assessment/classes/class.assQuestion.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 "./assessment/classes/inc.AssessmentConstants.php";

class assQuestion
{
        var $id;

        var $title;

        var $comment;

        var $owner;

        var $author;

        var $points;

        var $est_working_time;

        var $shuffle;

        var $test_id;

        var $obj_id;

        var $ilias;

        var $tpl;

        var $lng;

        var $domxml;

        var $outputType;

        var $suggested_solutions;
        function assQuestion(
                $title = "",
                $comment = "",
                $author = "",
                $owner = -1
        )
        {
                global $ilias;
                global $lng;
                global $tpl;

                $this->ilias =& $ilias;
                $this->lng =& $lng;
                $this->tpl =& $tpl;

                $this->title = $title;
                $this->comment = $comment;
                $this->author = $author;
                if (!$this->author)
                {
                        $this->author = $this->ilias->account->fullname;
                }
                $this->owner = $owner;
                if ($this->owner == -1)
                {
                        $this->owner = $this->ilias->account->id;
                }
                $this->id = -1;
                $this->test_id = -1;
                $this->suggested_solutions = array();
                $this->shuffle = 1;
                $this->setEstimatedWorkingTime(0,1,0);
                $this->outputType = OUTPUT_HTML;
                register_shutdown_function(array(&$this, '_assQuestion'));
        }

        function _assQuestion()
        {
                if (!empty($this->domxml))
                {
                        $this->domxml->free();
                }
        }

        function to_xml()
        {
                // to be implemented in the successor classes of assQuestion
        }

        function isComplete()
        {
                return false;
        }

        function questionTitleExists($questionpool_id, $title)
        {
                global $ilDB;
                
                $query = sprintf("SELECT * FROM qpl_questions WHERE obj_fi = %s AND title = %s",
                        $ilDB->quote($questionpool_id . ""),
                        $ilDB->quote($title)
                        );
                $result = $ilDB->query($query);
                if (strcmp(strtolower(get_class($result)), db_result) == 0)
                {
                        if ($result->numRows() == 1)
                        {
                                return TRUE;
                        }
                }
                return FALSE;
        }

        function setTitle($title = "")
        {
                $this->title = $title;
        }

        function setId($id = -1)
        {
                $this->id = $id;
        }

        function setTestId($id = -1)
        {
                $this->test_id = $id;
        }

        function setComment($comment = "")
        {
                $this->comment = $comment;
        }

        function setOutputType($outputType = OUTPUT_HTML)
        {
                $this->outputType = $outputType;
        }


        function setShuffle($shuffle = true)
        {
                if ($shuffle)
                {
                        $this->shuffle = 1;
                }
                        else
                {
                        $this->shuffle = 0;
                }
        }

        function setEstimatedWorkingTime($hour=0, $min=0, $sec=0)
        {
                $this->est_working_time = array("h" => (int)$hour, "m" => (int)$min, "s" => (int)$sec);
        }

        function keyInArray($searchkey, $array)
        {
                if ($searchKey)
                {
                        foreach ($array as $key => $value)
                        {
                                if (strcmp($key, $searchkey)==0)
                                {
                                        return true;
                                }
                        }
                }
                return false;
        }

        function setAuthor($author = "")
        {
                if (!$author)
                {
                        $author = $this->ilias->account->fullname;
                }
                $this->author = $author;
        }

        function setOwner($owner = "")
        {
                $this->owner = $owner;
        }

        function getTitle()
        {
                return $this->title;
        }

        function getId()
        {
                return $this->id;
        }

        function getShuffle()
        {
                return $this->shuffle;
        }

        function getTestId()
        {
                return $this->test_id;
        }

        function getComment()
        {
                return $this->comment;
        }

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

        function getEstimatedWorkingTime()
        {
                if (!$this->est_working_time)
                {
                        $this->est_working_time = array("h" => 0, "m" => 0, "s" => 0);
                }
                return $this->est_working_time;
        }

        function getAuthor()
        {
                return $this->author;
        }

        function getOwner()
        {
                return $this->owner;
        }

        function getObjId()
        {
                return $this->obj_id;
        }

        function setObjId($obj_id = 0)
        {
                $this->obj_id = $obj_id;
        }

        function createPageObject()
        {
                $qpl_id = $this->getObjId();

                include_once "./content/classes/Pages/class.ilPageObject.php";
                $this->page = new ilPageObject("qpl", 0);
                $this->page->setId($this->getId());
                $this->page->setParentId($qpl_id);
                $this->page->setXMLContent("<PageObject><PageContent>".
                        "<Question QRef=\"il__qst_".$this->getId()."\"/>".
                        "</PageContent></PageObject>");
                $this->page->create();
        }

        function insertIntoTest($test_id)
        {
                global $ilDB;
                
                // get maximum sequence index in test
                $query = sprintf("SELECT MAX(sequence) AS seq FROM dum_test_question WHERE test_fi=%s",
                        $ilDB->quote($test_id)
                        );
                $result = $ilDB->query($query);
                $sequence = 1;
                if ($result->numRows() == 1)
                {
                        $data = $result->fetchRow(DB_FETCHMODE_OBJECT);
                        $sequence = $data->seq + 1;
                }
                $query = sprintf("INSERT INTO dum_test_question (test_question_id, test_fi, question_fi, sequence, TIMESTAMP) VALUES (NULL, %s, %s, %s, NULL)",
                        $ilDB->quote($test_id),
                        $ilDB->quote($this->getId()),
                        $ilDB->quote($sequence)
                        );
                $result = $ilDB->query($query);
                if ($result != DB_OK)
                {
                // Fehlermeldung
                }
        }

  function _getMaximumPoints($question_id) 
        {
                global $ilDB;

