chamilo-lms/main/exercice/question.class.php

<?php
/* For licensing terms, see /license.txt */
/**
*	File containing the Question class.
*	@package chamilo.exercise
* 	@author Olivier Brouckaert
*   @author Julio Montoya <gugli100@gmail.com> lot of bug fixes
*   Modified by hubert.borderiou@grenet.fr - add question categories
*/
/**
 * Code
 */

if(!class_exists('Question')):

// answer types
define('UNIQUE_ANSWER',                             1);
define('MULTIPLE_ANSWER',                           2);
define('FILL_IN_BLANKS',                            3);
define('MATCHING',                                  4);
define('FREE_ANSWER',                               5);
define('HOT_SPOT',                                  6);
define('HOT_SPOT_ORDER',                            7);
define('HOT_SPOT_DELINEATION',                      8);
define('MULTIPLE_ANSWER_COMBINATION',               9);
define('UNIQUE_ANSWER_NO_OPTION',                   10);
define('MULTIPLE_ANSWER_TRUE_FALSE',                11);
define('MULTIPLE_ANSWER_COMBINATION_TRUE_FALSE',    12);
define('ORAL_EXPRESSION',                           13);
define('GLOBAL_MULTIPLE_ANSWER',                    14);

//Some alias used in the QTI exports
define('MCUA',				1);
define('TF',				1);
define('MCMA',				2);
define('FIB',				3);

if (!class_exists('Category')) include_once("testcategory.class.php");

/**
	QUESTION CLASS
 *
 *	This class allows to instantiate an object of type Question
 *
 *	@author Olivier Brouckaert, original author
 *	@author Patrick Cool, LaTeX support
*	@package chamilo.exercise
 */
abstract class Question
{
	public $id;
	public $question;
	public $description;
	public $weighting;
	public $position;
	public $type;
	public $level;
	public $picture;
	public $exerciseList;  // array with the list of exercises which this question is in
	public $category;
	private $isContent;
    public $course;        
	static $typePicture = 'new_question.png';
	static $explanationLangVar = '';
    
	static $questionTypes = array(
                                UNIQUE_ANSWER => 				array('unique_answer.class.php' , 	'UniqueAnswer'),
                                MULTIPLE_ANSWER => 				array('multiple_answer.class.php' , 'MultipleAnswer'),										
								GLOBAL_MULTIPLE_ANSWER =>		array('global_multiple_answer.class.php' , 'GlobalMultipleAnswer'),			
								FILL_IN_BLANKS => 				array('fill_blanks.class.php' , 	'FillBlanks'),
                                MATCHING => 					array('matching.class.php' , 		'Matching'),
                                FREE_ANSWER => 					array('freeanswer.class.php' , 		'FreeAnswer'),
                                ORAL_EXPRESSION => 				array('oral_expression.class.php' , 'OralExpression'),
                                HOT_SPOT => 					array('hotspot.class.php' , 		'HotSpot'),
                                HOT_SPOT_DELINEATION =>         array('hotspot.class.php' , 'HotspotDelineation'),
                                MULTIPLE_ANSWER_COMBINATION =>	array('multiple_answer_combination.class.php' , 'MultipleAnswerCombination'),
                                UNIQUE_ANSWER_NO_OPTION =>      array('unique_answer_no_option.class.php' ,   'UniqueAnswerNoOption'),
                                MULTIPLE_ANSWER_TRUE_FALSE =>   array('multiple_answer_true_false.class.php' , 'MultipleAnswerTrueFalse'),
                                MULTIPLE_ANSWER_COMBINATION_TRUE_FALSE =>   array('multiple_answer_combination_true_false.class.php' , 'MultipleAnswerCombinationTrueFalse')                            
							);

	/**
	 * constructor of the class
	 *
	 * @author - Olivier Brouckaert
	 */
	public function Question() {
		$this->id=0;
		$this->question='';
		$this->description='';
		$this->weighting=0;
		$this->position=1;
		$this->picture='';
		$this->level = 1;
		$this->category=0;
        $this->extra=''; // This variable is used when loading an exercise like an scenario with an special hotspot: final_overlap, final_missing, final_excess
		$this->exerciseList=array();
		$this->course = api_get_course_info();
	}

	public function getIsContent() {
	    $isContent = null;
	    if (isset($_REQUEST['isContent'])) {
		    $isContent = intval($_REQUEST['isContent']);
	    }
		return $this->isContent = $isContent;
	}

	/**
	 * Reads question informations from the data base
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $id - question ID
	 * @return - boolean - true if question exists, otherwise false
	 */
	static function read($id, $course_id = null) {
        $id = intval($id);	
        
        if (!empty($course_id)) {            
            $course_info =  api_get_course_info_by_id($course_id);
        } else {            
            $course_info = api_get_course_info();
        }        
        
        $course_id = $course_info['real_id'];

		$TBL_QUESTIONS         = Database::get_course_table(TABLE_QUIZ_QUESTION);
		$TBL_EXERCICE_QUESTION = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
        
		$sql = "SELECT question,description,ponderation,position,type,picture,level,extra FROM $TBL_QUESTIONS WHERE c_id = $course_id AND id = $id ";
        
		$result = Database::query($sql);

		// if the question has been found
		if ($object = Database::fetch_object($result)) {
			
			$objQuestion 				= Question::getInstance($object->type);
            if (!empty($objQuestion)) {
			
                $objQuestion->id			= $id;
                $objQuestion->question		= $object->question;
                $objQuestion->description	= $object->description;
                $objQuestion->weighting		= $object->ponderation;
                $objQuestion->position		= $object->position;
                $objQuestion->type			= $object->type;
                $objQuestion->picture		= $object->picture;
                $objQuestion->level			= (int) $object->level;
                $objQuestion->extra         = $object->extra;
                $objQuestion->course        = $course_info;
                $objQuestion->category	    = Testcategory::getCategoryForQuestion($id);

                $sql = "SELECT exercice_id FROM $TBL_EXERCICE_QUESTION WHERE c_id = $course_id AND question_id = $id";
                $result_exercise_list = Database::query($sql);

                // fills the array with the exercises which this question is in
                if ($result_exercise_list) {
                    while ($obj = Database::fetch_object($result_exercise_list)) {
                        $objQuestion->exerciseList[] = $obj->exercice_id;
                    }
                }
                return $objQuestion;
            }
		}
		// question not found
		return false;
	}

	/**
	 * returns the question ID
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - question ID
	 */
	function selectId() {
		return $this->id;
	}

	/**
	 * returns the question title
	 *
	 * @author - Olivier Brouckaert
	 * @return - string - question title
	 */
	function selectTitle() {
		$this->question=text_filter($this->question);
		return $this->question;
	}

