class.assMultipleChoice.php

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<?php
/* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */

require_once './Modules/TestQuestionPool/classes/class.assQuestion.php';
require_once './Modules/Test/classes/inc.AssessmentConstants.php';
require_once './Modules/TestQuestionPool/interfaces/interface.ilObjQuestionScoringAdjustable.php';
require_once './Modules/TestQuestionPool/interfaces/interface.ilObjAnswerScoringAdjustable.php';
require_once './Modules/TestQuestionPool/interfaces/interface.iQuestionCondition.php';
require_once './Modules/TestQuestionPool/classes/class.ilUserQuestionResult.php';

class assMultipleChoice extends assQuestion implements ilObjQuestionScoringAdjustable, ilObjAnswerScoringAdjustable, iQuestionCondition
{
        var $answers;

        var $output_type;

        public $isSingleline;
        public $lastChange;
        public $feedback_setting;

        protected $thumb_size;

        public function setIsSingleline($isSingleline)
        {
                $this->isSingleline = $isSingleline;
        }

        public function getIsSingleline()
        {
                return $this->isSingleline;
        }

        public function setLastChange($lastChange)
        {
                $this->lastChange = $lastChange;
        }

        public function getLastChange()
        {
                return $this->lastChange;
        }

        public function __construct(
                $title = "",
                $comment = "",
                $author = "",
                $owner = -1,
                $question = "",
                $output_type = OUTPUT_ORDER
        )
        {
                parent::__construct($title, $comment, $author, $owner, $question);
                $this->output_type = $output_type;
                $this->thumb_size = 150;
                $this->answers = array();
                $this->shuffle = 1;
        }

        function isComplete()
        {
                if (strlen($this->title) and ($this->author) and ($this->question) and (count($this->answers)) and ($this->getMaximumPoints() > 0))
                {
                        return true;
                }
                        else
                {
                        return false;
                }
        }

        public function saveToDb($original_id = "")
        {
                $this->saveQuestionDataToDb($original_id);
                $this->saveAdditionalQuestionDataToDb();
                $this->saveAnswerSpecificDataToDb();

                $this->ensureNoInvalidObligation($this->getId());
                parent::saveToDb($original_id);
        }

        protected function rebuildThumbnails()
        {
                if ($this->isSingleline && ($this->getThumbSize()))
                {
                        foreach ($this->getAnswers() as $answer)
                        {
                                if (strlen($answer->getImage()))
                                {
                                        $this->generateThumbForFile($this->getImagePath(), $answer->getImage());
                                }
                        }
                }
        }

        public function getThumbPrefix()
        {
                return "thumb.";
        }

        protected function generateThumbForFile($path, $file)
        {
                $filename = $path . $file;
                if (@file_exists($filename))
                {
                        $thumbpath = $path . $this->getThumbPrefix() . $file;
                        $path_info = @pathinfo($filename);
                        $ext = "";
                        switch (strtoupper($path_info['extension']))
                        {
                                case 'PNG':
                                        $ext = 'PNG';
                                        break;
                                case 'GIF':
                                        $ext = 'GIF';
                                        break;
                                default:
                                        $ext = 'JPEG';
                                        break;
                        }
                        ilUtil::convertImage($filename, $thumbpath, $ext, $this->getThumbSize());
                }
        }

        public function loadFromDb($question_id)
        {
                global $ilDB;
                $hasimages = 0;

                $result = $ilDB->queryF("SELECT qpl_questions.*, " . $this->getAdditionalTableName() . ".* FROM qpl_questions LEFT JOIN " . $this->getAdditionalTableName() . " ON " . $this->getAdditionalTableName() . ".question_fi = qpl_questions.question_id WHERE qpl_questions.question_id = %s",
                        array("integer"),
                        array($question_id)
                );
                if ($result->numRows() == 1)
                {
                        $data = $ilDB->fetchAssoc($result);
                        $this->setId($question_id);
                        $this->setObjId($data["obj_fi"]);
                        $this->setTitle($data["title"]);
                        $this->setNrOfTries($data['nr_of_tries']);
                        $this->setComment($data["description"]);
                        $this->setOriginalId($data["original_id"]);
                        $this->setAuthor($data["author"]);
                        $this->setPoints($data["points"]);
                        $this->setOwner($data["owner"]);
                        include_once("./Services/RTE/classes/class.ilRTE.php");
                        $this->setQuestion(ilRTE::_replaceMediaObjectImageSrc($data["question_text"], 1));
                        $shuffle = (is_null($data['shuffle'])) ? true : $data['shuffle'];
                        $this->setShuffle($shuffle);
                        $this->setEstimatedWorkingTime(substr($data["working_time"], 0, 2), substr($data["working_time"], 3, 2), substr($data["working_time"], 6, 2));
                        $this->setThumbSize($data['thumb_size']);
                        $this->isSingleline = ($data['allow_images']) ? false : true;
                        $this->lastChange = $data['tstamp'];
                        $this->feedback_setting = $data['feedback_setting'];
                        
