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';
require_once 'Modules/TestQuestionPool/interfaces/interface.ilAssSpecificFeedbackOptionLabelProvider.php';

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

    public $output_type;

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

    protected $thumb_size;
    
    protected $selectionLimit;
    
    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;
        $this->selectionLimit = null;
        $this->feedback_setting = 0;
    }
    
    public function getSelectionLimit()
    {
        return $this->selectionLimit;
    }
    
    public function setSelectionLimit($selectionLimit)
    {
        $this->selectionLimit = $selectionLimit;
    }

    public 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 $DIC;
        $ilDB = $DIC['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->setSelectionLimit((int) $data['selection_limit'] > 0 ? (int) $data['selection_limit'] : null);
            $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, $authorizedSolution = true, $returndetails = false)
    {
        if ($returndetails) {
            throw new ilTestException('return details not implemented for ' . __METHOD__);
        }
        
        global $DIC;
        $ilDB = $DIC['ilDB'];
        
        $found_values = array();
        if (is_null($pass)) {
            $pass = $this->getSolutionMaxPass($active_id);
        }
        $result = $this->getCurrentSolutionResultSet($active_id, $pass, $authorizedSolution);
        while ($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 validateSolutionSubmit()
    {
        $submit = $this->getSolutionSubmit();
        
        if ($this->getSelectionLimit()) {
            if (count($submit) > $this->getSelectionLimit()) {
                $failureMsg = sprintf(
                    $this->lng->txt('ass_mc_sel_lim_exhausted_hint'),
                    $this->getSelectionLimit(),
                    $this->getAnswerCount()
                );
                
                ilUtil::sendFailure($failureMsg, true);
                return false;
            }
        }
        
        return true;
    }
    
    protected function isForcedEmptySolution($solutionSubmit)
    {
        if (!count($solutionSubmit) && !empty($_POST['tst_force_form_diff_input'])) {
            return true;
        }
        
        return false;
    }
    
    public function saveWorkingData($active_id, $pass = null, $authorized = true)
    {
        global $DIC;
        $ilDB = $DIC['ilDB'];

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

        $entered_values = 0;

        $this->getProcessLocker()->executeUserSolutionUpdateLockOperation(function () use (&$entered_values, $active_id, $pass, $authorized) {
            $this->removeCurrentSolution($active_id, $pass, $authorized);

            $solutionSubmit = $this->getSolutionSubmit();

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

            // fau: testNav - write a dummy entry for the evil mc questions with "None of the above" checked
            if ($this->isForcedEmptySolution($solutionSubmit)) {
                $this->saveCurrentSolution($active_id, $pass, 'mc_none_above', null, $authorized);
                $entered_values++;
            }
            // fau.
        });

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

        return true;
    }
    
    public function saveAdditionalQuestionDataToDb()
    {
        global $DIC;
        $ilDB = $DIC['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->replace(
            $this->getAdditionalTableName(),
            array(
                'shuffle' => array('text', $this->getShuffle()),
                'allow_images' => array('text', $this->isSingleline ? 0 : 1),
                'thumb_size' => array('integer', strlen($this->getThumbSize()) ? $this->getThumbSize() : null),
                'selection_limit' => array('integer', $this->getSelectionLimit()),
                'feedback_setting' => array('integer', $this->getSpecificFeedbackSetting())
            ),
            array(
                'question_fi' => array('integer', $this->getId())
            )
        );
    }

    public function saveAnswerSpecificDataToDb()
    {
        global $DIC;
        $ilDB = $DIC['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();
    }

    public 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);
    }

    public function duplicateImages($question_id, $objectId = null)
    {
        global $DIC;
        $ilLog = $DIC['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 (file_exists($imagepath_original . $filename)) {
                    if (!copy($imagepath_original . $filename, $imagepath . $filename)) {
                        $ilLog->warning(sprintf(
                            "Could not clone source image '%s' to '%s' (srcQuestionId: %s|tgtQuestionId: %s|srcParentObjId: %s|tgtParentObjId: %s)",
                            $imagepath_original . $filename,
                            $imagepath . $filename,
                            $question_id,
                            $this->id,
                            $objectId,
                            $this->obj_id
                        ));
                    }
                }

                if (file_exists($imagepath_original . $this->getThumbPrefix() . $filename)) {
                    if (!copy($imagepath_original . $this->getThumbPrefix() . $filename, $imagepath . $this->getThumbPrefix() . $filename)) {
                        $ilLog->warning(sprintf(
                            "Could not clone thumbnail source image '%s' to '%s' (srcQuestionId: %s|tgtQuestionId: %s|srcParentObjId: %s|tgtParentObjId: %s)",
                            $imagepath_original . $this->getThumbPrefix() . $filename,
                            $imagepath . $this->getThumbPrefix() . $filename,
                            $question_id,
                            $this->id,
                            $objectId,
                            $this->obj_id
                        ));
                    }
                }
            }
        }
    }