	/**
	 * returns the question description
	 *
	 * @author - Olivier Brouckaert
	 * @return - string - question description
	 */
	function selectDescription() {
		$this->description=text_filter($this->description);
		return $this->description;
	}

	/**
	 * returns the question weighting
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - question weighting
	 */
	function selectWeighting()
	{
		return $this->weighting;
	}

	/**
	 * returns the question position
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - question position
	 */
	function selectPosition() {
		return $this->position;
	}

	/**
	 * returns the answer type
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - answer type
	 */
	function selectType() {
		return $this->type;
	}

	/**
	 * returns the level of the question
	 *
	 * @author - Nicolas Raynaud
	 * @return - integer - level of the question, 0 by default.
	 */
	function selectLevel() {
		return $this->level;
	}

	/**
	 * returns the picture name
	 *
	 * @author - Olivier Brouckaert
	 * @return - string - picture name
	 */
	function selectPicture() {
		return $this->picture;
	}
    
    function selectPicturePath() {
        if (!empty($this->picture)) {
            return api_get_path(WEB_COURSE_PATH).$this->course['path'].'/document/images/'.$this->picture;
        }
        return false;        
    }

	/**
	 * returns the array with the exercise ID list
	 *
	 * @author - Olivier Brouckaert
	 * @return - array - list of exercise ID which the question is in
	 */
	function selectExerciseList() {
		return $this->exerciseList;
	}

	/**
	 * returns the number of exercises which this question is in
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - number of exercises
	 */
	function selectNbrExercises() {
		return sizeof($this->exerciseList);
	}

	/**
	 * changes the question title
	 *
	 * @author - Olivier Brouckaert
	 * @param - string $title - question title
	 */
	function updateTitle($title) {
		$this->question=$title;
	}

	/**
	 * changes the question description
	 *
	 * @author - Olivier Brouckaert
	 * @param - string $description - question description
	 */
	function updateDescription($description) {
		$this->description=$description;
	}

	/**
	 * changes the question weighting
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $weighting - question weighting
	 */
	function updateWeighting($weighting) {
		$this->weighting=$weighting;
	}


	/**
	 * @author - Hubert Borderiou 12-10-2011
	 * @param - array of category $in_category
	 */
	function updateCategory($in_category) {
		$this->category=$in_category;
	}
	
	/**
	 * @author - Hubert Borderiou 12-10-2011
	 * @param - interger $in_positive
	 */
	function updateScoreAlwaysPositive($in_positive) {
		$this->scoreAlwaysPositive=$in_positive;
	}
	
	/**
	 * @author - Hubert Borderiou 12-10-2011
	 * @param - interger $in_positive
	 */
	function updateUncheckedMayScore($in_positive) {
		$this->uncheckedMayScore=$in_positive;
	}
	
	/**
	 * @author - Hubert Borderiou 12-10-2011
	 * @param - interger $in_positive
	 * in this version, a question can only have 1 category
	 * if category is 0, then question has no category then delete the category entry
	 */
	function saveCategory($in_category) {
		if ($in_category <= 0) {
			$this->deleteCategory();
		} else {
            // update or add category for a question
            
			$TBL_QUESTION_REL_CATEGORY = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
			$category_id = Database::escape_string($in_category);
			$question_id = Database::escape_string($this->id);
			$sql = "SELECT count(*) AS nb FROM $TBL_QUESTION_REL_CATEGORY WHERE question_id=$question_id AND c_id=".api_get_course_int_id();
			$res = Database::query($sql);
			$row = Database::fetch_array($res);
			if ($row['nb'] > 0){
				$sql = "UPDATE $TBL_QUESTION_REL_CATEGORY SET category_id=$category_id WHERE question_id=$question_id AND c_id=".api_get_course_int_id();
				$res = Database::query($sql);
			} else {
				$sql = "INSERT INTO $TBL_QUESTION_REL_CATEGORY VALUES (".api_get_course_int_id().", $question_id, $category_id)";
				$res = Database::query($sql);
			}
		}
	}	
	
	/**
	 * @author hubert borderiou 12-10-2011
	 * delete any category entry for question id
	 * @param : none
	 * delte the category for question
	 */
	function deleteCategory() {
		$TBL_QUESTION_REL_CATEGORY = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
		$question_id = Database::escape_string($this->id);
	 	$sql = "DELETE FROM $TBL_QUESTION_REL_CATEGORY WHERE question_id=$question_id AND c_id=".api_get_course_int_id();
	 	$res = Database::query($sql);
	}
	

	/**
	 * changes the question position
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $position - question position
	 */
	function updatePosition($position) {
		$this->position=$position;
	}

	/**
	 * changes the question level
	 *
	 * @author - Nicolas Raynaud
	 * @param - integer $level - question level
	 */
	function updateLevel($level) {
		$this->level=$level;
	}

	/**
	 * changes the answer type. If the user changes the type from "unique answer" to "multiple answers"
	 * (or conversely) answers are not deleted, otherwise yes
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $type - answer type
	 */
	function updateType($type) {
		$TBL_REPONSES           = Database::get_course_table(TABLE_QUIZ_ANSWER);
        $course_id              = $this->course['real_id'];
        
        if (empty($course_id)) {
            $course_id = api_get_course_int_id();
        }
		// if we really change the type
		if($type != $this->type) {
			// if we don't change from "unique answer" to "multiple answers" (or conversely)
			if(!in_array($this->type,array(UNIQUE_ANSWER,MULTIPLE_ANSWER)) || !in_array($type,array(UNIQUE_ANSWER,MULTIPLE_ANSWER))) {
				// removes old answers
				$sql="DELETE FROM $TBL_REPONSES WHERE c_id = $course_id  AND question_id='".Database::escape_string($this->id)."'";
				Database::query($sql);
			}

			$this->type=$type;
		}
	}

	/**
	 * adds a picture to the question
	 *
	 * @author - Olivier Brouckaert
	 * @param - string $Picture - temporary path of the picture to upload
	 * @param - string $PictureName - Name of the picture
	 * @return - boolean - true if uploaded, otherwise false
	 */
	function uploadPicture($Picture,$PictureName) {
		global $picturePath;

		if (!file_exists($picturePath)) {
			if (mkdir($picturePath, api_get_permissions_for_new_directories())) {
				// document path
				$documentPath = api_get_path(SYS_COURSE_PATH) . $this->course['path'] . "/document";
				$path = str_replace($documentPath,'',$picturePath);
				$title_path = basename($picturePath);
				$doc_id = add_document($this->course, $path, 'folder', 0,$title_path);
				api_item_property_update($this->course, TOOL_DOCUMENT, $doc_id, 'FolderCreated', api_get_user_id());
			}
		}

