database::query($sql);
		if (Database::num_rows($res) > 0) {
			$data = Database::fetch_array($res);
			$result = $data['category_id'];
		}
		return $result;
	}

	/**
	 * true if question id has a category
	 */
	public static function isQuestionHasCategory($in_questionid)
	{
		if (Testcategory::getCategoryForQuestion($in_questionid) > 0) {
			return true;
		}
		return false;
	}

	/**
	Return the category name for question with question_id = $in_questionid
	In this version, a question has only 1 category.
	Return the category id, "" if none
	 */
	public static function getCategoryNameForQuestion($in_questionid, $in_courseid="")
	{
		if (empty($in_courseid) || $in_courseid=="") {
			$in_courseid = api_get_course_int_id();
		}
		$catid = Testcategory::getCategoryForQuestion($in_questionid, $in_courseid);
		$result = "";	// result
		$t_cattable = Database::get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$catid = intval($catid);
		$sql = "SELECT title FROM $t_cattable WHERE id = $catid  AND c_id = $in_courseid";
		$res = Database::query($sql);
		$data = Database::fetch_array($res);
		if (Database::num_rows($res) > 0) {
			$result = $data['title'];
		}
		return $result;
	}

	/**
	 * Return the list of differents categories ID for a test in the current course
	 * input : test_id
	 * return : array of category id (integer)
	 * hubert.borderiou 07-04-2011
	 * @param int $exerciseId
	 */
	public static function getListOfCategoriesIDForTest($exerciseId)
	{
		// parcourir les questions d'un test, recup les categories uniques dans un tableau
		$exercise = new Exercise();
		$exercise->read($exerciseId, false);
		$categoriesInExercise = $exercise->getQuestionWithCategories();

		$categories = array();
        if (!empty($categoriesInExercise)) {
			foreach ($categoriesInExercise as $category) {
				//$category['id'] = $category['iid'];
				$categories[$category['id']] = $category;
			}
		}

		return $categories;
	}

	/**
	 * @param Exercise $exercise_obj
	 * @return array
	 */
	public static function getListOfCategoriesIDForTestObject(Exercise $exercise_obj)
	{
		// parcourir les questions d'un test, recup les categories uniques dans un tableau
		$categories_in_exercise = array();
		// $question_list = $exercise_obj->getQuestionList();
		$question_list = $exercise_obj->getQuestionOrderedListByName();

		// the array given by selectQuestionList start at indice 1 and not at indice 0 !!! ???
		foreach ($question_list as $questionInfo) {
			$question_id = $questionInfo['question_id'];
			$category_list = Testcategory::getCategoryForQuestion($question_id);
			if (is_numeric($category_list)) {
				$category_list = array($category_list);
			}

			if (!empty($category_list)) {
				$categories_in_exercise = array_merge($categories_in_exercise, $category_list);
			}
		}
		if (!empty($categories_in_exercise)) {
			$categories_in_exercise = array_unique(array_filter($categories_in_exercise));
		}
		return $categories_in_exercise;
	}

	/**
	 * Return the list of differents categories NAME for a test
	 * @param int exercise id
	 * @param bool
	 * @return array of string
	 *
	 * @author function rewrote by jmontoya
	 */
	public static function getListOfCategoriesNameForTest($exercise_id, $grouped_by_category = true)
	{
		$result = array();
		$categories = self::getListOfCategoriesIDForTest($exercise_id, $grouped_by_category);

		foreach ($categories as $catInfo) {
			$categoryId = $catInfo['id'];
			if (!empty($categoryId)) {
				$result[$categoryId] = array(
                    'title' => $catInfo['title'],
                    //'parent_id' =>  $catInfo['parent_id'],
					'parent_id' => '',
                    'c_id' => $catInfo['c_id']
                );
			}
		}

		return $result;
	}

	/**
	 * @param Exercise $exercise_obj
	 * @return array
	 */
	public static function getListOfCategoriesForTest(Exercise $exercise_obj) {
		$result = array();
		$categories = self::getListOfCategoriesIDForTestObject($exercise_obj);
		foreach ($categories as $cat_id) {
			$cat = new Testcategory($cat_id);
			$cat = (array)$cat;
			$cat['iid'] = $cat['id'];
			$cat['title'] = $cat['name'];
			$result[$cat['id']] = $cat;
		}
		return $result;
	}

