Modules/TestQuestionPool/classes/class.assMultipleChoice.php

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<?php
 /*
   +----------------------------------------------------------------------------+
   | ILIAS open source                                                          |
   +----------------------------------------------------------------------------+
   | Copyright (c) 1998-2001 ILIAS open source, University of Cologne           |
   |                                                                            |
   | This program is free software; you can redistribute it and/or              |
   | modify it under the terms of the GNU General Public License                |
   | as published by the Free Software Foundation; either version 2             |
   | of the License, or (at your option) any later version.                     |
   |                                                                            |
   | This program is distributed in the hope that it will be useful,            |
   | but WITHOUT ANY WARRANTY; without even the implied warranty of             |
   | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              |
   | GNU General Public License for more details.                               |
   |                                                                            |
   | You should have received a copy of the GNU General Public License          |
   | along with this program; if not, write to the Free Software                |
   | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
   +----------------------------------------------------------------------------+
*/
include_once "./Modules/TestQuestionPool/classes/class.assQuestion.php";
include_once "./Modules/Test/classes/inc.AssessmentConstants.php";

class assMultipleChoice extends assQuestion
{
        var $answers;

        var $output_type;

        function assMultipleChoice(
                $title = "",
                $comment = "",
                $author = "",
                $owner = -1,
                $question = "",
                $output_type = OUTPUT_ORDER
          )
        {
                $this->assQuestion($title, $comment, $author, $owner, $question);
                $this->output_type = $output_type;
                $this->answers = array();
        }

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

        function saveToDb($original_id = "")
        {
                global $ilDB;

                $complete = 0;
                if ($this->isComplete())
                {
                        $complete = 1;
                }

                $estw_time = $this->getEstimatedWorkingTime();
                $estw_time = sprintf("%02d:%02d:%02d", $estw_time['h'], $estw_time['m'], $estw_time['s']);

                if ($original_id)
                {
                        $original_id = $ilDB->quote($original_id);
                }
                else
                {
                        $original_id = "NULL";
                }
                
                include_once("./Services/RTE/classes/class.ilRTE.php");

                if ($this->id == -1)
                {
                        // Neuen Datensatz schreiben
                        $now = getdate();
                        $question_type = $this->getQuestionTypeID();
                        $created = sprintf("%04d%02d%02d%02d%02d%02d", $now['year'], $now['mon'], $now['mday'], $now['hours'], $now['minutes'], $now['seconds']);
                        $query = sprintf("INSERT INTO qpl_questions (question_id, question_type_fi, obj_fi, title, comment, author, owner, question_text, points, working_time, complete, created, original_id, TIMESTAMP) VALUES (NULL, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, NULL)",
                                $ilDB->quote($question_type),
                                $ilDB->quote($this->obj_id),
                                $ilDB->quote($this->title),
                                $ilDB->quote($this->comment),
                                $ilDB->quote($this->author),
                                $ilDB->quote($this->owner),
                                $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($this->question, 0)),
                                $ilDB->quote($this->getMaximumPoints() . ""),
                                $ilDB->quote($estw_time),
                                $ilDB->quote("$complete"),
                                $ilDB->quote($created),
                                $original_id
                        );
                        $result = $ilDB->query($query);
                        
                        if ($result == DB_OK)
                        {
                                $this->id = $ilDB->getLastInsertId();
                                $query = sprintf("INSERT INTO qpl_question_multiplechoice (question_fi, shuffle) VALUES (%s, %s)",
                                        $ilDB->quote($this->id . ""),
                                        $ilDB->quote("$this->shuffle")
                                );
                                $ilDB->query($query);

                                // create page object of question
                                $this->createPageObject();

                                // Falls die Frage in einen Test eingefügt werden soll, auch diese Verbindung erstellen
                                if ($this->getTestId() > 0)
                                {
                                $this->insertIntoTest($this->getTestId());
                                }
                        }
                }
                else
                {
                        // Vorhandenen Datensatz aktualisieren
                        $query = sprintf("UPDATE qpl_questions SET obj_fi = %s, title = %s, comment = %s, author = %s, question_text = %s, points = %s, working_time=%s, complete = %s WHERE question_id = %s",
                                $ilDB->quote($this->obj_id. ""),
                                $ilDB->quote($this->title),
                                $ilDB->quote($this->comment),
                                $ilDB->quote($this->author),
                                $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($this->question, 0)),
                                $ilDB->quote($this->getMaximumPoints() . ""),
                                $ilDB->quote($estw_time),
                                $ilDB->quote("$complete"),
                                $ilDB->quote($this->id)
                        );
                        $result = $ilDB->query($query);
                        $query = sprintf("UPDATE qpl_question_multiplechoice SET shuffle = %s WHERE question_fi = %s",
                                $ilDB->quote("$this->shuffle"),
                                $ilDB->quote($this->id . "")
                        );
                        $result = $ilDB->query($query);
                }
                
                if ($result == DB_OK)
                {
                        // Antworten schreiben
                        // alte Antworten löschen
                        $query = sprintf("DELETE FROM qpl_answer_multiplechoice WHERE question_fi = %s",
                                $ilDB->quote($this->id)
                        );
                        $result = $ilDB->query($query);