                $points = 0;
                $query = sprintf("SELECT points FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        $points = $row["points"];
                }
                return $points;
  }

        function &_getQuestionInfo($question_id)
        {
                global $ilDB;

                $query = sprintf("SELECT qpl_questions.*, qpl_question_type.type_tag FROM qpl_question_type, qpl_questions WHERE qpl_questions.question_id = %s AND qpl_questions.question_type_fi = qpl_question_type.question_type_id",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        return $result->fetchRow(DB_FETCHMODE_ASSOC);
                }
                else return array();
        }
        
        function _getSuggestedSolutionCount($question_id)
        {
                global $ilDB;

                $query = sprintf("SELECT suggested_solution_id FROM qpl_suggested_solutions WHERE question_fi = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                return $result->numRows();
        }

        function &_getSuggestedSolution($question_id, $subquestion_index = 0)
        {
                global $ilDB;

                $query = sprintf("SELECT * FROM qpl_suggested_solutions WHERE question_fi = %s AND subquestion_index = %s",
                        $ilDB->quote($question_id . ""),
                        $ilDB->quote($subquestion_index . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        return array(
                                "internal_link" => $row["internal_link"],
                                "import_id" => $row["import_id"]
                        );
                }
                else
                {
                        return array();
                }
        }
        
        function _getReachedPoints($active_id, $question_id, $pass = NULL)
        {
                global $ilDB;

                $points = 0;
                if (is_null($pass))
                {
                        include_once "./assessment/classes/class.assQuestion.php";
                        $pass = assQuestion::_getSolutionMaxPass($question_id, $active_id);
                }
                $query = sprintf("SELECT * FROM tst_test_result WHERE active_fi = %s AND question_fi = %s AND pass = %s",
                        $ilDB->quote($active_id . ""),
                        $ilDB->quote($question_id . ""),
                        $ilDB->quote($pass . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        $points = $row["points"];
                }
                return $points;
        }

        function getReachedPoints($active_id, $pass = NULL)
        {
                global $ilDB;

                $points = 0;
                if (is_null($pass))
                {
                        $pass = $this->getSolutionMaxPass($active_id);
                }
                $query = sprintf("SELECT * FROM tst_test_result 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);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        $points = $row["points"];
                }
                return $points;
        }
        
        function getMaximumPoints()
        {
                return 0;
        }

        function saveWorkingData($active_id, $pass = NULL)
        {
                global $ilDB;
                global $ilUser;
                include_once "./assessment/classes/class.ilObjTest.php";
                $pass = ilObjTest::_getPass($active_id);
                $reached_points = $this->calculateReachedPoints($active_id, $pass);
                $query = sprintf("REPLACE INTO tst_test_result (active_fi, question_fi, pass, points) VALUES (%s, %s, %s, %s)",
                        $ilDB->quote($active_id . ""),
                        $ilDB->quote($this->getId() . ""),
                        $ilDB->quote($pass . ""),
                        $ilDB->quote($reached_points . "")
                );
                $result = $ilDB->query($query);
                include_once ("./classes/class.ilObjAssessmentFolder.php");
                if (ilObjAssessmentFolder::_enabledAssessmentLogging())
                {
                        $this->logAction(sprintf($this->lng->txtlng("assessment", "log_user_answered_question", ilObjAssessmentFolder::_getLogLanguage()), $reached_points), $active_id, $this->getId());
                }

                // Update objective status
                include_once 'course/classes/class.ilCourseObjectiveResult.php';

                ilCourseObjectiveResult::_updateObjectiveResult($ilUser->getId(),$active_id,$this->getId());
                
        }

        function logAction($logtext = "", $active_id = "", $question_id = "")
        {
                global $ilUser;

                $original_id = "";
                if (strcmp($question_id, "") != 0)
                {
                        include_once "./assessment/classes/class.assQuestion.php";
                        $original_id = assQuestion::_getOriginalId($question_id);
                }
                include_once "./classes/class.ilObjAssessmentFolder.php";
                include_once "./assessment/classes/class.ilObjTest.php";
                ilObjAssessmentFolder::_addLog($ilUser->id, ilObjTest::_getObjectIDFromActiveID($active_id), $logtext, $question_id, $original_id);
        }
        
        function getJavaPath() {
                return CLIENT_WEB_DIR . "/assessment/$this->obj_id/$this->id/java/";
        }

        function getImagePath()
        {
                return CLIENT_WEB_DIR . "/assessment/$this->obj_id/$this->id/images/";
        }

        function getJavaPathWeb()
        {
                include_once "./classes/class.ilUtil.php";
                $webdir = ilUtil::removeTrailingPathSeparators(CLIENT_WEB_DIR) . "/assessment/$this->obj_id/$this->id/java/";
                return str_replace(ilUtil::removeTrailingPathSeparators(ILIAS_ABSOLUTE_PATH), ilUtil::removeTrailingPathSeparators(ILIAS_HTTP_PATH), $webdir);
        }

        function getImagePathWeb()
        {
                include_once "./classes/class.ilUtil.php";
                $webdir = ilUtil::removeTrailingPathSeparators(CLIENT_WEB_DIR) . "/assessment/$this->obj_id/$this->id/images/";
                return str_replace(ilUtil::removeTrailingPathSeparators(ILIAS_ABSOLUTE_PATH), ilUtil::removeTrailingPathSeparators(ILIAS_HTTP_PATH), $webdir);
        }

        function &getSolutionValues($active_id, $pass = NULL)
        {
                global $ilDB;