	/**
	 * return the number of differents categories for a test
	 * input : test_id
	 * return : integer
	 * hubert.borderiou 07-04-2011
	 */
	public static function getNumberOfCategoriesForTest($id)
	{
		return count(Testcategory::getListOfCategoriesIDForTest($id));
	}

	/**
	 * return the number of question of a category id in a test
	 * input : test_id, category_id
	 * return : integer
	 * hubert.borderiou 07-04-2011
	 */
	public static function getNumberOfQuestionsInCategoryForTest($in_testid, $in_categoryid)
	{
		$nbCatResult = 0;
		$quiz = new Exercise();
		$quiz->read($in_testid);
		$tabQuestionList = $quiz->selectQuestionList();
		// the array given by selectQuestionList start at indice 1 and not at indice 0 !!! ? ? ?
		for ($i=1; $i <= count($tabQuestionList); $i++) {
			if (isset($tabQuestionList[$i]) &&
                Testcategory::getCategoryForQuestion($tabQuestionList[$i]) == $in_categoryid
            ) {
				$nbCatResult++;
			}
		}
		return $nbCatResult;
	}

	/**
	 * return the number of question for a test using random by category
	 * input  : test_id, number of random question (min 1)
	 * hubert.borderiou 07-04-2011
	 * question without categories are not counted
	 */
	public static function getNumberOfQuestionRandomByCategory($in_testid, $in_nbrandom)
	{
		$nbquestionresult = 0;
		$tabcatid = Testcategory::getListOfCategoriesIDForTest($in_testid);
		for ($i=0; $i < count($tabcatid); $i++) {
            // 0 = no category for this question
			if (isset($tabcatid[$i]) && $tabcatid[$i] > 0) {

                $nbQuestionInThisCat = Testcategory::getNumberOfQuestionsInCategoryForTest(
                    $in_testid,
                    $tabcatid[$i]
                );
				if ($nbQuestionInThisCat > $in_nbrandom) {
					$nbquestionresult += $in_nbrandom;
				} else {
					$nbquestionresult += $nbQuestionInThisCat;
				}
			}
		}

		return $nbquestionresult;
	}

	/**
	 * Return an array (id=>name)
	 * tabresult[0] = get_lang('NoCategory');
	 *
	 */
	public static function getCategoriesIdAndName($in_courseid="")
	{
		if (empty($in_courseid) || $in_courseid=="") {
			$in_courseid = api_get_course_int_id();
		}
		$tabcatobject = Testcategory::getCategoryListInfo("", $in_courseid);
		$tabresult = array("0"=>get_lang('NoCategorySelected'));
		for ($i=0; $i < count($tabcatobject); $i++) {
			$tabresult[$tabcatobject[$i]->id] = $tabcatobject[$i]->name;
		}
		return $tabresult;
	}

    /**
     * Returns an array of question ids for each category
     * $categories[1][30] = 10, array with category id = 1 and question_id = 10
     * A question has "n" categories
     * @param int exercise
     * @param array $check_in_question_list
     * @param array $categoriesAddedInExercise
     *
     * @return array
     */
    static function getQuestionsByCat(
        $exerciseId,
        $check_in_question_list = array(),
        $categoriesAddedInExercise = array()
    ) {
        $tableQuestion = Database::get_course_table(TABLE_QUIZ_QUESTION);
        $TBL_EXERCICE_QUESTION = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
        $TBL_QUESTION_REL_CATEGORY = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
        $categoryTable = Database::get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
        $exerciseId = intval($exerciseId);
        $courseId = api_get_course_int_id();

