class.ilObjSurvey.php

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<?php
/*
        +-----------------------------------------------------------------------------+
        | ILIAS open source                                                           |
        +-----------------------------------------------------------------------------+
        | Copyright (c) 1998-2006 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 "./classes/class.ilObject.php";
include_once "./Modules/Survey/classes/inc.SurveyConstants.php";

class ilObjSurvey extends ilObject
{
  var $survey_id;

  var $author;

  var $introduction;

  var $outro;

  var $status;

  var $evaluation_access;

  var $start_date;

        var $startdate_enabled;

  var $end_date;

        var $enddate_enabled;

        var $questions;

        var $invitation;

        var $invitation_mode;
        
        var $anonymize;

        var $display_question_titles;

        var $surveyCodeSecurity;

        function ilObjSurvey($a_id = 0,$a_call_by_reference = true)
        {
                global $ilUser;
                $this->type = "svy";
                $this->ilObject($a_id,$a_call_by_reference);

                $this->survey_id = -1;
                $this->introduction = "";
                $this->outro = $this->lng->txt("survey_finished");
                $this->author = $ilUser->fullname;
                $this->status = STATUS_OFFLINE;
                $this->evaluation_access = EVALUATION_ACCESS_OFF;
                $this->startdate_enabled = 0;
                $this->enddate_enabled = 0;
                $this->questions = array();
                $this->invitation = INVITATION_OFF;
                $this->invitation_mode = MODE_PREDEFINED_USERS;
                $this->anonymize = ANONYMIZE_OFF;
                $this->display_question_titles = QUESTIONTITLES_VISIBLE;
                $this->surveyCodeSecurity = TRUE;
        }

        function create($a_upload = false)
        {
                parent::create();
                if(!$a_upload)
                {
                        $this->createMetaData();
                }
        }

        function createMetaData()
        {
                parent::createMetaData();
                $this->saveAuthorToMetadata();
        }

        function update()
        {
                $this->updateMetaData();

                if (!parent::update())
                {
                        return false;
                }

                // put here object specific stuff

                return true;
        }

        function createReference() 
        {
                $result = parent::createReference();
                $this->saveToDb();
                return $result;
        }

        function read($a_force_db = false)
        {
                parent::read($a_force_db);
                $this->loadFromDb();
        }
        
        function addQuestion($question_id)
        {
                array_push($this->questions, $question_id);
        }


        function delete()
        {
                $remove = parent::delete();
                // always call parent delete function first!!
                if (!$remove)
                {
                        return false;
                }

                $this->deleteMetaData();

                // Delete all survey questions, constraints and materials
                foreach ($this->questions as $question_id)
                {
                        $this->removeQuestion($question_id);
                }
                $this->deleteSurveyRecord();
                
                ilUtil::delDir($this->getImportDirectory());
                return true;
        }
        
        function deleteSurveyRecord()
        {
                global $ilDB;
                
                $query = sprintf("DELETE FROM survey_survey WHERE survey_id = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);

                $query = sprintf("SELECT questionblock_fi FROM survey_questionblock_question WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                $questionblocks = array();
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        array_push($questionblocks, $row["questionblock_fi"]);
                }
                if (count($questionblocks))
                {
                        $query = "DELETE FROM survey_questionblock WHERE questionblock_id IN ('" . join($questionblocks, "','") . "')";
                        $result = $ilDB->query($query);
                }
                $query = sprintf("DELETE FROM survey_questionblock_question WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                
                $this->deleteAllUserData();

                $query = sprintf("DELETE FROM survey_anonymous WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                
                // delete export files
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                $svy_data_dir = ilUtil::getDataDir()."/svy_data";
                $directory = $svy_data_dir."/svy_".$this->getId();
                if (is_dir($directory))
                {
                        include_once "./Services/Utilities/classes/class.ilUtil.php";
                        ilUtil::delDir($directory);
                }

                include_once("./Services/MediaObjects/classes/class.ilObjMediaObject.php");
                $mobs = ilObjMediaObject::_getMobsOfObject("svy:html", $this->getId());
                // remaining usages are not in text anymore -> delete them
                // and media objects (note: delete method of ilObjMediaObject
                // checks whether object is used in another context; if yes,
                // the object is not deleted!)
                foreach($mobs as $mob)
                {
                        ilObjMediaObject::_removeUsage($mob, "svy:html", $this->getId());
                        $mob_obj =& new ilObjMediaObject($mob);
                        $mob_obj->delete();
                }
        }
        
        function deleteAllUserData()
        {
                global $ilDB;
                