                $values = array();
                
                if (is_null($pass))
                {
                        $query = sprintf("SELECT MAX(pass) AS maxpass FROM tst_test_result WHERE active_fi = %s AND question_fi = %s",
                                $ilDB->quote($active_id . ""),
                                $ilDB->quote($this->getId() . "")
                        );
                        $result = $ilDB->query($query);
                        if ($result->numRows())
                        {
                                $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                                $pass = $row["maxpass"];
                        }
                        else
                        {
                                return $values;
                        }
                }               

                $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   ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                {
                        array_push($values, $row);
                }

                return $values;
        }

        function isInUse($question_id = "")
        {
                global $ilDB;
                
                if ($question_id < 1) $question_id = $this->id;
                $query = sprintf("SELECT COUNT(question_id) AS question_count FROM qpl_questions WHERE original_id = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                $row = $result->fetchRow(DB_FETCHMODE_OBJECT);
                return $row->question_count;
        }

        function isClone($question_id = "")
        {
                global $ilDB;
                
                if ($question_id < 1) $question_id = $this->id;
                $query = sprintf("SELECT original_id FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                $row = $result->fetchRow(DB_FETCHMODE_OBJECT);
                if ($row->original_id > 0)
                {
                        return TRUE;
                }
                else
                {
                        return FALSE;
                }
        }

        function pcArrayShuffle($array)
        {
                mt_srand((double)microtime()*1000000);
                $i = count($array);
                if ($i > 0)
                {
                        while(--$i)
                        {
                                $j = mt_rand(0, $i);
                                if ($i != $j)
                                {
                                        // swap elements
                                        $tmp = $array[$j];
                                        $array[$j] = $array[$i];
                                        $array[$i] = $tmp;
                                }
                        }
                }
                return $array;
        }

        function getQuestionTypeFromDb($question_id)
        {
                global $ilDB;

                $query = sprintf("SELECT qpl_question_type.type_tag FROM qpl_question_type, qpl_questions WHERE qpl_questions.question_id = %s AND qpl_questions.question_type_fi = qpl_question_type.question_type_id",
                        $ilDB->quote($question_id));

                $result = $ilDB->query($query);
                $data = $result->fetchRow(DB_FETCHMODE_OBJECT);

                return $data->type_tag;
        }

        function getAdditionalTableName()
        {
                return "";
        }
        
        function getAnswerTableName()
        {
                return "";
        }

        function deleteAnswers($question_id)
        {
                global $ilDB;
                $answer_table_name = $this->getAnswerTableName();
                if (strlen($answer_table_name))
                {
                        $query = sprintf("DELETE FROM $answer_table_name WHERE question_fi = %s",
                                $ilDB->quote($question_id . "")
                        );
                        $result = $ilDB->query($query);
                }
        }

        function deleteAdditionalTableData($question_id)
        {
                global $ilDB;
                $additional_table_name = $this->getAdditionalTableName();
                $query = sprintf("DELETE FROM $additional_table_name WHERE question_fi = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
        }

        function delete($question_id)
        {
                global $ilDB;
                
                if ($question_id < 1)
                return;

                $query = sprintf("SELECT obj_fi FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($question_id)
                        );
        $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        $obj_id = $row["obj_fi"];
                }
                else
                {
                        return;
                }

                include_once "./content/classes/Pages/class.ilPageObject.php";
                $page = new ilPageObject("qpl", $question_id);
                $page->delete();
                
                $query = sprintf("DELETE FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($question_id)
                );
                $result = $ilDB->query($query);
                
                $this->deleteAdditionalTableData($question_id);
                $this->deleteAnswers($question_id);

                // delete the question in the tst_test_question table (list of test questions)
                $querydelete = sprintf("DELETE FROM tst_test_question WHERE question_fi = %s", $ilDB->quote($question_id));
                $deleteresult = $ilDB->query($querydelete);

                // delete suggested solutions contained in the question
                $querydelete = sprintf("DELETE FROM qpl_suggested_solutions WHERE question_fi = %s", $ilDB->quote($question_id));
                $deleteresult = $ilDB->query($querydelete);
                                