                        try
                        {
                                $this->setAdditionalContentEditingMode($data['add_cont_edit_mode']);
                        }
                        catch(ilTestQuestionPoolException $e)
                        {
                        }
                }

                $result = $ilDB->queryF("SELECT * FROM qpl_a_mc WHERE question_fi = %s ORDER BY aorder ASC",
                        array('integer'),
                        array($question_id)
                );
                include_once "./Modules/TestQuestionPool/classes/class.assAnswerMultipleResponseImage.php";
                if ($result->numRows() > 0)
                {
                        while ($data = $ilDB->fetchAssoc($result))
                        {
                                $imagefilename = $this->getImagePath() . $data["imagefile"];
                                if (!@file_exists($imagefilename))
                                {
                                        $data["imagefile"] = "";
                                }
                                include_once("./Services/RTE/classes/class.ilRTE.php");
                                $data["answertext"] = ilRTE::_replaceMediaObjectImageSrc($data["answertext"], 1);
                                array_push($this->answers, new ASS_AnswerMultipleResponseImage($data["answertext"], $data["points"], $data["aorder"], $data["points_unchecked"], $data["imagefile"]));
                        }
                }

                parent::loadFromDb($question_id);
        }

        public function duplicate($for_test = true, $title = "", $author = "", $owner = "", $testObjId = null)
        {
                if ($this->id <= 0)
                {
                        // The question has not been saved. It cannot be duplicated
                        return;
                }
                // duplicate the question in database
                $this_id = $this->getId();
                $thisObjId = $this->getObjId();
                
                $clone = $this;
                include_once ("./Modules/TestQuestionPool/classes/class.assQuestion.php");
                $original_id = assQuestion::_getOriginalId($this->id);
                $clone->id = -1;
                
                if( (int)$testObjId > 0 )
                {
                        $clone->setObjId($testObjId);
                }
                
                if ($title)
                {
                        $clone->setTitle($title);
                }

                if ($author)
                {
                        $clone->setAuthor($author);
                }
                if ($owner)
                {
                        $clone->setOwner($owner);
                }

                if ($for_test)
                {
                        $clone->saveToDb($original_id);
                }
                else
                {
                        $clone->saveToDb();
                }

                // copy question page content
                $clone->copyPageOfQuestion($this_id);
                // copy XHTML media objects
                $clone->copyXHTMLMediaObjectsOfQuestion($this_id);
                // duplicate the images
                $clone->duplicateImages($this_id, $thisObjId);

                $clone->onDuplicate($thisObjId, $this_id, $clone->getObjId(), $clone->getId());

                return $clone->id;
        }

        public function copyObject($target_questionpool_id, $title = "")
        {
                if ($this->id <= 0)
                {
                        // The question has not been saved. It cannot be duplicated
                        return;
                }
                // duplicate the question in database
                $clone = $this;
                include_once ("./Modules/TestQuestionPool/classes/class.assQuestion.php");
                $original_id = assQuestion::_getOriginalId($this->id);
                $clone->id = -1;
                $source_questionpool_id = $this->getObjId();
                $clone->setObjId($target_questionpool_id);
                if ($title)
                {
                        $clone->setTitle($title);
                }
                $clone->saveToDb();
                // copy question page content
                $clone->copyPageOfQuestion($original_id);
                // copy XHTML media objects
                $clone->copyXHTMLMediaObjectsOfQuestion($original_id);
                // duplicate the image
                $clone->copyImages($original_id, $source_questionpool_id);