		// if the question has got an ID
		if ($this->id) {
			$extension = pathinfo($PictureName, PATHINFO_EXTENSION);						
			$this->picture = 'quiz-'.$this->id.'.jpg';						    			
    		$o_img = new Image($Picture);
    		$o_img->send_image($picturePath.'/'.$this->picture, -1, 'jpg');
            $document_id = add_document($this->course, '/images/'.$this->picture, 'file', filesize($picturePath.'/'.$this->picture),$this->picture);
    	    if ($document_id) {
                return api_item_property_update($this->course, TOOL_DOCUMENT, $document_id, 'DocumentAdded', api_get_user_id());
            }
		}

		return false;
	}

	/**
	 * Resizes a picture || Warning!: can only be called after uploadPicture, or if picture is already available in object.
	 *
	 * @author - Toon Keppens
	 * @param - string $Dimension - Resizing happens proportional according to given dimension: height|width|any
	 * @param - integer $Max - Maximum size
	 * @return - boolean - true if success, false if failed
	 */
	function resizePicture($Dimension, $Max) {
		global $picturePath;

		// if the question has an ID
		if($this->id) {
	  		// Get dimensions from current image.
	  		$my_image = new Image($picturePath.'/'.$this->picture);
	  		
	  		$current_image_size = $my_image->get_image_size();
	  		$current_width      = $current_image_size['width'];
	  		$current_height     = $current_image_size['height'];		

			if($current_width < $Max && $current_height <$Max)
				return true;
			elseif($current_height == "")
				return false;

			// Resize according to height.
			if ($Dimension == "height") {
				$resize_scale = $current_height / $Max;
				$new_height = $Max;
				$new_width = ceil($current_width / $resize_scale);
			}

			// Resize according to width
			if ($Dimension == "width") {
				$resize_scale = $current_width / $Max;
				$new_width = $Max;
				$new_height = ceil($current_height / $resize_scale);
			}

			// Resize according to height or width, both should not be larger than $Max after resizing.
			if ($Dimension == "any") {
				if ($current_height > $current_width || $current_height == $current_width)
				{
					$resize_scale = $current_height / $Max;
					$new_height = $Max;
					$new_width = ceil($current_width / $resize_scale);
				}
				if ($current_height < $current_width)
				{
					$resize_scale = $current_width / $Max;
					$new_width = $Max;
					$new_height = ceil($current_height / $resize_scale);
				}
			}
			
            $my_image->resize($new_width, $new_height);
            $result = $my_image->send_image($picturePath.'/'.$this->picture);
            
			if ($result) {
				return true;
			} else {
				return false;
			}
		}


	}

	/**
	 * deletes the picture
	 *
	 * @author - Olivier Brouckaert
	 * @return - boolean - true if removed, otherwise false
	 */
	function removePicture() {
		global $picturePath;

		// if the question has got an ID and if the picture exists
		if($this->id) {
			$picture=$this->picture;
			$this->picture='';

			return @unlink($picturePath.'/'.$picture)?true:false;
		}

		return false;
	}

	/**
	 * Exports a picture to another question
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $questionId - ID of the target question
	 * @return - boolean - true if copied, otherwise false
	 */
	function exportPicture($questionId, $course_info) {
		$course_id          = $course_info['real_id'];
        $TBL_QUESTIONS      = Database::get_course_table(TABLE_QUIZ_QUESTION);
        $destination_path   = api_get_path(SYS_COURSE_PATH).$course_info['path'].'/document/images';
        $source_path        = api_get_path(SYS_COURSE_PATH).$this->course['path'].'/document/images';        

		// if the question has got an ID and if the picture exists
		if ($this->id && !empty($this->picture)) {
			$picture=explode('.',$this->picture);
			$extension = $picture[sizeof($picture)-1];
			$picture = 'quiz-'.$questionId.'.'.$extension;			          
			$result = @copy($source_path.'/'.$this->picture, $destination_path.'/'.$picture) ? true : false;
            //If copy was correct then add to the database
            if ($result) {
                $sql = "UPDATE $TBL_QUESTIONS SET picture='".Database::escape_string($picture)."' WHERE c_id = $course_id AND id='".intval($questionId)."'";
                Database::query($sql);            
            
                $document_id = add_document($course_info, '/images/'.$picture, 'file', filesize($destination_path.'/'.$picture), $picture);
                if ($document_id) {
                    return api_item_property_update($course_info, TOOL_DOCUMENT, $document_id, 'DocumentAdded', api_get_user_id());
                }
            }
            
            return $result;
		}        
		return false;
	}

	/**
	 * Saves the picture coming from POST into a temporary file
	 * Temporary pictures are used when we don't want to save a picture right after a form submission.
	 * For example, if we first show a confirmation box.
	 *
	 * @author - Olivier Brouckaert
	 * @param - string $Picture - temporary path of the picture to move
	 * @param - string $PictureName - Name of the picture
	 */
	function setTmpPicture($Picture,$PictureName) {
		global $picturePath;
		$PictureName = explode('.',$PictureName);
		$Extension = $PictureName[sizeof($PictureName)-1];

		// saves the picture into a temporary file
		@move_uploaded_file($Picture,$picturePath.'/tmp.'.$Extension);
	}

	/**
		Sets the title
	*/
	public function setTitle($title) {
		$this->question = $title;
	}
    
    /**
        Sets the title
    */
    public function setExtra($extra) {
        $this->extra = $extra;
    }

	/**
	 * Moves the temporary question "tmp" to "quiz-$questionId"
	 * Temporary pictures are used when we don't want to save a picture right after a form submission.
	 * For example, if we first show a confirmation box.
	 *
	 * @author - Olivier Brouckaert
	 * @return - boolean - true if moved, otherwise false
	 */
	function getTmpPicture() {
		global $picturePath;

		// if the question has got an ID and if the picture exists
		if ($this->id) {
			if (file_exists($picturePath.'/tmp.jpg')) {
				$Extension='jpg';
			} elseif(file_exists($picturePath.'/tmp.gif')) {
				$Extension='gif';
			} elseif(file_exists($picturePath.'/tmp.png')) {
				$Extension='png';
			}
			$this->picture='quiz-'.$this->id.'.'.$Extension;
			return @rename($picturePath.'/tmp.'.$Extension,$picturePath.'/'.$this->picture)?true:false;
		}
		return false;
	}

	/**
	 * updates the question in the data base
	 * if an exercise ID is provided, we add that exercise ID into the exercise list
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $exerciseId - exercise ID if saving in an exercise
	 */
	function save($exerciseId=0) {
		$TBL_EXERCICE_QUESTION	= Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
		$TBL_QUESTIONS			= Database::get_course_table(TABLE_QUIZ_QUESTION);