                $directory = CLIENT_WEB_DIR . "/assessment/" . $obj_id . "/$question_id";
                if (preg_match("/\d+/", $obj_id) and preg_match("/\d+/", $question_id) and is_dir($directory))
                {
                        include_once "./classes/class.ilUtil.php";
                        ilUtil::delDir($directory);
                }

                include_once("./content/classes/Media/class.ilObjMediaObject.php");
                $mobs = ilObjMediaObject::_getMobsOfObject("qpl:html", $question_id);
                // remaining usages are not in text anymore -> delete them
                // and media objects (note: delete method of ilObjMediaObject
                // checks whether object is used in another context; if yes,
                // the object is not deleted!)
                foreach($mobs as $mob)
                {
                        ilObjMediaObject::_removeUsage($mob, "qpl:html", $question_id);
                        $mob_obj =& new ilObjMediaObject($mob);
                        $mob_obj->delete();
                }
                // update question count of question pool
                include_once "./assessment/classes/class.ilObjQuestionPool.php";
                ilObjQuestionPool::_updateQuestionCount($this->obj_id);
        }

        function getTotalAnswers()
        {
                return $this->_getTotalAnswers($this->id);
        }

        function _getTotalAnswers($a_q_id)
        {
                global $ilDB;

                // get all question references to the question id
                $query = sprintf("SELECT question_id FROM qpl_questions WHERE original_id = %s OR question_id = %s",
                        $ilDB->quote($a_q_id),
                        $ilDB->quote($a_q_id)
                );

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

                if ($result->numRows() == 0)
                {
                        return 0;
                }
                $found_id = array();
                while ($row = $result->fetchRow(DB_FETCHMODE_OBJECT))
                {
                        array_push($found_id, $row->question_id);
                }

                $query = sprintf("SELECT * FROM tst_test_result WHERE question_fi IN (%s)",
                        join($found_id, ","));
                $result = $ilDB->query($query);

                return $result->numRows();
        }


        function _getTotalRightAnswers($a_q_id)
        {
                global $ilDB;
                $query = sprintf("SELECT question_id FROM qpl_questions WHERE original_id = %s OR question_id = %s",
                        $ilDB->quote($a_q_id),
                        $ilDB->quote($a_q_id)
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 0)
                {
                        return 0;
                }
                $found_id = array();
                while ($row = $result->fetchRow(DB_FETCHMODE_OBJECT))
                {
                        array_push($found_id, $row->question_id);
                }
                $query = sprintf("SELECT * FROM tst_test_result WHERE question_fi IN (%s)",
                        join($found_id, ","));
                $result = $ilDB->query($query);
                $answers = array();
                while ($row = $result->fetchRow(DB_FETCHMODE_OBJECT))
                {
                        $reached = $row->points; 
                        include_once "./assessment/classes/class.assQuestion.php";
                        $max = assQuestion::_getMaximumPoints($row->question_fi);
                        array_push($answers, array("reached" => $reached, "max" => $max));
                }
                $max = 0.0;
                $reached = 0.0;
                foreach ($answers as $key => $value)
                {
                        $max += $value["max"];
                        $reached += $value["reached"];
                }
                if ($max > 0)
                {
                        return $reached / $max;
                }
                else
                {
                        return 0;
                }
        }

        function _getTitle($a_q_id)
        {
                global $ilDB;
                $query = sprintf("SELECT title FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($a_q_id)
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        return $row["title"];
                }
                else
                {
                        return "";
                }
        }
        
        function copyXHTMLMediaObjectsOfQuestion($a_q_id)
        {
                include_once("./content/classes/Media/class.ilObjMediaObject.php");
                $mobs = ilObjMediaObject::_getMobsOfObject("qpl:html", $a_q_id);
                foreach ($mobs as $mob)
                {
                        ilObjMediaObject::_saveUsage($mob, "qpl:html", $this->getId());
                }
        }
        
        function copyPageOfQuestion($a_q_id)
        {
                if ($a_q_id > 0)
                {
                        include_once "./content/classes/Pages/class.ilPageObject.php";
                        $page = new ilPageObject("qpl", $a_q_id);

                        $xml = str_replace("il__qst_".$a_q_id, "il__qst_".$this->id,
                                $page->getXMLContent());
                        $this->page->setXMLContent($xml);
                        $this->page->saveMobUsage($xml);
                        $this->page->updateFromXML();
                }
        }

        function getPageOfQuestion()
        {
                include_once "./content/classes/Pages/class.ilPageObject.php";
                $page = new ilPageObject("qpl", $this->id);
                return $page->getXMLContent();
        }

  function _getQuestionType($question_id) {
                global $ilDB;

    if ($question_id < 1)
      return "";

    $query = sprintf("SELECT type_tag FROM qpl_questions, qpl_question_type WHERE qpl_questions.question_id = %s AND qpl_questions.question_type_fi = qpl_question_type.question_type_id",
      $ilDB->quote($question_id)
    );
    $result = $ilDB->query($query);
    if ($result->numRows() == 1) {
      $data = $result->fetchRow(DB_FETCHMODE_OBJECT);
      return $data->type_tag;
    } else {
      return "";
    }
  }

  function _getQuestionTitle($question_id) {
                global $ilDB;

    if ($question_id < 1)
      return "";

    $query = sprintf("SELECT title FROM qpl_questions WHERE qpl_questions.question_id = %s",
      $ilDB->quote($question_id)
    );
    $result = $ilDB->query($query);
    if ($result->numRows() == 1) {
      $data = $result->fetchRow(DB_FETCHMODE_ASSOC);
      return $data["title"];
    } else {
      return "";
    }
  }

        function loadFromDb($question_id)
        {
                global $ilDB;
                