                $clone->onCopy($source_questionpool_id, $original_id, $clone->getObjId(), $clone->getId());
                
                return $clone->id;
        }

        public function createNewOriginalFromThisDuplicate($targetParentId, $targetQuestionTitle = "")
        {
                if ($this->id <= 0)
                {
                        // The question has not been saved. It cannot be duplicated
                        return;
                }

                include_once ("./Modules/TestQuestionPool/classes/class.assQuestion.php");

                $sourceQuestionId = $this->id;
                $sourceParentId = $this->getObjId();

                // duplicate the question in database
                $clone = $this;
                $clone->id = -1;

                $clone->setObjId($targetParentId);

                if ($targetQuestionTitle)
                {
                        $clone->setTitle($targetQuestionTitle);
                }

                $clone->saveToDb();
                // copy question page content
                $clone->copyPageOfQuestion($sourceQuestionId);
                // copy XHTML media objects
                $clone->copyXHTMLMediaObjectsOfQuestion($sourceQuestionId);
                // duplicate the image
                $clone->copyImages($sourceQuestionId, $sourceParentId);

                $clone->onCopy($sourceParentId, $sourceQuestionId, $clone->getObjId(), $clone->getId());

                return $clone->id;
        }

        public function getOutputType()
        {
                return $this->output_type;
        }

        public function setOutputType($output_type = OUTPUT_ORDER)
        {
                $this->output_type = $output_type;
        }

        public function addAnswer(
                $answertext = "",
                $points = 0.0,
                $points_unchecked = 0.0,
                $order = 0,
                $answerimage = ""
        )
        {
                include_once "./Modules/TestQuestionPool/classes/class.assAnswerMultipleResponseImage.php";
                if (array_key_exists($order, $this->answers))
                {
                        // insert answer
                        $answer = new ASS_AnswerMultipleResponseImage($answertext, $points, $order, $points_unchecked, $answerimage);
                        $newchoices = array();
                        for ($i = 0; $i < $order; $i++)
                        {
                                array_push($newchoices, $this->answers[$i]);
                        }
                        array_push($newchoices, $answer);
                        for ($i = $order; $i < count($this->answers); $i++)
                        {
                                $changed = $this->answers[$i];
                                $changed->setOrder($i+1);
                                array_push($newchoices, $changed);
                        }
                        $this->answers = $newchoices;
                }
                else
                {
                        // add answer
                        $answer = new ASS_AnswerMultipleResponseImage($answertext, $points, count($this->answers), $points_unchecked, $answerimage);
                        array_push($this->answers, $answer);
                }
        }

        public function getAnswerCount()
        {
                return count($this->answers);
        }

        public function getAnswer($index = 0)
        {
                if ($index < 0) return NULL;
                if (count($this->answers) < 1) return NULL;
                if ($index >= count($this->answers)) return NULL;

                return $this->answers[$index];
        }

        public function deleteAnswer($index = 0)
        {
                if ($index < 0) return;
                if (count($this->answers) < 1) return;
                if ($index >= count($this->answers)) return;
                $answer = $this->answers[$index];
                if (strlen($answer->getImage())) $this->deleteImage($answer->getImage());
                unset($this->answers[$index]);
                $this->answers = array_values($this->answers);
                for ($i = 0; $i < count($this->answers); $i++)
                {
                        if ($this->answers[$i]->getOrder() > $index)
                        {
                                $this->answers[$i]->setOrder($i);
                        }
                }
        }

        public function flushAnswers()
        {
                $this->answers = array();
        }

        public function getMaximumPoints()
        {
                $points = 0;
                $allpoints = 0;
                foreach ($this->answers as $key => $value) 
                {
                        if ($value->getPoints() > $value->getPointsUnchecked())
                        {
                                $allpoints += $value->getPoints();
                        }
                        else
                        {
                                $allpoints += $value->getPointsUnchecked();
                        }
                }
                return $allpoints;
        }

        public function calculateReachedPoints($active_id, $pass = NULL, $returndetails = FALSE)
        {
                if( $returndetails )
                {
                        throw new ilTestException('return details not implemented for '.__METHOD__);
                }
                
                global $ilDB;
                