                        // Anworten wegschreiben
                        foreach ($this->answers as $key => $value)
                        {
                                $answer_obj = $this->answers[$key];

                                $query = sprintf("INSERT INTO qpl_answer_multiplechoice (answer_id, question_fi, answertext, points, points_unchecked, aorder, imagefile) VALUES (NULL, %s, %s, %s, %s, %s, %s)",
                                        $ilDB->quote($this->id),
                                        $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($answer_obj->getAnswertext(), 0)),
                                        $ilDB->quote($answer_obj->getPoints() . ""),
                                        $ilDB->quote($answer_obj->getPointsUnchecked() . ""),
                                        $ilDB->quote($answer_obj->getOrder() . ""),
                                        $ilDB->quote($answer_obj->getImage() . "")
                                );
                                $answer_result = $ilDB->query($query);
                        }
                }

                parent::saveToDb($original_id);
        }

        function loadFromDb($question_id)
        {
                global $ilDB;

                $hasimages = 0;
    $query = sprintf("SELECT qpl_questions.*, qpl_question_multiplechoice.* FROM qpl_questions, qpl_question_multiplechoice WHERE question_id = %s AND qpl_questions.question_id = qpl_question_multiplechoice.question_fi",
                $ilDB->quote($question_id));
                $result = $ilDB->query($query);
                if (strcmp(strtolower(get_class($result)), db_result) == 0)
                {
                        if ($result->numRows() == 1)
                        {
                                $data = $result->fetchRow(DB_FETCHMODE_OBJECT);
                                $this->id = $question_id;
                                $this->title = $data->title;
                                $this->comment = $data->comment;
                                $this->solution_hint = $data->solution_hint;
                                $this->original_id = $data->original_id;
                                $this->obj_id = $data->obj_fi;
                                $this->author = $data->author;
                                $this->owner = $data->owner;
                                $this->points = $data->points;
                                include_once("./Services/RTE/classes/class.ilRTE.php");
                                $this->question = ilRTE::_replaceMediaObjectImageSrc($data->question_text, 1);
                                $this->setShuffle($data->shuffle);
                                $this->setEstimatedWorkingTime(substr($data->working_time, 0, 2), substr($data->working_time, 3, 2), substr($data->working_time, 6, 2));
                        }

                        $query = sprintf("SELECT * FROM qpl_answer_multiplechoice WHERE question_fi = %s ORDER BY aorder ASC",
                                $ilDB->quote($question_id));

                        $result = $ilDB->query($query);

                        include_once "./Modules/TestQuestionPool/classes/class.assAnswerMultipleResponseImage.php";
                        if (strcmp(strtolower(get_class($result)), db_result) == 0)
                        {
                                while ($data = $result->fetchRow(DB_FETCHMODE_OBJECT))
                                {
                                        $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);
                                        if (strlen($data->imagefile)) $hasimages = 1;
                                        array_push($this->answers, new ASS_AnswerMultipleResponseImage($data->answertext, $data->points, $data->aorder, $data->points_unchecked, $data->imagefile));
                                }
                        }
                }
                $this->setGraphicalAnswerSetting($hasimages);
                parent::loadFromDb($question_id);
        }

        /*function addAnswer($answertext, $points, $answerorder, $correctness)
        {
                include_once "./Modules/TestQuestionPool/classes/class.assAnswerBinaryState.php";
                array_push($this->answers, new ASS_AnswerBinaryState($answertext, $points, $answerorder, $correctness));
        }*/
        
        function duplicate($for_test = true, $title = "", $author = "", $owner = "")
        {
                if ($this->id <= 0)
                {
                        // The question has not been saved. It cannot be duplicated
                        return;
                }
                // duplicate the question in database
                $this_id = $this->getId();
                $clone = $this;
                include_once ("./Modules/TestQuestionPool/classes/class.assQuestion.php");
                $original_id = assQuestion::_getOriginalId($this->id);
                $clone->id = -1;
                if ($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);
                // duplicate the generic feedback
                $clone->duplicateFeedbackGeneric($this_id);
                // duplicate the answer specific feedback
                $clone->duplicateFeedbackAnswer($this_id);