        $sql = "SELECT DISTINCT qrc.question_id, qrc.category_id
                FROM $TBL_QUESTION_REL_CATEGORY qrc
                INNER JOIN $TBL_EXERCICE_QUESTION eq
                ON (eq.question_id = qrc.question_id)
                INNER JOIN $categoryTable c
                ON (c.id = qrc.category_id)
                INNER JOIN $tableQuestion q
                ON (q.id = qrc.question_id )
                WHERE
                  exercice_id = $exerciseId AND
                  qrc.c_id = ".$courseId."
                ";

        $res = Database::query($sql);
        $categories = array();
        while ($data = Database::fetch_array($res)) {
            if (!empty($check_in_question_list)) {
                if (!in_array($data['question_id'], $check_in_question_list)) {
                    continue;
                }
            }

            if (!isset($categories[$data['category_id']]) ||
                !is_array($categories[$data['category_id']])
            ) {
                $categories[$data['category_id']] = array();
            }

            $categories[$data['category_id']][] = $data['question_id'];
        }

        if (!empty($categoriesAddedInExercise)) {
            $newCategoryList = array();
            foreach ($categoriesAddedInExercise as $category) {
                $categoryId = $category['category_id'];
                if (isset($categories[$categoryId])) {
                    $newCategoryList[$categoryId] = $categories[$categoryId];
                }
            }

            $checkQuestionsWithNoCategory = false;
            foreach ($categoriesAddedInExercise as $category) {
                if (empty($category['category_id'])) {
                    // Check
                    $checkQuestionsWithNoCategory = true;
                    break;
                }
            }

            // Select questions that don't have any category related
            if ($checkQuestionsWithNoCategory) {
                $originalQuestionList = $check_in_question_list;
                foreach ($originalQuestionList as $questionId) {
                    $categoriesFlatten = array_flatten($categories);
                    if (!in_array($questionId, $categoriesFlatten)) {
                        $newCategoryList[0][] = $questionId;
                    }
                }
            }

            $categories = $newCategoryList;

        }

        return $categories;
    }

    /**
     * return a tab of $in_number random elements of $in_tab
     *
     * @param $in_tab
     * @param $in_number
     * @return array
     */
	public static function getNElementsFromArray($in_tab, $in_number)
	{
		$tabres = $in_tab;
		shuffle($tabres);
		if ($in_number < count($tabres)) {
			$tabres = array_slice($tabres, 0, $in_number);
		}
		return $tabres;
	}

	/**
	 * display the category
	 */
	public static function displayCategoryAndTitle($in_questionID, $in_display_category_name = 1)
	{
		echo self::returnCategoryAndTitle($in_questionID, $in_display_category_name);
	}

	/**
	 * @param $in_questionID
	 * @param int $in_display_category_name
	 * @return null|string
	 */
	public static function returnCategoryAndTitle($in_questionID, $in_display_category_name = 1) {
		$is_student = !(api_is_allowed_to_edit(null,true) || api_is_session_admin());
		// @todo fix $_SESSION['objExercise']
		$objExercise = isset($_SESSION['objExercise']) ? $_SESSION['objExercise'] : null;
		if (!empty($objExercise)) {
			$in_display_category_name = $objExercise->display_category_name;
		}
		$content = null;
		if (Testcategory::getCategoryNameForQuestion($in_questionID) != "" && ($in_display_category_name == 1 || !$is_student)) {
			$content .= '<div class="page-header">';
			$content .= '<h4>'.get_lang('Category').": ".Testcategory::getCategoryNameForQuestion($in_questionID).'</h4>';
			$content .= "</div>";
		}
		return $content;
	}

	/**
	 * Display signs [+] and/or (>0) after question title if question has options
	 * scoreAlwaysPositive and/or uncheckedMayScore
	 */
	public function displayQuestionOption($in_objQuestion)
	{
		if ($in_objQuestion->type == MULTIPLE_ANSWER && $in_objQuestion->scoreAlwaysPositive) {
			echo "<span style='font-size:75%'> (>0)</span>";
		}
		if ($in_objQuestion->type == MULTIPLE_ANSWER && $in_objQuestion->uncheckedMayScore) {
			echo "<span style='font-size:75%'> [+]</span>";
		}
	}