                $query = sprintf("SELECT finished_id FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                $active_array = array();
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        array_push($active_array, $row["finished_id"]);
                }

                $query = sprintf("DELETE FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);

                foreach ($active_array as $active_fi)
                {
                        $query = sprintf("DELETE FROM survey_answer WHERE active_fi = %s",
                                $ilDB->quote($active_fi)
                        );
                        $result = $ilDB->query($query);
                }
        }
        
        function removeSelectedSurveyResults($finished_ids)
        {
                global $ilDB;
                
                foreach ($finished_ids as $finished_id)
                {
                        $query = sprintf("SELECT finished_id FROM survey_finished WHERE finished_id = %s",
                                $ilDB->quote($finished_id . "")
                        );
                        $result = $ilDB->query($query);
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);

                        $query = sprintf("DELETE FROM survey_answer WHERE active_fi = %s",
                                $ilDB->quote($row["finished_id"] . "")
                        );
                        $result = $ilDB->query($query);

                        $query = sprintf("DELETE FROM survey_finished WHERE finished_id = %s",
                                $ilDB->quote($finished_id . "")
                        );
                        $result = $ilDB->query($query);
                }
        }
        
        function &getSurveyParticipants()
        {
                global $ilDB;
                
                $query = sprintf("SELECT * FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                $participants = array();
                if ($result->numRows() > 0)
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                $userdata = $this->getUserDataFromActiveId($row["finished_id"]);
                                $participants[$userdata["sortname"] . $userdata["active_id"]] = $userdata;
                        }
                }
                return $participants;
        }

        function notify($a_event,$a_ref_id,$a_parent_non_rbac_id,$a_node_id,$a_params = 0)
        {
                global $tree;
                
                switch ($a_event)
                {
                        case "link":
                                
                                //var_dump("<pre>",$a_params,"</pre>");
                                //echo "Module name ".$this->getRefId()." triggered by link event. Objects linked into target object ref_id: ".$a_ref_id;
                                //exit;
                                break;
                        
                        case "cut":
                                
                                //echo "Module name ".$this->getRefId()." triggered by cut event. Objects are removed from target object ref_id: ".$a_ref_id;
                                //exit;
                                break;
                                
                        case "copy":
                        
                                //var_dump("<pre>",$a_params,"</pre>");
                                //echo "Module name ".$this->getRefId()." triggered by copy event. Objects are copied into target object ref_id: ".$a_ref_id;
                                //exit;
                                break;

                        case "paste":
                                
                                //echo "Module name ".$this->getRefId()." triggered by paste (cut) event. Objects are pasted into target object ref_id: ".$a_ref_id;
                                //exit;
                                break;
                        
                        case "new":
                                
                                //echo "Module name ".$this->getRefId()." triggered by paste (new) event. Objects are applied to target object ref_id: ".$a_ref_id;
                                //exit;
                                break;
                }
                
                // At the beginning of the recursive process it avoids second call of the notify function with the same parameter
                if ($a_node_id==$_GET["ref_id"])
                {       
                        $parent_obj =& $this->ilias->obj_factory->getInstanceByRefId($a_node_id);
                        $parent_type = $parent_obj->getType();
                        if($parent_type == $this->getType())
                        {
                                $a_node_id = (int) $tree->getParentId($a_node_id);
                        }
                }
                
                parent::notify($a_event,$a_ref_id,$a_parent_non_rbac_id,$a_node_id,$a_params);
        }

        function isComplete()
        {
                if (($this->getTitle()) and ($this->getAuthor()) and (count($this->questions)))
                {
                        return true;
                } 
                        else 
                {
                        return false;
                }
        }

        function _isComplete($obj_id)
        {
                $survey = new ilObjSurvey($obj_id, false);
                $survey->loadFromDb();
                if (($survey->getTitle()) and ($survey->getAuthor()) and (count($survey->questions)))
                {
                        return true;
                } 
                        else 
                {
                        return false;
                }
        }

        function &_getGlobalSurveyData($obj_id)
        {
                $survey = new ilObjSurvey($obj_id, false);
                $survey->loadFromDb();
                $result = array();
                if (($survey->getTitle()) and ($survey->author) and (count($survey->questions)))
                {
                        $result["complete"] = true;
                } 
                        else 
                {
                        $result["complete"] = false;
                }
                $result["evaluation_access"] = $survey->getEvaluationAccess();
                return $result;
        }

        function saveCompletionStatus() 
        {
                global $ilDB;
                