		$id				= $this->id;
		$question		= $this->question;
		$description	= $this->description;
		$weighting		= $this->weighting;
		$position		= $this->position;
		$type			= $this->type;
		$picture		= $this->picture;
		$level			= $this->level;
        $extra			= $this->extra;
        $c_id 			= $this->course['real_id'];
        $category       = $this->category;
     
    
		// question already exists
		if(!empty($id)) {
			$sql="UPDATE $TBL_QUESTIONS SET
					question 	='".Database::escape_string($question)."',
					description	='".Database::escape_string($description)."',
					ponderation	='".Database::escape_string($weighting)."',
					position	='".Database::escape_string($position)."',
					type		='".Database::escape_string($type)."',
					picture		='".Database::escape_string($picture)."',
                    extra       ='".Database::escape_string($extra)."',
					level		='".Database::escape_string($level)."'
				WHERE c_id = $c_id  AND id='".Database::escape_string($id)."'";
			Database::query($sql);
			$this->saveCategory($category);
			if (!empty($exerciseId)) {
				api_item_property_update($this->course, TOOL_QUIZ, $id,'QuizQuestionUpdated',api_get_user_id());
			}
            if (api_get_setting('search_enabled')=='true') {
                if ($exerciseId != 0) {
                    $this -> search_engine_edit($exerciseId);
                } else {
                    /**
                    * actually there is *not* an user interface for
                    * creating questions without a relation with an exercise
                    */
                }
            }
		} else {
			// creates a new question
			$sql	= "SELECT max(position) FROM $TBL_QUESTIONS as question, $TBL_EXERCICE_QUESTION as test_question 
					   WHERE 	question.id					= test_question.question_id AND 
								test_question.exercice_id	= '".Database::escape_string($exerciseId)."' AND
								question.c_id 				= $c_id AND
								test_question.c_id 			= $c_id ";
			$result	= Database::query($sql);
			$current_position = Database::result($result,0,0);
			$this->updatePosition($current_position+1);
			$position = $this->position;
			$sql = "INSERT INTO $TBL_QUESTIONS (c_id, question, description, ponderation, position, type, picture, extra, level) VALUES ( 
					$c_id,
					'".Database::escape_string($question)."',
					'".Database::escape_string($description)."',
					'".Database::escape_string($weighting)."',
					'".Database::escape_string($position)."',
					'".Database::escape_string($type)."',
					'".Database::escape_string($picture)."',
					'".Database::escape_string($extra)."',
                    '".Database::escape_string($level)."'
					)";			
			Database::query($sql);

			$this->id = Database::insert_id();

			api_item_property_update($this->course, TOOL_QUIZ, $this->id,'QuizQuestionAdded',api_get_user_id());

			// If hotspot, create first answer
			if ($type == HOT_SPOT || $type == HOT_SPOT_ORDER) {
				$TBL_ANSWERS = Database::get_course_table(TABLE_QUIZ_ANSWER);
				$sql = "INSERT INTO $TBL_ANSWERS (c_id, id, question_id , answer , correct , comment , ponderation , position , hotspot_coordinates , hotspot_type ) 
					    VALUES (".$c_id.", '1', '".Database::escape_string($this->id)."', '', NULL , '', '10' , '1', '0;0|0|0', 'square')";
				Database::query($sql);
            }
            
			if ($type == HOT_SPOT_DELINEATION ) {
				$TBL_ANSWERS = Database::get_course_table(TABLE_QUIZ_ANSWER);
				$sql="INSERT INTO $TBL_ANSWERS (c_id, id, question_id , answer , correct , comment , ponderation , position , hotspot_coordinates , hotspot_type ) 
					  VALUES (".$c_id.", '1', '".Database::escape_string($this->id)."', '', NULL , '', '10' , '1', '0;0|0|0', 'delineation')";
				Database::query($sql);
			}
			
            if (api_get_setting('search_enabled')=='true') {
                if ($exerciseId != 0) {
                    $this -> search_engine_edit($exerciseId, TRUE);
                } else {
                    /**
                    * actually there is *not* an user interface for
                    * creating questions without a relation with an exercise
                    */
                }
            }
		}

		// if the question is created in an exercise
		if ($exerciseId) {
			/*
			$sql = 'UPDATE '.Database::get_course_table(TABLE_LP_ITEM).'
					SET max_score = '.intval($weighting).'
					WHERE item_type = "'.TOOL_QUIZ.'"
					AND path='.intval($exerciseId);
			Database::query($sql);
			*/
			// adds the exercise into the exercise list of this question
			$this->addToList($exerciseId, TRUE);
		}
	}

    function search_engine_edit($exerciseId, $addQs=FALSE, $rmQs=FALSE) {
        // update search engine and its values table if enabled
        if (api_get_setting('search_enabled')=='true' && extension_loaded('xapian')) {
            $course_id = api_get_course_id();
            // get search_did
            $tbl_se_ref = Database::get_main_table(TABLE_MAIN_SEARCH_ENGINE_REF);
            if ($addQs || $rmQs) {
                //there's only one row per question on normal db and one document per question on search engine db
                $sql = 'SELECT * FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_second_level=%s LIMIT 1';
                $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_QUIZ, $this->id);
            } else {
              $sql = 'SELECT * FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_high_level=%s AND ref_id_second_level=%s LIMIT 1';
              $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_QUIZ, $exerciseId, $this->id);
            }
            $res = Database::query($sql);

            if (Database::num_rows($res) > 0 || $addQs) {
                require_once(api_get_path(LIBRARY_PATH) . 'search/DokeosIndexer.class.php');
                require_once(api_get_path(LIBRARY_PATH) . 'search/IndexableChunk.class.php');

                $di = new DokeosIndexer();
                if ($addQs) {
                	$question_exercises = array((int)$exerciseId);
                } else {
                    $question_exercises = array();
                }
                isset($_POST['language'])? $lang=Database::escape_string($_POST['language']): $lang = 'english';
                $di->connectDb(NULL, NULL, $lang);

                // retrieve others exercise ids
                $se_ref = Database::fetch_array($res);
                $se_doc = $di->get_document((int)$se_ref['search_did']);
                if ($se_doc !== FALSE) {
	                if ( ($se_doc_data=$di->get_document_data($se_doc)) !== FALSE ) {
		                $se_doc_data = unserialize($se_doc_data);
		                if (isset($se_doc_data[SE_DATA]['type']) && $se_doc_data[SE_DATA]['type'] == SE_DOCTYPE_EXERCISE_QUESTION) {
			                if (isset($se_doc_data[SE_DATA]['exercise_ids']) && is_array($se_doc_data[SE_DATA]['exercise_ids'])) {
                                foreach ($se_doc_data[SE_DATA]['exercise_ids'] as $old_value) {
                                    if (!in_array($old_value, $question_exercises)) {
                                    	$question_exercises[] = $old_value;
                                    }
                                }
			                }
		                }
	                }
                }
                if ($rmQs) {
                	while ( ($key=array_search($exerciseId, $question_exercises)) !== FALSE) {
                		unset($question_exercises[$key]);
                	}
                }