	/**
	 * sortTabByBracketLabel ($tabCategoryQuestions)
	 * key of $tabCategoryQuestions are the category id (0 for not in a category)
	 * value is the array of question id of this category
	 * Sort question by Category
	 */
	public static function sortTabByBracketLabel($in_tab)
	{
		$tabResult = array();
		$tabCatName = array();	// tab of category name
		while (list($cat_id, $tabquestion) = each($in_tab)) {
			$catTitle = new Testcategory($cat_id);
			$tabCatName[$cat_id] = $catTitle->name;
		}
		reset($in_tab);
		// sort table by value, keeping keys as they are
		asort($tabCatName);
		// keys of $tabCatName are keys order for $in_tab
		while (list($key, $val) = each($tabCatName)) {
			$tabResult[$key] = $in_tab[$key];
		}
		return $tabResult;
	}

	/**
	 * return total score for test exe_id for all question in the category $in_cat_id for user
	 * If no question for this category, return ""
	 */
	public static function getCatScoreForExeidForUserid($in_cat_id, $in_exe_id, $in_user_id)
	{
		$tbl_track_attempt		= Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
		$tbl_question_rel_category = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
		$in_cat_id = intval($in_cat_id);
		$in_exe_id = intval($in_exe_id);
		$in_user_id = intval($in_user_id);

		$query = "SELECT DISTINCT
		            marks, exe_id, user_id, ta.question_id, category_id
                  FROM $tbl_track_attempt ta , $tbl_question_rel_category qrc
                  WHERE
                    ta.question_id=qrc.question_id AND
                    qrc.category_id=$in_cat_id AND
                    exe_id=$in_exe_id AND user_id=$in_user_id";
		$res = Database::query($query);
		$totalcatscore = "";
		while ($data = Database::fetch_array($res)) {
			$totalcatscore += $data['marks'];
		}
		return $totalcatscore;
	}

	/**
	 * return the number max of question in a category
	 * count the number of questions in all categories, and return the max
	 * @author - hubert borderiou
	 */
	public static function getNumberMaxQuestionByCat($in_testid)
	{
		$res_num_max = 0;
		// foreach question
		$tabcatid = Testcategory::getListOfCategoriesIDForTest($in_testid);
		for ($i=0; $i < count($tabcatid); $i++) {
			if (isset($tabcatid[$i]) && $tabcatid[$i] > 0) {
                // 0 = no category for this question
                $nbQuestionInThisCat = Testcategory::getNumberOfQuestionsInCategoryForTest(
                    $in_testid,
                    $tabcatid[$i]
                );
				if ($nbQuestionInThisCat > $res_num_max) {
					$res_num_max = $nbQuestionInThisCat;
				}
			}
		}
		return $res_num_max;
	}

	/**
	 * Returns a category summary report
	 * @params int exercise id
	 * @params array pre filled array with the category_id, score, and weight
	 * example: array(1 => array('score' => '10', 'total' => 20));
	 */
	public static function get_stats_table_by_attempt($exercise_id, $category_list = array())
	{
		if (empty($category_list)) {
			return null;
		}
		$category_name_list = Testcategory::getListOfCategoriesNameForTest($exercise_id);

		$table = new HTML_Table(array('class' => 'data_table'));
		$table->setHeaderContents(0, 0, get_lang('Categories'));
		$table->setHeaderContents(0, 1, get_lang('AbsoluteScore'));
		$table->setHeaderContents(0, 2, get_lang('RelativeScore'));
		$row = 1;

		$none_category = array();
		if (isset($category_list['none'])) {
			$none_category = $category_list['none'];
			unset($category_list['none']);
		}