                $found_values = array();
                if (is_null($pass))
                {
                        $pass = $this->getSolutionMaxPass($active_id);
                }
                $result = $this->getCurrentSolutionResultSet($active_id, $pass);
                while ($data = $ilDB->fetchAssoc($result))
                {
                        if (strcmp($data["value1"], "") != 0)
                        {
                                array_push($found_values, $data["value1"]);
                        }
                }
                
                $points = $this->calculateReachedPointsForSolution($found_values, $active_id);
                
                return $points;
        }
        
        public function saveWorkingData($active_id, $pass = NULL)
        {
                global $ilDB;

                if (is_null($pass))
                {
                        include_once "./Modules/Test/classes/class.ilObjTest.php";
                        $pass = ilObjTest::_getPass($active_id);
                }

                $entered_values = 0;
                
                $this->getProcessLocker()->requestUserSolutionUpdateLock();

                $this->removeCurrentSolution($active_id, $pass);

                $solutionSubmit = $this->getSolutionSubmit();
                
                foreach($solutionSubmit as $value)
                {
                        if (strlen($value))
                        {
                                $this->saveCurrentSolution($active_id, $pass, $value, null);
                                $entered_values++;
                        }
                }

                $this->getProcessLocker()->releaseUserSolutionUpdateLock();
                
                if ($entered_values)
                {
                        include_once ("./Modules/Test/classes/class.ilObjAssessmentFolder.php");
                        if (ilObjAssessmentFolder::_enabledAssessmentLogging())
                        {
                                $this->logAction($this->lng->txtlng("assessment", "log_user_entered_values", ilObjAssessmentFolder::_getLogLanguage()), $active_id, $this->getId());
                        }
                }
                else
                {
                        include_once ("./Modules/Test/classes/class.ilObjAssessmentFolder.php");
                        if (ilObjAssessmentFolder::_enabledAssessmentLogging())
                        {
                                $this->logAction($this->lng->txtlng("assessment", "log_user_not_entered_values", ilObjAssessmentFolder::_getLogLanguage()), $active_id, $this->getId());
                        }
                }

                return true;
        }
        
        public function saveAdditionalQuestionDataToDb()
        {
                global $ilDB;
                $oldthumbsize = 0;
                if ($this->isSingleline && ($this->getThumbSize()))
                {
                        // get old thumbnail size
                        $result = $ilDB->queryF( "SELECT thumb_size FROM " . $this->getAdditionalTableName(
                                                         ) . " WHERE question_fi = %s",
                                                                         array( "integer" ),
                                                                         array( $this->getId() )
                        );
                        if ($result->numRows() == 1)
                        {
                                $data         = $ilDB->fetchAssoc( $result );
                                $oldthumbsize = $data['thumb_size'];
                        }
                }

                if (!$this->isSingleline)
                {
                        ilUtil::delDir( $this->getImagePath() );
                }

                // save additional data
                $ilDB->manipulateF( "DELETE FROM " . $this->getAdditionalTableName() . " WHERE question_fi = %s",
                                                        array( "integer" ),
                                                        array( $this->getId() )
                );

                $ilDB->manipulateF( "INSERT INTO " . $this->getAdditionalTableName() 
                                                        . " (question_fi, shuffle, allow_images, thumb_size) VALUES (%s, %s, %s, %s)",
                                                        array( "integer", "text", "text", "integer" ),
                                                        array(
                                                                $this->getId(),
                                                                $this->getShuffle(),
                                                                ($this->isSingleline) ? "0" : "1",
                                                                (strlen( $this->getThumbSize() ) == 0) ? null : $this->getThumbSize()
                                                        )
                );
        }

        public function saveAnswerSpecificDataToDb()
        {
                global $ilDB;
                $ilDB->manipulateF( "DELETE FROM qpl_a_mc WHERE question_fi = %s",
                                                        array( 'integer' ),
                                                        array( $this->getId() )
                );