                $complete = 0;
                if ($this->isComplete()) 
                {
                        $complete = 1;
                }
    if ($this->survey_id > 0) 
                {
                        $query = sprintf("UPDATE survey_survey SET complete = %s WHERE survey_id = %s",
                                $ilDB->quote("$complete"),
                                $ilDB->quote($this->survey_id) 
                        );
      $result = $ilDB->query($query);
                }
        }

        function duplicateQuestionForSurvey($question_id)
        {
                global $ilUser;
                
                $questiontype = $this->getQuestionType($question_id);
                $question_gui = $this->getQuestionGUI($questiontype, $question_id);
                $duplicate_id = $question_gui->object->duplicate(true);
                return $duplicate_id;
        }

        function insertQuestion($question_id) 
        {
                global $ilDB;
                
                include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                if (!SurveyQuestion::_isComplete($question_id))
                {
                        return FALSE;
                }
                else
                {
                        // get maximum sequence index in test
                        $query = sprintf("SELECT survey_question_id FROM survey_survey_question WHERE survey_fi = %s",
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                        $sequence = $result->numRows();
                        $duplicate_id = $this->duplicateQuestionForSurvey($question_id);
                        $query = sprintf("INSERT INTO survey_survey_question (survey_question_id, survey_fi, question_fi, sequence, TIMESTAMP) VALUES (NULL, %s, %s, %s, NULL)",
                                $ilDB->quote($this->getSurveyId()),
                                $ilDB->quote($duplicate_id),
                                $ilDB->quote($sequence)
                        );
                        $result = $ilDB->query($query);
                        if (PEAR::isError($result)) 
                        {
                                global $ilias;
                                $ilias->raiseError($result->getMessage());
                        }
                        $this->loadQuestionsFromDb();
                        return TRUE;
                }
        }


        
        function insertQuestionblock($questionblock_id) 
        {
                global $ilDB;
                $query = sprintf("SELECT survey_questionblock.title, survey_questionblock.show_questiontext, survey_questionblock_question.question_fi FROM survey_questionblock, survey_questionblock_question, survey_survey_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_survey_question.question_fi = survey_questionblock_question.question_fi AND survey_questionblock.questionblock_id = %s ORDER BY survey_survey_question.sequence",
                        $ilDB->quote($questionblock_id)
                );
                $result = $ilDB->query($query);
                $questions = array();
                $show_questiontext = 0;
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        $duplicate_id = $this->duplicateQuestionForSurvey($row["question_fi"]);
                        array_push($questions, $duplicate_id);
                        $title = $row["title"];
                        $show_questiontext = $row["show_questiontext"];
                }
                $this->createQuestionblock($title, $show_questiontext, $questions);
        }
        
        function getAllRTEContent()
        {
                $result = array();
                array_push($result, $this->getIntroduction());
                array_push($result, $this->getOutro());
                return $result;
        }
        
        function cleanupMediaobjectUsage()
        {
                include_once("./Services/RTE/classes/class.ilRTE.php");
                $completecontent = "";
                foreach ($this->getAllRTEContent() as $content)
                {
                        $completecontent .= $content;
                }
                ilRTE::_cleanupMediaObjectUsage($completecontent, $this->getType() . ":html",
                        $this->getId());
        }

  function saveToDb()
  {
                global $ilDB;
                $complete = 0;
                if ($this->isComplete()) 
                {
                        $complete = 1;
                }
                $startdate = $this->getStartDate();
                if (!$startdate or !$this->startdate_enabled)
                {
                        $startdate = "NULL";
                }
                else
                {
                        $startdate = $ilDB->quote($startdate);
                }
                $enddate = $this->getEndDate();
                if (!$enddate or !$this->enddate_enabled)
                {
                        $enddate = "NULL";
                }
                else
                {
                        $enddate = $ilDB->quote($enddate);
                }