                $query = sprintf("SELECT * FROM qpl_suggested_solutions WHERE question_fi = %s",
                        $ilDB->quote($this->getId() . "")
                );
                $result = $ilDB->query($query);
                $this->suggested_solutions = array();
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                        {
                                $this->suggested_solutions[$row["subquestion_index"]] = array(
                                        "internal_link" => $row["internal_link"],
                                        "import_id" => $row["import_id"]
                                );
                        }
                }
        }

        function saveToDb($original_id = "")
        {
                global $ilDB;
                
                include_once "./content/classes/Pages/class.ilInternalLink.php";
                $query = sprintf("DELETE FROM qpl_suggested_solutions WHERE question_fi = %s",
                        $ilDB->quote($this->getId() . "")
                );
                $result = $ilDB->query($query);
                ilInternalLink::_deleteAllLinksOfSource("qst", $this->getId());
                foreach ($this->suggested_solutions as $index => $solution)
                {
                        $query = sprintf("INSERT INTO qpl_suggested_solutions (suggested_solution_id, question_fi, internal_link, import_id, subquestion_index, TIMESTAMP) VALUES (NULL, %s, %s, %s, %s, NULL)",
                                $ilDB->quote($this->getId() . ""),
                                $ilDB->quote($solution["internal_link"] . ""),
                                $ilDB->quote($solution["import_id"] . ""),
                                $ilDB->quote($index . "")
                        );
                        $ilDB->query($query);
                        if (preg_match("/il_(\d*?)_(\w+)_(\d+)/", $solution["internal_link"], $matches))
                        {
                                ilInternalLink::_saveLink("qst", $this->getId(), $matches[2], $matches[3], $matches[1]);
                        }
                }
                // update question count of question pool
                include_once "./assessment/classes/class.ilObjQuestionPool.php";
                ilObjQuestionPool::_updateQuestionCount($this->obj_id);
        }
        
        function deleteSuggestedSolutions()
        {
                global $ilDB;
                // delete the links in the qpl_suggested_solutions table
                $query = sprintf("DELETE FROM qpl_suggested_solutions WHERE question_fi = %s",
                        $ilDB->quote($this->getId() . "")
                );
                $result = $ilDB->query($query);
                // delete the links in the int_link table
                include_once "./content/classes/Pages/class.ilInternalLink.php";
                ilInternalLink::_deleteAllLinksOfSource("qst", $this->getId());
        }
        
        function getSuggestedSolution($subquestion_index = 0)
        {
                if (array_key_exists($subquestion_index, $this->suggested_solutions))
                {
                        return $this->suggested_solutions[$subquestion_index];
                }
                else
                {
                        return array();
                }
        }

        function getSuggestedSolutionTitle($subquestion_index = 0)
        {
                if (array_key_exists($subquestion_index, $this->suggested_solutions))
                {
                        $title = $this->suggested_solutions[$subquestion_index]["internal_link"];
                        // TO DO: resolve internal link an get link type and title
                }
                else
                {
                        $title = "";
                }
                return $title;
        }

        function setSuggestedSolution($solution_id = "", $subquestion_index = 0, $is_import = false)
        {
                if (strcmp($solution_id, "") != 0)
                {
                        $import_id = "";
                        if ($is_import)
                        {
                                $import_id = $solution_id;
                                $solution_id = $this->_resolveInternalLink($import_id);
                        }
                        $this->suggested_solutions[$subquestion_index] = array(
                                "internal_link" => $solution_id,
                                "import_id" => $import_id
                        );
                }
        }
        
        function _resolveInternalLink($internal_link)
        {
                if (preg_match("/il_(\d+)_(\w+)_(\d+)/", $internal_link, $matches))
                {
                        include_once "./content/classes/Pages/class.ilInternalLink.php";
                        include_once "./content/classes/class.ilLMObject.php";
                        include_once "./content/classes/class.ilGlossaryTerm.php";
                        switch ($matches[2])
                        {
                                case "lm":
                                        $resolved_link = ilLMObject::_getIdForImportId($internal_link);
                                        break;
                                case "pg":
                                        $resolved_link = ilInternalLink::_getIdForImportId("PageObject", $internal_link);
                                        break;
                                case "st":
                                        $resolved_link = ilInternalLink::_getIdForImportId("StructureObject", $internal_link);
                                        break;
                                case "git":
                                        $resolved_link = ilInternalLink::_getIdForImportId("GlossaryItem", $internal_link);
                                        break;
                                case "mob":
                                        $resolved_link = ilInternalLink::_getIdForImportId("MediaObject", $internal_link);
                                        break;
                        }
                        if (strcmp($resolved_link, "") == 0)
                        {
                                $resolved_link = $internal_link;
                        }
                }
                else
                {
                        $resolved_link = $internal_link;
                }
                return $resolved_link;
        }
        
        function _resolveIntLinks($question_id)
        {
                global $ilDB;
                $resolvedlinks = 0;
                $query = sprintf("SELECT * FROM qpl_suggested_solutions WHERE question_fi = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                        {
                                $internal_link = $row["internal_link"];
                                include_once "./assessment/classes/class.assQuestion.php";
                                $resolved_link = assQuestion::_resolveInternalLink($internal_link);
                                if (strcmp($internal_link, $resolved_link) != 0)
                                {
                                        // internal link was resolved successfully
                                        $queryupdate = sprintf("UPDATE qpl_suggested_solutions SET internal_link = %s WHERE suggested_solution_id = %s",
                                                $ilDB->quote($resolved_link),
                                                $ilDB->quote($row["suggested_solution_id"] . "")
                                        );
                                        $updateresult = $ilDB->query($queryupdate);
                                        $resolvedlinks++;
                                }
                        }
                }
                if ($resolvedlinks)
                {
                        // there are resolved links -> reenter theses links to the database