                return $clone->id;
        }

        function copyObject($target_questionpool, $title = "")
        {
                if ($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 = $this->getObjId();
                $clone->setObjId($target_questionpool);
                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);
                // duplicate the generic feedback
                $clone->duplicateFeedbackGeneric($original_id);
                // duplicate the answer specific feedback
                $clone->duplicateFeedbackAnswer($original_id);

                return $clone->id;
        }

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

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

        function addAnswer(
                $answertext = "",
                $points = 0.0,
                $points_unchecked = 0.0,
                $order = 0,
                $answerimage = ""
        )
        {
                $found = -1;
                foreach ($this->answers as $key => $value)
                {
                        if ($value->getOrder() == $order)
                        {
                                $found = $order;
                        }
                }
                include_once "./Modules/TestQuestionPool/classes/class.assAnswerMultipleResponseImage.php";
                if ($found >= 0)
                {
                        // Antwort einfügen
                        $answer = new ASS_AnswerMultipleResponseImage($answertext, $points, $found, $points_unchecked, $answerimage);
                        array_push($this->answers, $answer);
                        for ($i = $found + 1; $i < count($this->answers); $i++)
                        {
                                $this->answers[$i] = $this->answers[$i-1];
                        }
                        $this->answers[$found] = $answer;
                }
                else
                {
                        // Anwort anhängen
                        $answer = new ASS_AnswerMultipleResponseImage($answertext, $points, count($this->answers), $points_unchecked, $answerimage);
                        array_push($this->answers, $answer);
                }
        }

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

        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];
        }

        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);
                        }
                }
        }

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

        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;
        }

        function calculateReachedPoints($active_id, $pass = NULL)
        {
                global $ilDB;
                
                $found_values = array();
                if (is_null($pass))
                {
                        $pass = $this->getSolutionMaxPass($active_id);
                }
                $query = sprintf("SELECT * FROM tst_solutions WHERE active_fi = %s AND question_fi = %s AND pass = %s",
                        $ilDB->quote($active_id . ""),
                        $ilDB->quote($this->getId() . ""),
                        $ilDB->quote($pass . "")
                );
                $result = $ilDB->query($query);
                while ($data = $result->fetchRow(DB_FETCHMODE_OBJECT))
                {
                        if (strcmp($data->value1, "") != 0)
                        {
                                array_push($found_values, $data->value1);
                        }
                }
                $points = 0;
                foreach ($this->answers as $key => $answer)
                {
                        if (in_array($key, $found_values))
                        {
                                $points += $answer->getPoints();
                        }
                        else
                        {
                                $points += $answer->getPointsUnchecked();
                        }
                }
                include_once "./Modules/Test/classes/class.ilObjTest.php";
                $mc_scoring = ilObjTest::_getMCScoring($active_id);
                if (($mc_scoring == 0) && (count($found_values) == 0))
                {
                        $points = 0;
                }
                $points = parent::calculateReachedPoints($active_id, $pass = NULL, $points);
                return $points;
        }
        
        function saveWorkingData($active_id, $pass = NULL)
        {
                global $ilDB;
                global $ilUser;

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

                $entered_values = 0;
                $query = sprintf("DELETE FROM tst_solutions WHERE active_fi = %s AND question_fi = %s AND pass = %s",
                        $ilDB->quote($active_id . ""),
                        $ilDB->quote($this->getId() . ""),
                        $ilDB->quote($pass . "")
                );
                $result = $ilDB->query($query);
                foreach ($_POST as $key => $value)
                {
                        if (preg_match("/^multiple_choice_result_(\d+)/", $key, $matches))
                        {
                                if (strlen($value))
                                {
                                        $query = sprintf("INSERT INTO tst_solutions (solution_id, active_fi, question_fi, value1, value2, pass, TIMESTAMP) VALUES (NULL, %s, %s, %s, NULL, %s, NULL)",
                                                $ilDB->quote($active_id),
                                                $ilDB->quote($this->getId()),
                                                $ilDB->quote($value),
                                                $ilDB->quote($pass . "")
                                        );
                                        $result = $ilDB->query($query);
                                        $entered_values++;
                                }
                        }
                }
                if ($entered_values)
                {
                        include_once ("./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 ("./classes/class.ilObjAssessmentFolder.php");
                        if (ilObjAssessmentFolder::_enabledAssessmentLogging())
                        {
                                $this->logAction($this->lng->txtlng("assessment", "log_user_not_entered_values", ilObjAssessmentFolder::_getLogLanguage()), $active_id, $this->getId());
                        }
                }
    parent::saveWorkingData($active_id, $pass);
                return true;
        }

        function syncFeedbackSingleAnswers()
        {
                global $ilDB;