                // build the chunk to index
                $ic_slide = new IndexableChunk();
                $ic_slide->addValue("title", $this->question);
                $ic_slide->addCourseId($course_id);
                $ic_slide->addToolId(TOOL_QUIZ);
                $xapian_data = array(
                    SE_COURSE_ID => $course_id,
                    SE_TOOL_ID => TOOL_QUIZ,
                    SE_DATA => array('type' => SE_DOCTYPE_EXERCISE_QUESTION, 'exercise_ids' => $question_exercises, 'question_id' => (int)$this->id),
                    SE_USER => (int)api_get_user_id(),
                );
                $ic_slide->xapian_data = serialize($xapian_data);
                $ic_slide->addValue("content", $this->description);

                //TODO: index answers, see also form validation on question_admin.inc.php

                $di->remove_document((int)$se_ref['search_did']);
                $di->addChunk($ic_slide);

                //index and return search engine document id
                if (!empty($question_exercises)) { // if empty there is nothing to index
                	$did = $di->index();
                    unset($di);
                }
                if ($did || $rmQs) {
                    // save it to db
                    if ($addQs || $rmQs) {
                    	$sql = 'DELETE FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_second_level=\'%s\'';
                        $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_QUIZ, $this->id);
                    } else {
                        $sql = 'DELETE FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_high_level=\'%s\' AND ref_id_second_level=\'%s\'';
                        $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_QUIZ, $exerciseId, $this->id);
                    }
                    Database::query($sql);
                    if ($rmQs) {
                        if (!empty($question_exercises)) {
                          $sql = 'INSERT INTO %s (id, course_code, tool_id, ref_id_high_level, ref_id_second_level, search_did)
                              VALUES (NULL , \'%s\', \'%s\', %s, %s, %s)';
                          $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_QUIZ, array_shift($question_exercises), $this->id, $did);
                          Database::query($sql);
                        }
                    } else {
                        $sql = 'INSERT INTO %s (id, course_code, tool_id, ref_id_high_level, ref_id_second_level, search_did)
                            VALUES (NULL , \'%s\', \'%s\', %s, %s, %s)';
                        $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_QUIZ, $exerciseId, $this->id, $did);
                        Database::query($sql);
                    }
                }

            }
        }

    }

	/**
	 * adds an exercise into the exercise list
	 *
	 * @author - Olivier Brouckaert
     * @param - integer $exerciseId - exercise ID
     * @param - boolean $fromSave - comming from $this->save() or not
	 */
	function addToList($exerciseId, $fromSave = false) {
		$TBL_EXERCICE_QUESTION = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
		$id = $this->id;
		// checks if the exercise ID is not in the list
		if (!in_array($exerciseId,$this->exerciseList)) {            
			$this->exerciseList[]=$exerciseId;            
            $new_exercise = new Exercise();
            $new_exercise->read($exerciseId);
            $count = $new_exercise->selectNbrQuestions();
            $count++;
			$sql="INSERT INTO $TBL_EXERCICE_QUESTION (c_id, question_id, exercice_id, question_order) VALUES 
				 ({$this->course['real_id']}, '".Database::escape_string($id)."','".Database::escape_string($exerciseId)."', '$count' )";
			Database::query($sql);
            
            // we do not want to reindex if we had just saved adnd indexed the question
            if (!$fromSave) {
            	$this->search_engine_edit($exerciseId, TRUE);
            }
		}
	}

	/**
	 * removes an exercise from the exercise list
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $exerciseId - exercise ID
	 * @return - boolean - true if removed, otherwise false
	 */
	function removeFromList($exerciseId) {
		global $TBL_EXERCICE_QUESTION;

		$id = $this->id;

		// searches the position of the exercise ID in the list
		$pos=array_search($exerciseId,$this->exerciseList);
        
        $course_id = api_get_course_int_id();

		// exercise not found
		if($pos === false) {
			return false;
		} else {
			// deletes the position in the array containing the wanted exercise ID
			unset($this->exerciseList[$pos]);
            //update order of other elements
            $sql = "SELECT question_order FROM $TBL_EXERCICE_QUESTION WHERE c_id = $course_id AND question_id='".Database::escape_string($id)."' AND exercice_id='".Database::escape_string($exerciseId)."'";
            $res = Database::query($sql);
            if (Database::num_rows($res)>0) {
                $row = Database::fetch_array($res);
                if (!empty($row['question_order'])) {
                    $sql = "UPDATE $TBL_EXERCICE_QUESTION SET question_order = question_order-1 
                            WHERE c_id = $course_id AND exercice_id='".Database::escape_string($exerciseId)."' AND question_order > ".$row['question_order'];
                    $res = Database::query($sql);
                }
            }

			$sql="DELETE FROM $TBL_EXERCICE_QUESTION WHERE c_id = $course_id AND question_id='".Database::escape_string($id)."' AND exercice_id='".Database::escape_string($exerciseId)."'";
			Database::query($sql);

			return true;
		}
	}

	/**
	 * Deletes a question from the database
	 * the parameter tells if the question is removed from all exercises (value = 0),
	 * or just from one exercise (value = exercise ID)
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $deleteFromEx - exercise ID if the question is only removed from one exercise
	 */
	function delete($deleteFromEx=0) {		       
        $course_id = api_get_course_int_id();

		$TBL_EXERCICE_QUESTION	= Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
		$TBL_QUESTIONS			= Database::get_course_table(TABLE_QUIZ_QUESTION);
		$TBL_REPONSES           = Database::get_course_table(TABLE_QUIZ_ANSWER);
		$TBL_QUIZ_QUESTION_REL_CATEGORY = Database::get_course_table(TABLE_QUIZ_QUESTION_REL_CATEGORY);
		
		$id=$this->id;

		// if the question must be removed from all exercises
		if(!$deleteFromEx) {
            //update the question_order of each question to avoid inconsistencies
            $sql = "SELECT exercice_id, question_order FROM $TBL_EXERCICE_QUESTION WHERE c_id = $course_id AND question_id='".Database::escape_string($id)."'";
            $res = Database::query($sql);
            if (Database::num_rows($res)>0) {
                while ($row = Database::fetch_array($res)) {
                    if (!empty($row['question_order'])) {
                        $sql = "UPDATE $TBL_EXERCICE_QUESTION SET question_order = question_order-1 WHERE c_id = $course_id AND exercice_id='".Database::escape_string($row['exercice_id'])."' AND question_order > ".$row['question_order'];
                        $res = Database::query($sql);
                    }
                }
            }
			$sql="DELETE FROM $TBL_EXERCICE_QUESTION WHERE c_id = $course_id AND question_id='".Database::escape_string($id)."'";
			Database::query($sql);