                        // delete all internal links from the database
                        include_once "./content/classes/Pages/class.ilInternalLink.php";
                        ilInternalLink::_deleteAllLinksOfSource("qst", $question_id);

                        $query = sprintf("SELECT * FROM qpl_suggested_solutions WHERE question_fi = %s",
                                $ilDB->quote($question_id . "")
                        );
                        $result = $ilDB->query($query);
                        if ($result->numRows())
                        {
                                while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                                {
                                        if (preg_match("/il_(\d*?)_(\w+)_(\d+)/", $row["internal_link"], $matches))
                                        {
                                                ilInternalLink::_saveLink("qst", $question_id, $matches[2], $matches[3], $matches[1]);
                                        }
                                }
                        }
                }
        }
        
        function _getInternalLinkHref($target = "")
        {
                global $ilDB;
                $linktypes = array(
                        "lm" => "LearningModule",
                        "pg" => "PageObject",
                        "st" => "StructureObject",
                        "git" => "GlossaryItem",
                        "mob" => "MediaObject"
                );
                $href = "";
                if (preg_match("/il__(\w+)_(\d+)/", $target, $matches))
                {
                        $type = $matches[1];
                        $target_id = $matches[2];
                        include_once "./classes/class.ilUtil.php";
                        switch($linktypes[$matches[1]])
                        {
                                case "LearningModule":
                                        $href = "./goto.php?target=" . $type . "_" . $target_id;
                                        break;
                                case "PageObject":
                                case "StructureObject":
                                        $href = "./goto.php?target=" . $type . "_" . $target_id;
                                        break;
                                case "GlossaryItem":
                                        $href = "./goto.php?target=" . $type . "_" . $target_id;
                                        break;
                                case "MediaObject":
                                        $href = "./content/lm_presentation.php?obj_type=" . $linktypes[$type] . "&cmd=media&ref_id=".$_GET["ref_id"]."&mob_id=".$target_id;
                                        break;
                        }
                }
                return $href;
        }
        
        function _getOriginalId($question_id)
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() > 0)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        if ($row["original_id"] > 0)
                        {
                                return $row["original_id"];
                        }
                        else
                        {
                                return $row["question_id"];
                        }
                }
                else
                {
                        return "";
                }
        }

        function syncWithOriginal()
        {
                global $ilDB;
                
                include_once "./content/classes/Pages/class.ilInternalLink.php";
                $query = sprintf("DELETE FROM qpl_suggested_solutions WHERE question_fi = %s",
                        $ilDB->quote($this->original_id . "")
                );
                $result = $ilDB->query($query);
                ilInternalLink::_deleteAllLinksOfSource("qst", $this->original_id);
                foreach ($this->suggested_solutions as $index => $solution)
                {
                        $query = sprintf("INSERT INTO qpl_suggested_solutions (suggested_solution_id, question_fi, internal_link, import_id, subquestion_index, TIMESTAMP) VALUES (NULL, %s, %s, %s, %s, NULL)",
                                $ilDB->quote($this->original_id . ""),
                                $ilDB->quote($solution["internal_link"] . ""),
                                $ilDB->quote($solution["import_id"] . ""),
                                $ilDB->quote($index . "")
                        );
                        $ilDB->query($query);
                        if (preg_match("/il_(\d*?)_(\w+)_(\d+)/", $solution["internal_link"], $matches))
                        {
                                ilInternalLink::_saveLink("qst", $this->original_id, $matches[2], $matches[3], $matches[1]);
                        }
                }
        }

        function createRandomSolution($test_id, $user_id)
        {
        }

        function _questionExists($question_id)
        {
                global $ilDB;

                if ($question_id < 1)
                {
                        return false;
                }
                
                $query = sprintf("SELECT question_id FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($question_id)
                );
    $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        return true;
                }
                else
                {
                        return false;
                }
        }

  function &_instanciateQuestion($question_id) 
        {
                if (strcmp($question_id, "") != 0)
                {
                        include_once "./assessment/classes/class.assQuestion.php";
                        $question_type = assQuestion::_getQuestionType($question_id);
                        include_once "./assessment/classes/class.".$question_type.".php";
                        $question = new $question_type();
                        $question->loadFromDb($question_id);
                        return $question;
                }
  }
        
        function getPoints()
        {
                if (strcmp($this->points, "") == 0)
                {
                        return 0;
                }
                else
                {
                        return $this->points;
                }
        }

        
        function setPoints($a_points)
        {
                $this->points = $a_points;
        }
        
        function getSolutionCommentMCScoring($active_id)
        {
                $result = "";
                include_once "./assessment/classes/class.ilObjTest.php";
                if (ilObjTest::_getMCScoring($active_id) == SCORE_ZERO_POINTS_WHEN_UNANSWERED)
                {
                        $result = $this->lng->txt("solution_comment_mc_scoring");
                }
                return $result;
        }

