chamilo-lms2/main/gradebook/lib/be/learnpathlink.class.php

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

/**
 * Defines a gradebook LearnpathLink object.
 * @author Yannick Warnier <yannick.warnier@beeznest.com>
 * @author Bert Steppé
 * @package chamilo.gradebook
 */
class LearnpathLink extends AbstractLink
{
    private $course_info = null;
    private $learnpath_table = null;
    private $learnpath_data = null;

    /**
     * Constructor
     */
    public function __construct()
    {
        parent::__construct();
        $this->set_type(LINK_LEARNPATH);
    }

    /**
     * Generate an array of learnpaths that a teacher hasn't created a link for.
     * @return array 2-dimensional array - every element contains 2 subelements (id, name)
     */
    public function get_not_created_links()
    {
        return false;
        if (empty($this->course_code)) {
            die('Error in get_not_created_links() : course code not set');
        }

        $tbl_grade_links = Database::get_main_table(TABLE_MAIN_GRADEBOOK_LINK);

        $sql = 'SELECT id, name FROM ' . $this->get_learnpath_table() . ' lp
				WHERE c_id = ' . $this->course_id . ' AND id NOT IN '
            . ' (SELECT ref_id FROM ' . $tbl_grade_links
            . ' WHERE type = ' . LINK_LEARNPATH
            . " AND course_code = '" . $this->get_course_code() . "'"
            . ') AND lp.session_id=' . api_get_session_id() . '';

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

        $cats = array();
        while ($data = Database::fetch_array($result)) {
            $cats[] = array($data['id'], $data['name']);
        }

        return $cats;
    }

    /**
     * Generate an array of all learnpaths available.
     * @return array 2-dimensional array - every element contains 2 subelements (id, name)
     */
    public function get_all_links()
    {
        if (empty($this->course_code)) {
            die('Error in get_not_created_links() : course code not set');
        }

        $session_id = api_get_session_id();
        if (empty($session_id)) {
            $session_condition = api_get_session_condition(0, true);
        } else {
            $session_condition = api_get_session_condition($session_id, true, true);
        }

        $sql = 'SELECT id, name FROM ' . $this->get_learnpath_table() . '
                WHERE c_id = ' . $this->course_id . ' ' . $session_condition . ' ';
        $result = Database::query($sql);

        $cats = array();
        while ($data = Database::fetch_array($result)) {
            $cats[] = array($data['id'], $data['name']);
        }

        return $cats;
    }


    /**
     * Has anyone used this learnpath yet ?
     */
    public function has_results()
    {
        $tbl_stats = Database::get_course_table(TABLE_LP_VIEW);
        $sql = "SELECT count(id) AS number FROM $tbl_stats
				WHERE c_id = " . $this->course_id . " AND lp_id = " . $this->get_ref_id();
        $result = Database::query($sql);
        $number = Database::fetch_array($result, 'NUM');
        return ($number[0] != 0);
    }

    /**
     * Get the progress of this learnpath. Only the last attempt are taken into account.
     * @param $stud_id student id (default: all students who have results - then the average is returned)
     * @return    array (score, max) if student is given
     *            array (sum of scores, number of scores) otherwise
     *            or null if no scores available
     */
    public function calc_score($stud_id = null, $type = null)
    {
        $tbl_stats = Database::get_course_table(TABLE_LP_VIEW);
        $session_id = api_get_session_id();

        $sql = "SELECT * FROM $tbl_stats
                WHERE
                	c_id = " . $this->course_id . " AND
                    lp_id = " . $this->get_ref_id() . " AND
                    session_id = $session_id ";

        if (isset($stud_id)) {
            $sql .= ' AND user_id = ' . intval($stud_id);
        }

        // order by id, that way the student's first attempt is accessed first
        $sql .= ' ORDER BY view_count DESC';

        $scores = Database::query($sql);
        // for 1 student
        if (isset($stud_id)) {
            if ($data = Database::fetch_assoc($scores)) {
                return array($data['progress'], 100);
            } else {
                return null;
            }
        } else {
            // all students -> get average
            $students = array();  // user list, needed to make sure we only
            // take first attempts into account
            $rescount = 0;
            $sum = 0;
            $bestResult = 0;
            $sumResult = 0;
            while ($data = Database::fetch_array($scores)) {
                if (!(array_key_exists($data['user_id'], $students))) {
                    $students[$data['user_id']] = $data['progress'];
                    $rescount++;
                    $sum += $data['progress'] / 100;
                    $sumResult += $data['progress'];

                    if ($data['progress'] > $bestResult) {
                        $bestResult = $data['progress'];
                    }
                }
            }

            if ($rescount == 0) {
                return null;
            } else {

                switch ($type) {
                    case 'best':
                        return array($bestResult, 100);
                        break;
                    case 'average':
                        return array($sumResult / $rescount, 100);
                        break;
                    case 'ranking':
                        return AbstractLink::getCurrentUserRanking($stud_id, $students);
                        break;
                    default:
                        return array($sum, $rescount);
                        break;
                }
            }
        }
    }

    /**
     * Get URL where to go to if the user clicks on the link.
     */
    public function get_link()
    {
        $session_id = api_get_session_id();
        $url = api_get_path(WEB_CODE_PATH) . 'lp/lp_controller.php?' . api_get_cidreq_params($this->get_course_code(),
                $session_id) . '&gradebook=view';

        if (!api_is_allowed_to_edit() || $this->calc_score(api_get_user_id()) == null) {
            $url .= '&action=view&lp_id=' . $this->get_ref_id();
        } else {
            $url .= '&action=build&lp_id=' . $this->get_ref_id();
        }
        return $url;
    }

    /**
     * Get name to display: same as learnpath title
     */
    public function get_name()
    {
        $data = $this->get_learnpath_data();
        return $data['name'];
    }

    /**
     * Get description to display: same as learnpath description
     */
    public function get_description()
    {
        $data = $this->get_learnpath_data();
        return $data['description'];
    }

    /**
     * Check if this still links to a learnpath
     */
    public function is_valid_link()
    {
        $sql = 'SELECT count(id) FROM ' . $this->get_learnpath_table() . '
                WHERE c_id = ' . $this->course_id . ' AND id = ' . $this->get_ref_id() . ' ';
        $result = Database::query($sql);
        $number = Database::fetch_row($result, 'NUM');
        return ($number[0] != 0);
    }

    public function get_type_name()
    {
        return get_lang('LearningPaths');
    }

    public function needs_name_and_description()
    {
        return false;
    }

    public function needs_max()
    {
        return false;
    }

    public function needs_results()
    {
        return false;
    }

    public function is_allowed_to_change_name()
    {
        return false;
    }

    // INTERNAL FUNCTIONS

    /**
     * Lazy load function to get the database table of the learnpath
     */
    private function get_learnpath_table()
    {
        $this->learnpath_table = Database::get_course_table(TABLE_LP_MAIN);
        return $this->learnpath_table;
    }

    /**
     * Lazy load function to get the database contents of this learnpath
     */
    private function get_learnpath_data()
    {
        if (!isset($this->learnpath_data)) {
            $sql = 'SELECT * FROM ' . $this->get_learnpath_table() . '
                    WHERE c_id = ' . $this->course_id . ' AND id = ' . $this->get_ref_id() . ' ';
            $result = Database::query($sql);
            $this->learnpath_data = Database::fetch_array($result);
        }
        return $this->learnpath_data;
    }

    public function get_icon_name()
    {
        return 'learnpath';
    }
}