			$sql="DELETE FROM $TBL_QUESTIONS WHERE c_id = $course_id AND id='".Database::escape_string($id)."'";
			Database::query($sql);

			$sql="DELETE FROM $TBL_REPONSES WHERE c_id = $course_id AND question_id='".Database::escape_string($id)."'";
			Database::query($sql);

			// remove the category of this question in the question_rel_category table
			$sql = "DELETE FROM $TBL_QUIZ_QUESTION_REL_CATEGORY WHERE c_id = $course_id AND question_id='".Database::escape_string($id)."' AND c_id=".api_get_course_int_id();
			Database::query($sql);
			
			api_item_property_update($this->course, TOOL_QUIZ, $id,'QuizQuestionDeleted',api_get_user_id());
			$this->removePicture();

			// resets the object
			$this->Question();
		} else {
            // just removes the exercise from the list            
			$this->removeFromList($deleteFromEx);
            if (api_get_setting('search_enabled')=='true' && extension_loaded('xapian')) {
                // disassociate question with this exercise
                $this -> search_engine_edit($deleteFromEx, FALSE, TRUE);
            }
            api_item_property_update($this->course, TOOL_QUIZ, $id,'QuizQuestionDeleted',api_get_user_id());
		}
	}

	/**
	 * Duplicates the question
	 *
	 * @author Olivier Brouckaert
     * @param  array   Course info of the destination course
	 * @return int     ID of the new question
    */
     
	function duplicate($course_info = null) {        
        if (empty($course_info)) {
        	$course_info = $this->course;
        } else {
        	$course_info = $course_info;
        }
        $TBL_QUESTIONS        = Database::get_course_table(TABLE_QUIZ_QUESTION);
        $TBL_QUESTION_OPTIONS = Database::get_course_table(TABLE_QUIZ_QUESTION_OPTION);

		$question     = $this->question;
		$description  = $this->description;
		$weighting    = $this->weighting;
		$position     = $this->position;
		$type         = $this->type;
		$level        = intval($this->level);
        $extra        = $this->extra;
        
        //Using the same method used in the course copy to transform URLs
        
        if ($this->course['id'] != $course_info['id']) {
            $description  = DocumentManager::replace_urls_inside_content_html_from_copy_course($description, $this->course['id'], $course_info['id']);
            $question     = DocumentManager::replace_urls_inside_content_html_from_copy_course($question, $this->course['id'], $course_info['id']);
        }
        
        $course_id = $course_info['real_id'];
        
        //Read the source options
        $options = self::readQuestionOption($this->id, $this->course['real_id']);
                
        //Inserting in the new course db / or the same course db
		$sql = "INSERT INTO $TBL_QUESTIONS (c_id, question, description, ponderation, position, type, level, extra ) 
				VALUES('$course_id', '".Database::escape_string($question)."','".Database::escape_string($description)."','".Database::escape_string($weighting)."','".Database::escape_string($position)."','".Database::escape_string($type)."' ,'".Database::escape_string($level)."' ,'".Database::escape_string($extra)."'  )";
		Database::query($sql);    
            
		$new_question_id = Database::insert_id();        
        
        if (!empty($options)) {
            //Saving the quiz_options      
            foreach ($options as $item) {
                $item['question_id'] 	= $new_question_id;
                $item['c_id'] 			= $course_id;
                unset($item['id']); 
                Database::insert($TBL_QUESTION_OPTIONS, $item);	
            }
        }
        
		// Duplicates the picture of the hotspot
		$this->exportPicture($new_question_id, $course_info);
		return $new_question_id;
	}

    function get_question_type_name() {
        $key = self::$questionTypes[$this->type];
        return get_lang($key[1]);
    }
    
    function get_question_type($type) {
        if ($type == ORAL_EXPRESSION && api_get_setting('enable_nanogong') != 'true') {
            return null;
        }        
        return self::$questionTypes[$type];
    }
    
    function get_question_type_list() {
        if (api_get_setting('enable_nanogong') != 'true') {
            self::$questionTypes[ORAL_EXPRESSION] = null;
            unset(self::$questionTypes[ORAL_EXPRESSION]);
        }   
        return self::$questionTypes;
    }

	/**
	 * Returns an instance of the class corresponding to the type
	 * @param integer $type the type of the question
	 * @return an instance of a Question subclass (or of Questionc class by default)
	 */
	static function getInstance($type) {
		if (!is_null($type)) {            
			list($file_name, $class_name) = self::get_question_type($type);
            if (!empty($file_name)) {
                include_once $file_name;
                if (class_exists($class_name)) {
                    return new $class_name();
                } else {
                    echo 'Can\'t instanciate class '.$class_name.' of type '.$type;                   
                }
            }
		}
        return null;
	}

	/**
	 * Creates the form to create / edit a question
	 * A subclass can redifine this function to add fields...
	 * @param FormValidator $form the formvalidator instance (by reference)
	 */
	function createForm (&$form, $fck_config=0) {
		echo '	<style>					
					.media { display:none;}
				</style>';
		echo '<script>
			// hack to hide http://cksource.com/forums/viewtopic.php?f=6&t=8700

			function FCKeditor_OnComplete( editorInstance )
			{
			   if (document.getElementById ( \'HiddenFCK\' + editorInstance.Name )) {
			      HideFCKEditorByInstanceName (editorInstance.Name);
			   }
			}

			function HideFCKEditorByInstanceName ( editorInstanceName ) {
			   if (document.getElementById ( \'HiddenFCK\' + editorInstanceName ).className == "HideFCKEditor" ) {
			      document.getElementById ( \'HiddenFCK\' + editorInstanceName ).className = "media";
			      }
			}

			function show_media()
			{
				var my_display = document.getElementById(\'HiddenFCKquestionDescription\').style.display;
				if(my_display== \'none\' || my_display == \'\') {
				document.getElementById(\'HiddenFCKquestionDescription\').style.display = \'block\';
				document.getElementById(\'media_icon\').innerHTML=\'&nbsp;<img style="vertical-align: middle;" src="../img/looknfeelna.png" alt="" />&nbsp;'.get_lang('EnrichQuestion').'\';
			} else {
				document.getElementById(\'HiddenFCKquestionDescription\').style.display = \'none\';
				document.getElementById(\'media_icon\').innerHTML=\'&nbsp;<img style="vertical-align: middle;" src="../img/looknfeel.png" alt="" />&nbsp;'.get_lang('EnrichQuestion').'\';
			}
		}
		