                foreach ($this->answers as $key => $value)
                {
                        $answer_obj = $this->answers[$key];
                        $next_id    = $ilDB->nextId( 'qpl_a_mc' );
                        $ilDB->manipulateF( "INSERT INTO qpl_a_mc (answer_id, question_fi, answertext, points, points_unchecked, aorder, imagefile, tstamp) VALUES (%s, %s, %s, %s, %s, %s, %s, %s)",
                                                                array( 'integer', 'integer', 'text', 'float', 'float', 'integer', 'text', 'integer' ),
                                                                array(
                                                                        $next_id,
                                                                        $this->getId(),
                                                                        ilRTE::_replaceMediaObjectImageSrc( $answer_obj->getAnswertext(), 0 ),
                                                                        $answer_obj->getPoints(),
                                                                        $answer_obj->getPointsUnchecked(),
                                                                        $answer_obj->getOrder(),
                                                                        $answer_obj->getImage(),
                                                                        time()
                                                                )
                        );
                }
                $this->rebuildThumbnails();
        }

        protected function reworkWorkingData($active_id, $pass, $obligationsAnswered)
        {
                // nothing to rework!
        }

        function syncWithOriginal()
        {
                if ($this->getOriginalId())
                {
                        $this->syncImages();
                        parent::syncWithOriginal();
                }
        }

        public function getQuestionType()
        {
                return "assMultipleChoice";
        }
        
        public function getAdditionalTableName()
        {
                return "qpl_qst_mc";
        }
        
        public function getAnswerTableName()
        {
                return "qpl_a_mc";
        }
        
        public function setImageFile($image_filename, $image_tempfilename = "")
        {
                $result = 0;
                if (!empty($image_tempfilename))
                {
                        $image_filename = str_replace(" ", "_", $image_filename);
                        $imagepath = $this->getImagePath();
                        if (!file_exists($imagepath))
                        {
                                ilUtil::makeDirParents($imagepath);
                        }
                        if (!ilUtil::moveUploadedFile($image_tempfilename, $image_filename, $imagepath.$image_filename))
                        {
                                $result = 2;
                        }
                        else
                        {
                                include_once "./Services/MediaObjects/classes/class.ilObjMediaObject.php";
                                $mimetype = ilObjMediaObject::getMimeType($imagepath . $image_filename);
                                if (!preg_match("/^image/", $mimetype))
                                {
                                        unlink($imagepath . $image_filename);
                                        $result = 1;
                                }
                                else
                                {
                                        // create thumbnail file
                                        if ($this->isSingleline && ($this->getThumbSize()))
                                        {
                                                $this->generateThumbForFile($imagepath, $image_filename);
                                        }
                                }
                        }
                }
                return $result;
        }
        
        protected function deleteImage($image_filename)
        {
                $imagepath = $this->getImagePath();
                @unlink($imagepath . $image_filename);
                $thumbpath = $imagepath . $this->getThumbPrefix() . $image_filename;
                @unlink($thumbpath);
        }

        function duplicateImages($question_id, $objectId = null)
        {
                global $ilLog;
                $imagepath = $this->getImagePath();
                $imagepath_original = str_replace("/$this->id/images", "/$question_id/images", $imagepath);
                
                if( (int)$objectId > 0 )
                {
                        $imagepath_original = str_replace("/$this->obj_id/", "/$objectId/", $imagepath_original);
                }
                
                foreach ($this->answers as $answer)
                {
                        $filename = $answer->getImage();
                        if (strlen($filename))
                        {
                                if (!file_exists($imagepath))
                                {
                                        ilUtil::makeDirParents($imagepath);
                                }
                                if (!@copy($imagepath_original . $filename, $imagepath . $filename))
                                {
                                        $ilLog->write("image could not be duplicated!!!!", $ilLog->ERROR);
                                        $ilLog->write("object: " . print_r($this, TRUE), $ilLog->ERROR);
                                }
                                if (@file_exists($imagepath_original. $this->getThumbPrefix(). $filename))
                                {
                                        if (!@copy($imagepath_original . $this->getThumbPrefix() . $filename, $imagepath . $this->getThumbPrefix() . $filename))
                                        {
                                                $ilLog->write("image thumbnail could not be duplicated!!!!", $ilLog->ERROR);
                                                $ilLog->write("object: " . print_r($this, TRUE), $ilLog->ERROR);
                                        }
                                }
                        }
                }
        }