                // cleanup RTE images
                $this->cleanupMediaobjectUsage();

    if ($this->survey_id == -1) 
                {
      // Write new dataset
      $now = getdate();
      $created = sprintf("%04d%02d%02d%02d%02d%02d", $now['year'], $now['mon'], $now['mday'], $now['hours'], $now['minutes'], $now['seconds']);
      $query = sprintf("INSERT INTO survey_survey (survey_id, obj_fi, author, introduction, outro, status, startdate, enddate, evaluation_access, invitation, invitation_mode, complete, created, anonymize, show_question_titles, TIMESTAMP) VALUES (NULL, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, NULL)",
                                $ilDB->quote($this->getId()),
                                $ilDB->quote($this->author . ""),
                                $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($this->introduction, 0)),
                                $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($this->getOutro(), 0)),
                                $ilDB->quote($this->status . ""),
                                $startdate,
                                $enddate,
                                $ilDB->quote($this->evaluation_access . ""),
                                $ilDB->quote($this->invitation . ""),
                                $ilDB->quote($this->invitation_mode . ""),
                                $ilDB->quote($complete . ""),
                                $ilDB->quote($this->getAnonymize() . ""),
                                $ilDB->quote($this->getShowQuestionTitles() . ""),
                                $ilDB->quote($created)
                        );
                        $result = $ilDB->query($query);
                        if (PEAR::isError($result)) 
                        {
                                global $ilias;
                                $ilias->raiseError($result->getMessage());
                        }
                        else
                        {
                                $this->survey_id = $ilDB->getLastInsertId();
                        }
                } 
                else 
                {
                        // update existing dataset
                        $query = sprintf("UPDATE survey_survey SET author = %s, introduction = %s, outro = %s, status = %s, startdate = %s, enddate = %s, evaluation_access = %s, invitation = %s, invitation_mode = %s, complete = %s, anonymize = %s, show_question_titles = %s WHERE survey_id = %s",
                                $ilDB->quote($this->author . ""),
                                $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($this->introduction, 0)),
                                $ilDB->quote(ilRTE::_replaceMediaObjectImageSrc($this->getOutro(), 0)),
                                $ilDB->quote($this->status . ""),
                                $startdate,
                                $enddate,
                                $ilDB->quote($this->evaluation_access . ""),
                                $ilDB->quote($this->invitation . ""),
                                $ilDB->quote($this->invitation_mode . ""),
                                $ilDB->quote($complete . ""),
                                $ilDB->quote($this->getAnonymize() . ""),
                                $ilDB->quote($this->getShowQuestionTitles() . ""),
                                $ilDB->quote($this->survey_id)
                        );
                        $result = $ilDB->query($query);
                }
                if (PEAR::isError($result)) 
                {
                        global $ilias;
                        $ilias->raiseError($result->getMessage());
                }
                else
                {
                        // save questions to db
                        $this->saveQuestionsToDb();
                }
        }

        function saveQuestionsToDb() 
        {
                global $ilDB;
                // save old questions state
                $old_questions = array();
                $query = sprintf("SELECT * FROM survey_survey_question WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                $old_questions[$row["question_fi"]] = $row;
                        }
                }
                
                // delete existing question relations
    $query = sprintf("DELETE FROM survey_survey_question WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                // create new question relations
                foreach ($this->questions as $key => $value) 
                {
                        $query = sprintf("INSERT INTO survey_survey_question (survey_question_id, survey_fi, question_fi, heading, sequence, TIMESTAMP) VALUES (NULL, %s, %s, %s, %s, NULL)",
                                $ilDB->quote($this->getSurveyId() . ""),
                                $ilDB->quote($value . ""),
                                $ilDB->quote($old_questions[$value]["heading"]),
                                $ilDB->quote($key . "")
                        );
                        $result = $ilDB->query($query);
                }
        }

        function getAnonymousId($id)
        {
                global $ilDB;
                $query = sprintf("SELECT anonymous_id FROM survey_finished WHERE anonymous_id = %s",
                        $ilDB->quote($id)
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        return $row["anonymous_id"];
                }
                else
                {
                        return "";
                }
        }

        function getQuestionGUI($questiontype, $question_id)
        {
                include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestionGUI.php";
                return SurveyQuestionGUI::_getQuestionGUI($questiontype, $question_id);
        }
        