		// hub 13-12-2010
		function visiblerDevisibler(in_id) {
			if (document.getElementById(in_id)) {
				if (document.getElementById(in_id).style.display == "none") {
					document.getElementById(in_id).style.display = "block";
					if (document.getElementById(in_id+"Img")) {
						document.getElementById(in_id+"Img").src = "../img/div_hide.gif";
					}
				}
				else {
					document.getElementById(in_id).style.display = "none";
					if (document.getElementById(in_id+"Img")) {
						document.getElementById(in_id+"Img").src = "../img/div_show.gif";
					}
				}
			}
		}		
		</script>';
        
		// question name
		$form->addElement('text', 'questionName', get_lang('Question'), array('class' => 'span6'));		        
		$form->addRule('questionName', get_lang('GiveQuestion'), 'required');

		// default content
		$isContent = isset($_REQUEST['isContent']) ? intval($_REQUEST['isContent']) : null;

		// question type
		$answerType= intval($_REQUEST['answerType']);
		$form->addElement('hidden','answerType',$_REQUEST['answerType']);

		// html editor
		$editor_config = array('ToolbarSet' => 'TestQuestionDescription', 'Width' => '100%', 'Height' => '150');
		if(is_array($fck_config)){
			$editor_config = array_merge($editor_config, $fck_config);
		}
		if(!api_is_allowed_to_edit(null,true)) $editor_config['UserStatus'] = 'student';

		$form->addElement('advanced_settings','
			<a href="javascript://" onclick=" return show_media()"><span id="media_icon"><img style="vertical-align: middle;" src="../img/looknfeel.png" alt="" />&nbsp;'.get_lang('EnrichQuestion').'</span></a>		
		');

		$form -> addElement ('html','<div class="HideFCKEditor" id="HiddenFCKquestionDescription" >');
		$form->add_html_editor('questionDescription', get_lang('langQuestionDescription'), false, false, $editor_config);
		$form -> addElement ('html','</div>');

		// Advanced parameters
		$form->addElement('advanced_settings','<a href="javascript:void(0)" onclick="visiblerDevisibler(\'id_advancedOption\')"><img id="id_advancedOptionImg" style="vertical-align:middle;" src="../img/div_show.gif" alt="" />&nbsp;'.get_lang("AdvancedParameters").'</a>');
        
		$select_level = array (1=>1,2=>2,3=>3,4=>4,5=>5);	
        
        $form->addElement('html','<div id="id_advancedOption" style="display:none;">');
        
        $form->addElement('select', 'questionLevel',get_lang('Difficulty'), $select_level);
        
		// categories
		$tabCat = array();
		$tabCat = Testcategory::getCategoriesIdAndName(); 
		$form->addElement('select', 'questionCategory', get_lang('Category'), $tabCat);
		
		// hidden values
		$form->addElement('hidden','myid',$_REQUEST['myid']);
        
        if (!isset($_GET['fromExercise'])) {            
            switch($answerType) {
                case 1:	$this->question = get_lang('langDefaultUniqueQuestion'); break;
                case 2:	$this->question = get_lang('langDefaultMultipleQuestion'); break;
                case 3:	$this->question = get_lang('langDefaultFillBlankQuestion'); break;
                case 4:	$this->question = get_lang('langDefaultMathingQuestion'); break;
                case 5:	$this->question = get_lang('langDefaultOpenQuestion');	break;
                case 9:	$this->question = get_lang('langDefaultMultipleQuestion'); break;
            }
        }
        
		$form->addElement('html','</div>');
        
		// default values
		$defaults = array();		
		$defaults['questionName']           = $this -> question;
		$defaults['questionDescription']    = $this -> description;
		$defaults['questionLevel']          = $this -> level;
		$defaults['questionCategory']       = $this->category;
		
        //Came from he question pool        
        if (isset($_GET['fromExercise'])) {   
            $form->setDefaults($defaults);   
        }

		if (!empty($_REQUEST['myid'])) {
			$form->setDefaults($defaults);
		} else {
			if ($isContent == 1) {
				$form->setDefaults($defaults);
			}
		}        
	}
    

	/**
	 * function which process the creation of questions
	 * @param FormValidator $form the formvalidator instance
	 * @param Exercise $objExercise the Exercise instance
	 */
	function processCreation ($form, $objExercise) {
		$this -> updateTitle($form->getSubmitValue('questionName'));
		$this -> updateDescription($form->getSubmitValue('questionDescription'));
		$this -> updateLevel($form->getSubmitValue('questionLevel'));
		$this->updateCategory($form->getSubmitValue('questionCategory'));
		$this -> save($objExercise -> id);
		// modify the exercise
		$objExercise->addToList($this -> id);
		$objExercise->update_question_positions();
	}

	/**
	 * abstract function which creates the form to create / edit the answers of the question
	 * @param the formvalidator instance
	 */
	abstract function createAnswersForm ($form);

	/**
	 * abstract function which process the creation of answers
	 * @param the formvalidator instance
	 */
	abstract function processAnswersCreation ($form);


	/**
	 * Displays the menu of question types
	 */
	static function display_type_menu ($feedback_type = 0) {
		global $exerciseId;
        $course_id = api_get_course_int_id();
        
		// 1. by default we show all the question types
		$question_type_custom_list = self::get_question_type_list();

		if (!isset($feedback_type)) $feedback_type=0;
		if ($feedback_type==1) {
			//2. but if it is a feedback DIRECT we only show the UNIQUE_ANSWER type that is currently available
			//$question_type_custom_list = array ( UNIQUE_ANSWER => self::$questionTypes[UNIQUE_ANSWER]);
			$question_type_custom_list = array ( UNIQUE_ANSWER => self::$questionTypes[UNIQUE_ANSWER],HOT_SPOT_DELINEATION => self::$questionTypes[HOT_SPOT_DELINEATION]);  
		} else {
			unset($question_type_custom_list[HOT_SPOT_DELINEATION]);
		}