        function copyImages($question_id, $source_questionpool)
        {
                global $ilLog;
                $imagepath = $this->getImagePath();
                $imagepath_original = str_replace("/$this->id/images", "/$question_id/images", $imagepath);
                $imagepath_original = str_replace("/$this->obj_id/", "/$source_questionpool/", $imagepath_original);
                foreach ($this->answers as $answer)
                {
                        $filename = $answer->getImage();
                        if (strlen($filename))
                        {
                                if (!file_exists($imagepath))
                                {
                                        ilUtil::makeDirParents($imagepath);
                                }
                                if (!@copy($imagepath_original . $filename, $imagepath . $filename))
                                {
                                        $ilLog->write("image could not be duplicated!!!!", $ilLog->ERROR);
                                        $ilLog->write("object: " . print_r($this, TRUE), $ilLog->ERROR);
                                }
                                if (@file_exists($imagepath_original. $this->getThumbPrefix(). $filename))
                                {
                                        if (!@copy($imagepath_original . $this->getThumbPrefix() . $filename, $imagepath . $this->getThumbPrefix() . $filename))
                                        {
                                                $ilLog->write("image thumbnail could not be duplicated!!!!", $ilLog->ERROR);
                                                $ilLog->write("object: " . print_r($this, TRUE), $ilLog->ERROR);
                                        }
                                }
                        }
                }
        }

        protected function syncImages()
        {
                global $ilLog;
                
                $imagepath = $this->getImagePath();  

                $question_id = $this->getOriginalId(); 
                $originalObjId = parent::lookupParentObjId($this->getOriginalId());
                $imagepath_original = $this->getImagePath($question_id, $originalObjId);

                ilUtil::delDir($imagepath_original);
                foreach ($this->answers as $answer)
                {
                        $filename = $answer->getImage();
                        if (strlen($filename))
                        {
                                if (@file_exists($imagepath . $filename))
                                {
                                        if (!file_exists($imagepath))
                                        {
                                                ilUtil::makeDirParents($imagepath);
                                        }
                                        if (!file_exists($imagepath_original))
                                        {
                                                ilUtil::makeDirParents($imagepath_original);
                                        }
                                        if (!@copy($imagepath . $filename, $imagepath_original . $filename))
                                        {
                                                $ilLog->write("image could not be duplicated!!!!", $ilLog->ERROR);
                                                $ilLog->write("object: " . print_r($this, TRUE), $ilLog->ERROR);
                                        }
                                }
                                if (@file_exists($imagepath . $this->getThumbPrefix() . $filename))
                                {
                                        if (!@copy($imagepath . $this->getThumbPrefix() . $filename, $imagepath_original . $this->getThumbPrefix() . $filename))
                                        {
                                                $ilLog->write("image thumbnail could not be duplicated!!!!", $ilLog->ERROR);
                                                $ilLog->write("object: " . print_r($this, TRUE), $ilLog->ERROR);
                                        }
                                }
                        }
                }
        }

        function getRTETextWithMediaObjects()
        {
                $text = parent::getRTETextWithMediaObjects();
                foreach ($this->answers as $index => $answer)
                {
                        $text .= $this->feedbackOBJ->getSpecificAnswerFeedbackContent($this->getId(), $index);
                        $answer_obj = $this->answers[$index];
                        $text .= $answer_obj->getAnswertext();
                }
                return $text;
        }
        
        function &getAnswers()
        {
                return $this->answers;
        }

        public function setExportDetailsXLS(&$worksheet, $startrow, $active_id, $pass, &$format_title, &$format_bold)
        {
                include_once ("./Services/Excel/classes/class.ilExcelUtils.php");
                $solution = $this->getSolutionValues($active_id, $pass);
                $worksheet->writeString($startrow, 0, ilExcelUtils::_convert_text($this->lng->txt($this->getQuestionType())), $format_title);
                $worksheet->writeString($startrow, 1, ilExcelUtils::_convert_text($this->getTitle()), $format_title);
                $i = 1;
                foreach ($this->getAnswers() as $id => $answer)
                {
                        $worksheet->writeString($startrow + $i, 0, ilExcelUtils::_convert_text($answer->getAnswertext()), $format_bold);
                        $checked = FALSE;
                        foreach ($solution as $solutionvalue)
                        {
                                if ($id == $solutionvalue["value1"])
                                {
                                        $checked = TRUE;
                                }
                        }
                        if ($checked)
                        {
                                $worksheet->write($startrow + $i, 1, 1);
                        }
                        else
                        {
                                $worksheet->write($startrow + $i, 1, 0);
                        }
                        $i++;
                }
                return $startrow + $i + 1;
        }