    public function copyImages($question_id, $source_questionpool)
    {
        global $DIC;
        $ilLog = $DIC['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 $DIC;
        $ilLog = $DIC['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);
                    }
                }
            }
        }
    }

    public function getRTETextWithMediaObjects()
    {
        $text = parent::getRTETextWithMediaObjects();
        foreach ($this->answers as $index => $answer) {
            $text .= $this->feedbackOBJ->getSpecificAnswerFeedbackContent($this->getId(), 0, $index);
            $answer_obj = $this->answers[$index];
            $text .= $answer_obj->getAnswertext();
        }
        return $text;
    }
    
    public function &getAnswers()
    {
        return $this->answers;
    }

    public function setExportDetailsXLS($worksheet, $startrow, $active_id, $pass)
    {
        parent::setExportDetailsXLS($worksheet, $startrow, $active_id, $pass);

        $solution = $this->getSolutionValues($active_id, $pass);

        $i = 1;
        foreach ($this->getAnswers() as $id => $answer) {
            $worksheet->setCell($startrow + $i, 0, $answer->getAnswertext());
            $worksheet->setBold($worksheet->getColumnCoord(0) . ($startrow + $i));
            $checked = false;
            foreach ($solution as $solutionvalue) {
                if ($id == $solutionvalue["value1"]) {
                    $checked = true;
                }
            }
            if ($checked) {
                $worksheet->setCell($startrow + $i, 1, 1);
            } else {
                $worksheet->setCell($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;
    }
    
    protected function lmMigrateQuestionTypeSpecificContent(ilAssSelfAssessmentMigrator $migrator)
    {
        foreach ($this->getAnswers() as $answer) {
            /* @var ASS_AnswerBinaryStateImage $answer */
            $answer->setAnswertext($migrator->migrateToLmContent($answer->getAnswertext()));
        }
    }

    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['selection_limit'] = (int) $this->getSelectionLimit();
        $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(), 0, $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('');
        }
    }

    public function getMultilineAnswerSetting()
    {
        global $DIC;
        $ilUser = $DIC['ilUser'];

        $multilineAnswerSetting = $ilUser->getPref("tst_multiline_answers");
        if ($multilineAnswerSetting != 1) {
            $multilineAnswerSetting = 0;
        }
        return $multilineAnswerSetting;
    }
    
    public function setMultilineAnswerSetting($a_setting = 0)
    {
        global $DIC;
        $ilUser = $DIC['ilUser'];
        $ilUser->writePref("tst_multiline_answers", $a_setting);
    }
    
    public function setSpecificFeedbackSetting($a_feedback_setting)
    {
        $this->feedback_setting = $a_feedback_setting;
    }
    
    public function getSpecificFeedbackSetting()
    {
        if ($this->feedback_setting) {
            return $this->feedback_setting;
        } else {
            return 1;
        }
    }

    public function getSpecificFeedbackAllCorrectOptionLabel()
    {
        return 'feedback_correct_sc_mc';
    }
    
    public function isAnswered($active_id, $pass = null)
    {
        $numExistingSolutionRecords = assQuestion::getNumExistingSolutionRecords($active_id, $pass, $this->getId());

        return $numExistingSolutionRecords > 0;
    }
    
    public static function isObligationPossible($questionId)
    {
        global $DIC;
        $ilDB = $DIC['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 $DIC;
        $ilDB = $DIC['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 $DIC;
        $ilDB = $DIC['ilDB'];
        $result = new ilUserQuestionResult($this, $active_id, $pass);

        $maxStep = $this->lookupMaxStep($active_id, $pass);

        if ($maxStep !== null) {
            $data = $ilDB->queryF(
                "SELECT value1+1 as value1 FROM tst_solutions WHERE active_fi = %s AND pass = %s AND question_fi = %s AND step = %s",
                array("integer", "integer", "integer","integer"),
                array($active_id, $pass, $this->getId(), $maxStep)
            );
        } else {
            $data = $ilDB->queryF(
                "SELECT value1+1 as value1 FROM tst_solutions WHERE active_fi = %s AND pass = %s AND question_fi = %s",
                array("integer", "integer", "integer"),
                array($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();
        }
    }
    
    protected function buildTestPresentationConfig()
    {
        $config = parent::buildTestPresentationConfig();
        $config->setUseUnchangedAnswerLabel($this->lng->txt('tst_mc_label_none_above'));
        return $config;
    }
}