		$total = array();
		if (isset($category_list['total'])) {
			$total = $category_list['total'];
			unset($category_list['total']);
		}
		if (count($category_list) > 1) {
			foreach ($category_list as $category_id => $category_item) {
				$table->setCellContents($row, 0, $category_name_list[$category_id]);
				$table->setCellContents($row, 1, show_score($category_item['score'], $category_item['total'], false));
				$table->setCellContents($row, 2, show_score($category_item['score'], $category_item['total'], true, false, true));
				$row++;
			}

			if (!empty($none_category)) {
				$table->setCellContents($row, 0, get_lang('None'));
				$table->setCellContents($row, 1, show_score($none_category['score'], $none_category['total'], false));
				$table->setCellContents($row, 2, show_score($none_category['score'], $none_category['total'], true, false, true));
				$row++;
			}
			if (!empty($total)) {
				$table->setCellContents($row, 0, get_lang('Total'));
				$table->setCellContents($row, 1, show_score($total['score'], $total['total'], false));
				$table->setCellContents($row, 2, show_score($total['score'], $total['total'], true, false, true));
			}
			return $table->toHtml();
		}

		return null;
	}

	/**
	 * @return array
	 */
	function get_all_categories()
	{
		$table = Database::get_course_table(TABLE_QUIZ_CATEGORY);
		$sql = "SELECT * FROM $table ORDER BY title ASC";
		$res = Database::query($sql);
		while ($row = Database::fetch_array($res,'ASSOC')) {
			$array[] = $row;
		}
		return $array;
	}

	/**
	 * @param Exercise $exercise
	 * @param int $course_id
	 * @param string $order
	 * @param bool $shuffle
	 * @param bool $excludeCategoryWithNoQuestions
	 * @return array|bool
	 */
	public function getCategoryExerciseTree(
		$exercise,
		$course_id,
		$order = null,
		$shuffle = false,
		$excludeCategoryWithNoQuestions = true
	) {
        if (empty($exercise)) {
            return array();
        }

        if (!$exercise->specialCategoryOrders) {
            return false;
        }

        $course_id = intval($course_id);
		$table = Database::get_course_table(TABLE_QUIZ_REL_CATEGORY);
        $categoryTable = Database::get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$sql = "SELECT * FROM $table qc
              	LEFT JOIN $categoryTable c
                ON (qc.c_id = c.c_id AND c.id = qc.category_id)
                WHERE qc.c_id = $course_id AND exercise_id = {$exercise->id} ";

		if (!empty($order)) {
			$sql .= "ORDER BY $order";
		}

		$categories = array();

		$result = Database::query($sql);
		if (Database::num_rows($result)) {
			while ($row = Database::fetch_array($result, 'ASSOC')) {
				if ($excludeCategoryWithNoQuestions) {
					if ($row['count_questions'] == 0) {
						continue;
					}
				}
				if (empty($row['title']) && empty($row['category_id'])) {
					$row['title'] = get_lang('NoCategory');
				}
                $categories[$row['category_id']] = $row;
			}
		}

		if ($shuffle) {
			shuffle_assoc($categories);
		}

		return $categories;
	}

	public function getForm(& $form, $action = 'new')
	{
		switch($action) {
			case 'new':
				$header = get_lang('AddACategory');
				$submit = get_lang('AddTestCategory');
				break;
			case 'edit':
				$header = get_lang('EditCategory');
				$submit = get_lang('ModifyCategory');
				break;
		}

		// settting the form elements
		$form->addElement('header', $header);
		$form->addElement('hidden', 'category_id');
		$form->addElement('text', 'category_name', get_lang('CategoryName'), array('class' => 'span6'));
		$form->add_html_editor('category_description', get_lang('CategoryDescription'), false, false, array('ToolbarSet' => 'test_category', 'Width' => '90%', 'Height' => '200'));
		$category_parent_list = array();

		$options = array(
				'1' => get_lang('Visible'),
				'0' => get_lang('Hidden')
		);
		$form->addElement('select', 'visibility', get_lang('Visibility'), $options);
		$script = null;
		if (!empty($this->parent_id)) {
			$parent_cat = new Testcategory($this->parent_id);
			$category_parent_list = array($parent_cat->id => $parent_cat->name);
			$script .= '<script>$(function() { $("#parent_id").trigger("addItem",[{"title": "'.$parent_cat->name.'", "value": "'.$parent_cat->id.'"}]); });</script>';
		}
		$form->addElement('html', $script);