        public function getThumbSize()
        {
                return $this->thumb_size;
        }
        
        public function setThumbSize($a_size)
        {
                $this->thumb_size = $a_size;
        }

        public function toJSON()
        {
                require_once './Services/RTE/classes/class.ilRTE.php';
                $result = array();
                $result['id'] = (int) $this->getId();
                $result['type'] = (string) $this->getQuestionType();
                $result['title'] = (string) $this->getTitle();
                $result['question'] =  $this->formatSAQuestion($this->getQuestion());
                $result['nr_of_tries'] = (int) $this->getNrOfTries();
                $result['shuffle'] = (bool) $this->getShuffle();
                $result['feedback'] = array(
                        'onenotcorrect' => $this->formatSAQuestion($this->feedbackOBJ->getGenericFeedbackTestPresentation($this->getId(), false)),
                        'allcorrect' => $this->formatSAQuestion($this->feedbackOBJ->getGenericFeedbackTestPresentation($this->getId(), true))
                );

                $answers = array();
                $has_image = false;
                foreach ($this->getAnswers() as $key => $answer_obj)
                {
                        if((string) $answer_obj->getImage())
                        {
                                $has_image = true;
                        }
                        array_push($answers, array(
                                "answertext" => (string) $this->formatSAQuestion($answer_obj->getAnswertext()),
                                "points_checked" => (float) $answer_obj->getPointsChecked(),
                                "points_unchecked" => (float) $answer_obj->getPointsUnchecked(),
                                "order" => (int) $answer_obj->getOrder(),
                                "image" => (string) $answer_obj->getImage(),
                                "feedback" => $this->formatSAQuestion(
                                                $this->feedbackOBJ->getSpecificAnswerFeedbackExportPresentation($this->getId(), $key)
                                )
                        ));
                }
                $result['answers'] = $answers;

                if($has_image)
                {
                        $result['path'] = $this->getImagePathWeb();
                        $result['thumb'] = $this->getThumbSize();
                }

                $mobs = ilObjMediaObject::_getMobsOfObject("qpl:html", $this->getId());
                $result['mobs'] = $mobs;
                
                return json_encode($result);
        }

        public function removeAnswerImage($index)
        {
                $answer = $this->answers[$index];
                if (is_object($answer))
                {
                        $this->deleteImage($answer->getImage());
                        $answer->setImage('');
                }
        }

        function getMultilineAnswerSetting()
        {
                global $ilUser;

                $multilineAnswerSetting = $ilUser->getPref("tst_multiline_answers");
                if ($multilineAnswerSetting != 1)
                {
                        $multilineAnswerSetting = 0;
                }
                return $multilineAnswerSetting;
        }
        
        function setMultilineAnswerSetting($a_setting = 0)
        {
                global $ilUser;
                $ilUser->writePref("tst_multiline_answers", $a_setting);
        }
        
        function setSpecificFeedbackSetting($a_feedback_setting)
        {
                $this->feedback_setting = $a_feedback_setting;
        }
        
        function getSpecificFeedbackSetting()
        {
                if ($this->feedback_setting)
                {
                        return $this->feedback_setting;
                }
                else
                {
                        return 1;
                }
        }
        
        public function isAnswered($active_id, $pass)
        {
                $numExistingSolutionRecords = assQuestion::getNumExistingSolutionRecords($active_id, $pass, $this->getId());

                return $numExistingSolutionRecords > 0;
        }
        
        public static function isObligationPossible($questionId)
        {
                global $ilDB;
                
                $query = "
                        SELECT SUM(points) points_for_checked_answers
                        FROM qpl_a_mc
                        WHERE question_fi = %s AND points > 0
                ";
                
                $res = $ilDB->queryF($query, array('integer'), array($questionId));
                