        function getSolutionCommentScoreCutting($active_id)
        {
                $result = "";
                include_once "./assessment/classes/class.ilObjTest.php";
                if (ilObjTest::_getScoreCutting($active_id) == SCORE_CUT_QUESTION)
                {
                        $result = $this->lng->txt("solution_comment_score_cutting");
                }
                return $result;
        }

        function getSolutionCommentCountSystem($active_id)
        {
                $result = "";
                include_once "./assessment/classes/class.ilObjTest.php";
                if (ilObjTest::_getCountSystem($active_id) == COUNT_CORRECT_SOLUTIONS )
                {
                        $result = $this->lng->txt("solution_comment_count_system");
                }
                return $result;
        }
        
        function getSolutionMaxPass($active_id)
        {
                return $this->_getSolutionMaxPass($this->getId(), $active_id);
        }

        function _getSolutionMaxPass($question_id, $active_id)
        {
                global $ilDB;

                $query = sprintf("SELECT MAX(pass) as maxpass FROM tst_test_result WHERE active_fi = %s AND question_fi = %s",
                        $ilDB->quote($active_id . ""),
                        $ilDB->quote($question_id . "")
                );
    $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        return $row["maxpass"];
                }
                else
                {
                        return 0;
                }
        }

        function _isWriteable($question_id, $user_id)
        {
                global $ilDB;

                if (($question_id < 1) || ($user_id < 1))
                {
                        return false;
                }
                
                $query = sprintf("SELECT obj_fi FROM qpl_questions WHERE question_id = %s",
                        $ilDB->quote($question_id . "")
                );
    $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        $qpl_object_id = $row["obj_fi"];
                        include_once "./assessment/classes/class.ilObjQuestionPool.php";
                        return ilObjQuestionPool::_isWriteable($qpl_object_id, $user_id);
                }
                else
                {
                        return false;
                }
        }

        function _isUsedInRandomTest($question_id = "")
        {
                global $ilDB;
                
                if ($question_id < 1) return 0;
                $query = sprintf("SELECT test_random_question_id FROM tst_test_random_question WHERE question_fi = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                return $result->numRows();
        }

        function calculateReachedPoints($active_id, $pass = NULL, $points = 0)
        {
                include_once "./assessment/classes/class.ilObjTest.php";
                $count_system = ilObjTest::_getCountSystem($active_id);
                if ($count_system == 1)
                {
                        if ($points != $this->getMaximumPoints())
                        {
                                $points = 0;
                        }
                }
                $score_cutting = ilObjTest::_getScoreCutting($active_id);
                if ($score_cutting == 0)
                {
                        if ($points < 0)
                        {
                                $points = 0;
                        }
                }
                return $points;
        }

        function _isWorkedThrough($active_id, $question_id, $pass = NULL)
        {
                global $ilDB;

                $points = 0;
                if (is_null($pass))
                {
                        include_once "./assessment/classes/class.assQuestion.php";
                        $pass = assQuestion::_getSolutionMaxPass($question_id, $active_id);
                }
                $query = sprintf("SELECT solution_id FROM tst_solutions WHERE active_fi = %s AND question_fi = %s AND pass = %s",
                        $ilDB->quote($active_id . ""),
                        $ilDB->quote($question_id . ""),
                        $ilDB->quote($pass . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        return TRUE;
                }
                else
                {
                        return FALSE;
                }
        }

        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", $a_setting);
        }
        function _areAnswered($a_user_id,$a_question_ids)
        {
                global $ilDB;

                $query = "SELECT DISTINCT(question_fi) FROM tst_test_result JOIN tst_active ".
                        "ON (active_id = active_fi) ".
                        "WHERE question_fi IN ('".implode("','",$a_question_ids)."') ".
                        "AND user_fi = '".$a_user_id."'";
                $res = $ilDB->query($query);
                return ($res->numRows() == count($a_question_ids)) ? true : false;
        }
        
        function isHTML($a_text)
        {
                if (preg_match("/<[^>]*?>/", $a_text))
                {
                        return TRUE;
                }
                else
                {
                        return FALSE; 
                }
        }
        
        function prepareTextareaOutput($txt_output, $prepare_for_latex_output = FALSE)
        {
                include_once "./classes/class.ilObjAdvancedEditing.php";
                $result = $txt_output;
                $is_html = $this->isHTML($result);
                if ($prepare_for_latex_output)
                {
                        $result = ilUtil::insertLatexImages($result, "<span class\=\"latex\">", "<\/span>", URL_TO_LATEX);
                        $result = ilUtil::insertLatexImages($result, "\[tex\]", "\[\/tex\]", URL_TO_LATEX);
                }
                if (!$is_html)
                {
                        // if the string does not contain HTML code, replace the newlines with HTML line breaks
                        $result = preg_replace("/[\n]/", "<br />", $result);
                }
                else
                {
                        // patch for problems with the <pre> tags in tinyMCE
                        if (preg_match_all("/(<pre>.*?<\/pre>)/ims", $result, $matches))
                        {
                                foreach ($matches[0] as $found)
                                {
                                        $replacement = "";
                                        if (strpos("\n", $found) === FALSE)
                                        {
                                                $replacement = "\n";
                                        }
                                        $removed = preg_replace("/<br\s*?\/>/ims", $replacement, $found);
                                        $result = str_replace($found, $removed, $result);
                                }
                        }
                }
                $result = str_replace("{", "&#123;", $result);
                $result = str_replace("}", "&#125;", $result);
                $result = str_replace("\\", "&#92;", $result);
                return $result;
        }