		//blocking edition

		$show_quiz_edition = true;
		if (isset($exerciseId) && !empty($exerciseId)) {
			$TBL_LP_ITEM	= Database::get_course_table(TABLE_LP_ITEM);
			$sql="SELECT max_score FROM $TBL_LP_ITEM
				  WHERE c_id = $course_id AND item_type = '".TOOL_QUIZ."' AND path ='".Database::escape_string($exerciseId)."'";
			$result = Database::query($sql);
			if (Database::num_rows($result) > 0) {
				$show_quiz_edition = false;
			}
		}

		echo '<ul class="question_menu">';

		foreach ($question_type_custom_list as $i=>$a_type) {
			// include the class of the type
			require_once($a_type[0]);
            // get the picture of the type and the langvar which describes it
            $img = $explanation = '';
			eval('$img = '.$a_type[1].'::$typePicture;');
			eval('$explanation = get_lang('.$a_type[1].'::$explanationLangVar);');
			echo '<li>';
			echo '<div class="icon_image_content">';
			if ($show_quiz_edition) {
				echo '<a href="admin.php?'.api_get_cidreq().'&newQuestion=yes&answerType='.$i.'">'.Display::return_icon($img, $explanation).'</a>';
				//echo '<br>';
				//echo '<a href="admin.php?'.api_get_cidreq().'&newQuestion=yes&answerType='.$i.'">'.$explanation.'</a>';
			} else {
				$img = pathinfo($img);
				$img = $img['filename'];
				echo ''.Display::return_icon($img.'_na.gif',$explanation).'';
				//echo '<br>';
				//echo ''.$explanation.'';
			}
			echo '</div>';
			echo '</li>';
		}

		echo '<li>';
		echo '<div class="icon_image_content">';
		if ($show_quiz_edition) {
			if ($feedback_type==1) {
				echo $url = '<a href="question_pool.php?'.api_get_cidreq().'&type=1&fromExercise='.$exerciseId.'">';
			} else {
				echo $url = '<a href="question_pool.php?'.api_get_cidreq().'&fromExercise='.$exerciseId.'">';
			}
			echo Display::return_icon('database.png', get_lang('GetExistingQuestion'), '');
		} else {
			echo Display::return_icon('database_na.png', get_lang('GetExistingQuestion'), '');
		}	
		echo '</a>';
		echo '</div></li>';
		echo '</ul>';
	}
    
    static function saveQuestionOption($question_id, $name, $course_id, $position = 0) {
        $TBL_EXERCICE_QUESTION_OPTION    = Database::get_course_table(TABLE_QUIZ_QUESTION_OPTION);   
        $params['question_id']  = intval($question_id);
        $params['name']         = $name;        
        $params['position']     = $position;
        $params['c_id']         = $course_id;                   
        $result  = self::readQuestionOption($question_id, $course_id);
        $last_id = Database::insert($TBL_EXERCICE_QUESTION_OPTION, $params);
        return $last_id; 
    }
    
    static function deleteAllQuestionOptions($question_id, $course_id) {
    	$TBL_EXERCICE_QUESTION_OPTION    = Database::get_course_table(TABLE_QUIZ_QUESTION_OPTION);
        Database::delete($TBL_EXERCICE_QUESTION_OPTION, array('c_id = ? AND question_id = ?'=> array($course_id, $question_id)));
    }
    
    static function updateQuestionOption($id, $params, $course_id) {
        $TBL_EXERCICE_QUESTION_OPTION    = Database::get_course_table(TABLE_QUIZ_QUESTION_OPTION);
        $result = Database::update($TBL_EXERCICE_QUESTION_OPTION, $params, array('c_id = ? AND id = ?'=>array($course_id, $id)));             
        return $result;        
    }
    
    
    static function readQuestionOption($question_id, $course_id) {
        $TBL_EXERCICE_QUESTION_OPTION    = Database::get_course_table(TABLE_QUIZ_QUESTION_OPTION);               
        $result = Database::select('*', $TBL_EXERCICE_QUESTION_OPTION, array('where'=>array('c_id = ? AND question_id = ?' =>array($course_id, $question_id)), 'order'=>'id ASC'));
        return $result;        
    }
    
	function return_header($feedback_type = null, $counter = null) {
	    $counter_label = '';
	    if (!empty($counter)) {
	        $counter_label = intval($counter);
	    }	
	    echo Display::div(get_lang("Question").' '.($counter_label).' : '.$this->question, array('id'=>'question_title', 'class'=>'sectiontitle'));
	    echo Display::div($this->description, array('id'=>'question_description'));	    
	}
    /**
     * Create a question from a set of parameters
     * @param   int     Quiz ID
     * @param   string  Question name
     * @param   int     Maximum result for the question
     * @param   int     Type of question (see constants at beginning of question.class.php)
     * @param   int     Question level/category
     */
    function create_question ($quiz_id, $question_name, $max_score = 0, $type = 1, $level = 1) {
        $course_id = api_get_course_int_id();
        
        $tbl_quiz_question = Database::get_course_table(TABLE_QUIZ_QUESTION);
        $tbl_quiz_rel_question = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
        
        $quiz_id = intval($quiz_id);
        $max_score = (float) $max_score;
        $type = intval($type);
        $level = intval($level);
        
        // Get the max position
        $sql = "SELECT max(position) as max_position"
               ." FROM $tbl_quiz_question q INNER JOIN $tbl_quiz_rel_question r"
               ." ON q.id = r.question_id"
               ." AND exercice_id = $quiz_id AND q.c_id = $course_id AND r.c_id = $course_id";
        $rs_max = Database::query($sql, __FILE__, __LINE__);
        $row_max = Database::fetch_object($rs_max);
        $max_position = $row_max->max_position +1;
   
        // Insert the new question
        $sql = "INSERT INTO $tbl_quiz_question (c_id, question, ponderation, position, type, level) 
                VALUES ($course_id, '".Database::escape_string($question_name)."', '$max_score', $max_position, $type, $level)";
        $rs = Database::query($sql);
        // Get the question ID
        $question_id = Database::get_last_insert_id();
        
        // Get the max question_order
        $sql = "SELECT max(question_order) as max_order "
              ."FROM $tbl_quiz_rel_question WHERE c_id = $course_id AND exercice_id = $quiz_id ";
        $rs_max_order = Database::query($sql);
        $row_max_order = Database::fetch_object($rs_max_order);
        $max_order = $row_max_order->max_order + 1;
        // Attach questions to quiz
        $sql = "INSERT INTO $tbl_quiz_rel_question "
              ."(c_id, question_id,exercice_id,question_order)"
              ." VALUES($course_id, $question_id, $quiz_id, $max_order)";
        $rs = Database::query($sql);
        return $question_id;
    }
    
    /**
     * return the image filename of the question type
     *
    */
    public function get_type_icon_html() {
    	$type            = $this->selectType();        
    	$tabQuestionList = Question::get_question_type_list(); // [0]=file to include [1]=type name
        
    	require_once $tabQuestionList[$type][0];
			eval('$img = '.$tabQuestionList[$type][1].'::$typePicture;');
			eval('$explanation = get_lang('.$tabQuestionList[$type][1].'::$explanationLangVar);');
			return array($img, $explanation);
    }
}
endif;