                $feedback = "";

                // delete generic feedback of the original
                $deletequery = sprintf("DELETE FROM qpl_feedback_multiplechoice WHERE question_fi = %s",
                        $ilDB->quote($this->original_id . "")
                );
                $result = $ilDB->query($deletequery);
                        
                // get generic feedback of the actual question
                $query = sprintf("SELECT * FROM qpl_feedback_multiplechoice WHERE question_fi = %s",
                        $ilDB->quote($this->getId() . "")
                );
                $result = $ilDB->query($query);

                // save generic feedback to the original
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                        {
                                $duplicatequery = sprintf("INSERT INTO qpl_feedback_multiplechoice VALUES (NULL, %s, %s, %s, NULL)",
                                        $ilDB->quote($this->original_id . ""),
                                        $ilDB->quote($row["answer"] . ""),
                                        $ilDB->quote($row["feedback"] . "")
                                );
                                $duplicateresult = $ilDB->query($duplicatequery);
                        }
                }
        }

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

        function getQuestionType()
        {
                return "assMultipleChoice";
        }
        
        function getAdditionalTableName()
        {
                return "qpl_question_multiplechoice";
        }
        
        function getAnswerTableName()
        {
                return "qpl_answer_multiplechoice";
        }
        
        function getGraphicalAnswerSetting()
        {
                global $ilUser;

                $graphicalAnswerSetting = $ilUser->getPref("graphicalAnswerSetting");
                if ($graphicalAnswerSetting != 1)
                {
                        $graphicalAnswerSetting = 0;
                }
                return $graphicalAnswerSetting;
        }
        
        function setGraphicalAnswerSetting($a_setting = 0)
        {
                global $ilUser;
                $ilUser->writePref("graphicalAnswerSetting", $a_setting);
        }

        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($imagepath);
                        }
                        //if (!move_uploaded_file($image_tempfilename, $imagepath . $image_filename))
                        if (!ilUtil::moveUploadedFile($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
                                        $thumbpath = $imagepath . $image_filename . "." . "thumb.jpg";
                                        ilUtil::convertImage($imagepath.$image_filename, $thumbpath, "JPEG", 100);
                                }
                        }
                }
                return $result;
        }
        
        function deleteImage($image_filename)
        {
                $imagepath = $this->getImagePath();
                unlink($imagepath . $image_filename);
                $thumbpath = $imagepath . $image_filename . "." . "thumb.jpg";
                unlink($thumbpath);
        }

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

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

        function saveFeedbackSingleAnswer($answer_index, $feedback)
        {
                global $ilDB;
                
                $query = sprintf("DELETE FROM qpl_feedback_multiplechoice WHERE question_fi = %s AND answer = %s",
                        $ilDB->quote($this->getId() . ""),
                        $ilDB->quote($answer_index . "")
                );
                $result = $ilDB->query($query);
                if (strlen($feedback))
                {
                        include_once("./Services/RTE/classes/class.ilRTE.php");
                        $query = sprintf("INSERT INTO qpl_feedback_multiplechoice VALUES (NULL, %s, %s, %s, NULL)",
                                $ilDB->quote($this->getId() . ""),
                                $ilDB->quote($answer_index . ""),
                                $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($feedback, 0))
                        );
                        $result = $ilDB->query($query);
                }
        }

        function getFeedbackSingleAnswer($answer_index)
        {
                global $ilDB;
                
                $feedback = "";
                $query = sprintf("SELECT * FROM qpl_feedback_multiplechoice WHERE question_fi = %s AND answer = %s",
                        $ilDB->quote($this->getId() . ""),
                        $ilDB->quote($answer_index . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        include_once("./Services/RTE/classes/class.ilRTE.php");
                        $feedback = ilRTE::_replaceMediaObjectImageSrc($row["feedback"], 1);
                }
                return $feedback;
        }

        function duplicateFeedbackAnswer($original_id)
        {
                global $ilDB;
                
                $feedback = "";
                $query = sprintf("SELECT * FROM qpl_feedback_multiplechoice WHERE question_fi = %s",
                        $ilDB->quote($original_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                        {
                                $duplicatequery = sprintf("INSERT INTO qpl_feedback_multiplechoice VALUES (NULL, %s, %s, %s, NULL)",
                                        $ilDB->quote($this->getId() . ""),
                                        $ilDB->quote($row["answer"] . ""),
                                        $ilDB->quote($row["feedback"] . "")
                                );
                                $duplicateresult = $ilDB->query($duplicatequery);
                        }
                }
        }

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

?>