		$form->addElement('select', 'parent_id', get_lang('Parent'), $category_parent_list, array('id' => 'parent_id'));
		$form->addElement('style_submit_button', 'SubmitNote', $submit, 'class="add"');

		// setting the defaults
		$defaults = array();
		$defaults["category_id"] = $this->id;
		$defaults["category_name"] = $this->name;
		$defaults["category_description"] = $this->description;
		$defaults["parent_id"] = $this->parent_id;
		$defaults["visibility"] = $this->visibility;
		$form->setDefaults($defaults);

		// setting the rules
		$form->addRule('category_name', get_lang('ThisFieldIsRequired'), 'required');
	}

	/**
	 * Returns the category form.
	 * @param Exercise $exercise_obj
	 * @return string
	 */
	public function returnCategoryForm(Exercise $exercise_obj)
	{
		$categories = $this->getListOfCategoriesForTest($exercise_obj);

		$saved_categories = $exercise_obj->get_categories_in_exercise();
		$return = null;

		if (!empty($categories)) {
			$nbQuestionsTotal = $exercise_obj->getNumberQuestionExerciseCategory();
			$exercise_obj->setCategoriesGrouping(true);
			$real_question_count = count($exercise_obj->getQuestionList());

			$warning = null;
			if ($nbQuestionsTotal != $real_question_count) {
				$warning = Display::return_message(get_lang('CheckThatYouHaveEnoughQuestionsInYourCategories'), 'warning');
			}

			$return .= $warning;
			$return .= '<table class="data_table">';
			$return .= '<tr>';
			$return .= '<th height="24">' . get_lang('Categories') . '</th>';
			$return .= '<th width="70" height="24">' . get_lang('Number') . '</th></tr>';

			$emptyCategory = array(
				'id' => '0',
				'name' => get_lang('NoCategory'),
				'description' => '',
				'iid' => '0',
				'title' => get_lang('NoCategory')
			);

			$categories[] = $emptyCategory;

			foreach ($categories as $category) {
				$cat_id = $category['iid'];
				$return .= '<tr>';
				$return .= '<td>';
				//$return .= Display::div(isset($category['parent_path']) ? $category['parent_path'] : '');
				$return .= Display::div($category['name']);
				$return .= '</td>';
				$return .= '<td>';
				$value = isset($saved_categories) && isset($saved_categories[$cat_id]) ? $saved_categories[$cat_id]['count_questions'] : -1;
				$return .= '<input name="category['.$cat_id.']" value="' .$value.'" />';
				$return .= '</td>';
				$return .= '</tr>';
			}

			$return .= '</table>';
			$return .= get_lang('ZeroMeansNoQuestionWillBeSelectedMinusOneMeansThatAllQuestionsWillBeSelected');
			return $return;
		}
	}

	/**
	 * Sorts an array
	 * @param $array
	 * @return mixed
	 */
	public function sort_tree_array($array)
	{
		foreach ($array as $key => $row) {
			$parent[$key] = $row['parent_id'];
		}
		if (count($array) > 0) {
			array_multisort($parent, SORT_ASC, $array);
		}
		return $array;
	}

	/**
	 * Return true if a category already exists with the same name
	 * @param string $in_name
	 *
	 * @return bool
	 */
	public static function category_exists_with_title($in_name)
	{
		$tab_test_category = Testcategory::getCategoryListInfo("title");
		foreach ($tab_test_category as $title) {
			if ($title == $in_name) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Return the id of the test category with title = $in_title
	 * @param $in_title
	 * @param int $in_c_id
	 *
	 * @return int is id of test category
	 */
	public static function get_category_id_for_title($in_title, $in_c_id = 0)
	{
		$out_res = 0;
		if ($in_c_id == 0) {
			$in_c_id = api_get_course_int_id();
		}
		$tbl_cat = Database::get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$sql = "SELECT id FROM $tbl_cat WHERE c_id=$in_c_id AND title = '".Database::escape_string($in_title)."'";
		$res = Database::query($sql);
		if (Database::num_rows($res) > 0) {
			$data = Database::fetch_array($res);
			$out_res = $data['id'];
		}
		return $out_res;
	}