        function QTIMaterialToString($a_material)
        {
                $result = "";
                for ($i = 0; $i < $a_material->getMaterialCount(); $i++)
                {
                        $material = $a_material->getMaterial($i);
                        if (strcmp($material["type"], "mattext") == 0)
                        {
                                $result .= $material["material"]->getContent();
                        }
                        if (strcmp($material["type"], "matimage") == 0)
                        {
                                $matimage = $material["material"];
                                if (preg_match("/(il_([0-9]+)_mob_([0-9]+))/", $matimage->getLabel(), $matches))
                                {
                                        // import an mediaobject which was inserted using tiny mce
                                        if (!is_array($_SESSION["import_mob_xhtml"])) $_SESSION["import_mob_xhtml"] = array();
                                        array_push($_SESSION["import_mob_xhtml"], array("mob" => $matimage->getLabel(), "uri" => $matimage->getUri()));
                                }
                        }
                }
                return $result;
        }
        
        function addQTIMaterial(&$a_xml_writer, $a_material, $close_material_tag = TRUE, $add_mobs = TRUE)
        {
                include_once "./Services/RTE/classes/class.ilRTE.php";
                include_once("./content/classes/Media/class.ilObjMediaObject.php");

                $a_xml_writer->xmlStartTag("material");
                $attrs = array(
                        "texttype" => "text/plain"
                );
                if ($this->isHTML($a_material))
                {
                        $attrs["texttype"] = "text/xhtml";
                }
                $a_xml_writer->xmlElement("mattext", $attrs, ilRTE::_replaceMediaObjectImageSrc($a_material, 0));

                if ($add_mobs)
                {
                        $mobs = ilObjMediaObject::_getMobsOfObject("qpl:html", $this->getId());
                        foreach ($mobs as $mob)
                        {
                                $mob_obj =& new ilObjMediaObject($mob);
                                $imgattrs = array(
                                        "label" => "il_" . IL_INST_ID . "_mob_" . $mob,
                                        "uri" => "objects/" . "il_" . IL_INST_ID . "_mob_" . $mob . "/" . $mob_obj->getTitle()
                                );
                                $a_xml_writer->xmlElement("matimage", $imgattrs, NULL);
                        }
                }               
                if ($close_material_tag) $a_xml_writer->xmlEndTag("material");
        }
        
        function createNewImageFileName($image_filename)
        {
                $extension = "";
                if (preg_match("/.*\.(png|jpg|gif|jpeg)$/i", $image_filename, $matches))
                {
                        $extension = "." . $matches[1];
                }
                $image_filename = md5($image_filename) . $extension;
                return $image_filename;
        }

        function &getInstances()
        {
                global $ilDB;
                $query = sprintf("SELECT question_id FROM qpl_questions WHERE original_id = %s",
                        $ilDB->quote($this->getId())
                );
                $result = $ilDB->query($query);
                $instances = array();
                $ids = array();
                while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                {
                        array_push($ids, $row["question_id"]);
                }
                foreach ($ids as $question_id)
                {
                        $query = sprintf("SELECT DISTINCT object_data.obj_id, object_data.title FROM tst_test_question, object_data, tst_tests WHERE question_fi = %s AND tst_tests.test_id = tst_test_question.test_fi AND object_data.obj_id = tst_tests.obj_fi",
                                $ilDB->quote($question_id . "")
                        );
                        $result = $ilDB->query($query);
                        while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                        {
                                $instances[$row["obj_id"]] = $row["title"];
                        }
                        $query = sprintf("SELECT DISTINCT object_data.obj_id, object_data.title FROM tst_test_random_question, tst_active, object_data, tst_tests WHERE tst_test_random_question.active_fi = tst_active.active_id AND tst_test_random_question.question_fi = %s AND tst_tests.test_id = tst_active.test_fi AND object_data.obj_id = tst_tests.obj_fi",
                                $ilDB->quote($question_id . "")
                        );
                        $result = $ilDB->query($query);
                        while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                        {
                                $instances[$row["obj_id"]] = $row["title"];
                        }
                }
                include_once "./assessment/classes/class.ilObjTest.php";
                foreach ($instances as $key => $value)
                {
                        $query = sprintf("SELECT object_reference.ref_id FROM object_reference WHERE obj_id = %s",
                                $ilDB->quote($key . "")
                        );
                        $result = $ilDB->query($query);
                        $refs = array();
                        while ($row = $result->fetchRow(DB_FETCHMODE_ASSOC))
                        {
                                array_push($refs, $row["ref_id"]);
                        }
                        $instances[$key] = array("obj_id" => $key, "title" => $value, "author" => ilObjTest::_lookupAuthor($key), "refs" => $refs);
                }
                return $instances;
        }

        function getActiveUserData($active_id)
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM tst_active WHERE active_id = %s",
                        $ilDB->quote($active_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        $row = $result->fetchRow(DB_FETCHMODE_ASSOC);
                        return array("user_id" => $row["user_fi"], "test_id" => $row["test_fi"]);
                }
                else
                {
                        return array();
                }
        }
        
}

?>