                $row = $ilDB->fetchAssoc($res);
                
                return $row['points_for_checked_answers'] > 0;
        }
        
        public function ensureNoInvalidObligation($questionId)
        {
                global $ilDB;
                
                $query = "
                        SELECT          SUM(qpl_a_mc.points) points_for_checked_answers,
                                                test_question_id
                        
                        FROM            tst_test_question
                        
                        INNER JOIN      qpl_a_mc
                        ON                      qpl_a_mc.question_fi = tst_test_question.question_fi
                        
                        WHERE           tst_test_question.question_fi = %s
                        AND                     tst_test_question.obligatory = 1
                        
                        GROUP BY        test_question_id
                ";
                
                $res = $ilDB->queryF($query, array('integer'), array($questionId));
                
                $updateTestQuestionIds = array();
                
                while( $row = $ilDB->fetchAssoc($res) )
                {
                        if( $row['points_for_checked_answers'] <= 0 )
                        {
                                $updateTestQuestionIds[] = $row['test_question_id'];
                        }
                }
                
                if( count($updateTestQuestionIds) )
                {
                        $test_question_id__IN__updateTestQuestionIds = $ilDB->in(
                                        'test_question_id', $updateTestQuestionIds, false, 'integer'
                        );
                        
                        $query = "
                                UPDATE tst_test_question
                                SET obligatory = 0
                                WHERE $test_question_id__IN__updateTestQuestionIds
                        ";
                        
                        $ilDB->manipulate($query);
                }
        }

        protected function getSolutionSubmit()
        {
                $solutionSubmit = array();
                foreach($_POST as $key => $value)
                {
                        if(preg_match("/^multiple_choice_result_(\d+)/", $key))
                        {
                                if(strlen($value))
                                {
                                        $solutionSubmit[] = $value;
                                }
                        }
                }
                return $solutionSubmit;
        }

        protected function calculateReachedPointsForSolution($found_values, $active_id = 0)
        {
                $points = 0;
                foreach($this->answers as $key => $answer)
                {
                        if(in_array($key, $found_values))
                        {
                                $points += $answer->getPoints();
                        } else
                        {
                                $points += $answer->getPointsUnchecked();
                        }
                }
                if($active_id)
                {
                        include_once "./Modules/Test/classes/class.ilObjTest.php";
                        $mc_scoring = ilObjTest::_getMCScoring($active_id);
                        if(($mc_scoring == 0) && (count($found_values) == 0))
                        {
                                $points = 0;
                        }
                }
                return $points;
        }

        public function getOperators($expression)
        {
                require_once "./Modules/TestQuestionPool/classes/class.ilOperatorsExpressionMapping.php";
                return ilOperatorsExpressionMapping::getOperatorsByExpression($expression);
        }

        public function getExpressionTypes()
        {
                return array(
                        iQuestionCondition::PercentageResultExpression,
                        iQuestionCondition::NumberOfResultExpression,
                        iQuestionCondition::ExclusiveResultExpression,
                        iQuestionCondition::EmptyAnswerExpression,
                );
        }

        public function getUserQuestionResult($active_id, $pass)
        {
                global $ilDB;
                $result = new ilUserQuestionResult($this, $active_id, $pass);

                $data = $ilDB->queryF(
                        "SELECT value1+1 as value1 FROM tst_solutions WHERE active_fi = %s AND pass = %s AND question_fi = %s AND step = (
                                SELECT MAX(step) FROM tst_solutions WHERE active_fi = %s AND pass = %s AND question_fi = %s
                        )",
                        array("integer", "integer", "integer","integer", "integer", "integer"),
                        array($active_id, $pass, $this->getId(), $active_id, $pass, $this->getId())
                );

                while($row = $ilDB->fetchAssoc($data))
                {
                        $result->addKeyValue($row["value1"], $row["value1"]);
                }

                $points = $this->calculateReachedPoints($active_id, $pass);
                $max_points = $this->getMaximumPoints();

                $result->setReachedPercentage(($points/$max_points) * 100);

                return $result;
        }

        public function getAvailableAnswerOptions($index = null)
        {
                if($index !== null)
                {
                        return $this->getAnswer($index);
                }
                else
                {
                        return $this->getAnswers();
                }
        }
}