	/**
	 * Add a relation between question and category in table c_quiz_question_rel_category
	 * @param int $in_category_id
	 * @param int $in_question_id
	 * @param int $in_course_c_id
	 */
	public static function add_category_for_question_id($in_category_id, $in_question_id, $in_course_c_id)
	{
		$tbl_reltable = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
		// if question doesn't have a category
		// @todo change for 1.10 when a question can have several categories
		if (Testcategory::getCategoryForQuestion($in_question_id, $in_course_c_id) == 0 && $in_question_id > 0 && $in_course_c_id > 0) {
			$sql = "INSERT INTO $tbl_reltable VALUES (".intval($in_course_c_id).", ".intval($in_question_id).", ".intval($in_category_id).")";
			Database::query($sql);
		}
	}

	/**
	 * @param int $courseId
	 * @param int $sessionId
	 *
	 * @return array
	 */
	public function getCategories($courseId, $sessionId = 0)
	{
		$table = Database::get_course_table(TABLE_QUIZ_QUESTION_CATEGORY);
		$itemProperty = Database::get_course_table(TABLE_ITEM_PROPERTY);
		$sessionId = intval($sessionId);
		$courseId = intval($courseId);

		if (empty($sessionId)) {
			$sessionCondition = api_get_session_condition($sessionId, true, false, 'i.id_session');
		} else {
			$sessionCondition = api_get_session_condition($sessionId, true, true, 'i.id_session');
		}

		if (empty($courseId)) {
			return array();
		}

		$sql = "SELECT c.* FROM $table c
                INNER JOIN $itemProperty i
                ON c.c_id = i.c_id AND i.ref = c.id
                WHERE
                    c.c_id = $courseId AND
                    i.tool = '".TOOL_TEST_CATEGORY."'
                    $sessionCondition
                ORDER BY title";
		$result = Database::query($sql);

		return Database::store_result($result, 'ASSOC');
	}

	/**
	 * @param int $courseId
	 * @param int $sessionId
	 * @return string
	 */
	public function displayCategories($courseId, $sessionId = 0)
	{
		$categories = $this->getCategories($courseId, $sessionId);
		$html = null;

		foreach ($categories as $category) {
			$tmpobj = new Testcategory($category['id']);
			$nb_question = $tmpobj->getCategoryQuestionsNumber();
			$rowname = self::protectJSDialogQuote($category['title']);
			$nb_question_label = $nb_question == 1 ? $nb_question . ' ' . get_lang('Question') : $nb_question . ' ' . get_lang('Questions');

			$html .= '<div class="sectiontitle" id="id_cat' . $category['id'] . '">';
			$html .= "<span style='float:right'>" . $nb_question_label . "</span>";
			$html .= $category['title'];
			$html .= '</div>';
			$html .= '<div class="sectioncomment">';
			$html .= $category['description'];
			$html .= '</div>';
			$html .= '<div>';
			$html .= '<a href="' . api_get_self() . '?action=editcategory&amp;category_id=' . $category['id'] . '">' .
					Display::return_icon('edit.png', get_lang('Edit'), array(), ICON_SIZE_SMALL) . '</a>';
			$html .= ' <a href="' . api_get_self() . '?action=deletecategory&amp;category_id=' . $category['id'] . '" ';
			$html .= 'onclick="return confirmDelete(\'' . self::protectJSDialogQuote(get_lang('DeleteCategoryAreYouSure') . '[' . $rowname) . '] ?\', \'id_cat' . $category['id'] . '\');">';
			$html .= Display::return_icon('delete.png', get_lang('Delete'), array(), ICON_SIZE_SMALL) . '</a>';
			$html .= '</div>';
		}

		return $html;
	}

	// To allowed " in javascript dialog box without bad surprises
	// replace " with two '
	public function protectJSDialogQuote($in_txt)
	{
		$res = $in_txt;
		$res = str_replace("'", "\'", $res);
		$res = str_replace('"', "\'\'", $res); // super astuce pour afficher les " dans les boite de dialogue
		return $res;
	}
}