  function getQuestionType($question_id) 
        {
                global $ilDB;
    if ($question_id < 1) return -1;
    $query = sprintf("SELECT type_tag FROM survey_question, survey_questiontype WHERE survey_question.question_id = %s AND survey_question.questiontype_fi = survey_questiontype.questiontype_id",
      $ilDB->quote($question_id)
    );
    $result = $ilDB->query($query);
    if ($result->numRows() == 1) 
                {
      $data = $result->fetchRow(MDB2_FETCHMODE_OBJECT);
      return $data->type_tag;
    } 
                else 
                {
      return "";
    }
  }
        
        function getSurveyId()
        {
                return $this->survey_id;
        }
        
        function setAnonymize($a_anonymize)
        {
                $this->anonymize = $a_anonymize;
        }

        function getAnonymize()
        {
                return $this->anonymize;
        }
        
        function isAccessibleWithoutCode()
        {
                if ($this->getAnonymize() == ANONYMIZE_FREEACCESS)
                {
                        return true;
                }
                else
                {
                        return false;
                }
        }

        function loadFromDb()
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM survey_survey WHERE obj_fi = %s",
                        $ilDB->quote($this->getId())
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1) 
                {
                        $data = $result->fetchRow(MDB2_FETCHMODE_OBJECT);
                        $this->survey_id = $data->survey_id;
                        if (strlen($this->getAuthor()) == 0)
                        {
                                $this->saveAuthorToMetadata($data->author);
                        }
                        $this->author = $this->getAuthor();
                        include_once("./Services/RTE/classes/class.ilRTE.php");
                        $this->introduction = ilRTE::_replaceMediaObjectImageSrc($data->introduction, 1);
                        if (strcmp($data->outro, "survey_finished") == 0)
                        {
                                $this->setOutro($this->lng->txt("survey_finished"));
                        }
                        else
                        {
                                $this->setOutro(ilRTE::_replaceMediaObjectImageSrc($data->outro, 1));
                        }
                        $this->status = $data->status;
                        $this->invitation = $data->invitation;
                        $this->invitation_mode = $data->invitation_mode;
                        $this->display_question_titles = $data->show_question_titles;
                        $this->start_date = $data->startdate;
                        if (!$data->startdate)
                        {
                                $this->startdate_enabled = 0;
                        }
                        else
                        {
                                $this->startdate_enabled = 1;
                        }
                        $this->end_date = $data->enddate;
                        if (!$data->enddate)
                        {
                                $this->enddate_enabled = 0;
                        }
                        else
                        {
                                $this->enddate_enabled = 1;
                        }
                        switch ($data->anonymize)
                        {
                                case ANONYMIZE_OFF:
                                case ANONYMIZE_ON:
                                case ANONYMIZE_FREEACCESS:
                                        $this->setAnonymize($data->anonymize);
                                        break;
                                default:
                                        $this->setAnonymize(ANONYMIZE_OFF);
                                        break;
                        }
                        $this->evaluation_access = $data->evaluation_access;
                        $this->loadQuestionsFromDb();
                }
        }

        function loadQuestionsFromDb() 
        {
                global $ilDB;
                $this->questions = array();
                $query = sprintf("SELECT * FROM survey_survey_question WHERE survey_fi = %s ORDER BY sequence",
                        $ilDB->quote($this->survey_id)
                );
                $result = $ilDB->query($query);
                while ($data = $result->fetchRow(MDB2_FETCHMODE_OBJECT)) 
                {
                        $this->questions[$data->sequence] = $data->question_fi;
                }
        }

        function setStartDateEnabled($enabled = false)
        {
                if ($enabled)
                {
                        $this->startdate_enabled = 1;
                }
                else
                {
                        $this->startdate_enabled = 0;
                }
        }
        
        function getStartDateEnabled()
        {
                return $this->startdate_enabled;
        }

        function setEndDateEnabled($enabled = false)
        {
                if ($enabled)
                {
                        $this->enddate_enabled = 1;
                }
                else
                {
                        $this->enddate_enabled = 0;
                }
        }
        
        function getEndDateEnabled()
        {
                return $this->enddate_enabled;
        }

  function setAuthor($author = "") 
        {
    $this->author = $author;
  }

        function saveAuthorToMetadata($a_author = "")
        {
                $md =& new ilMD($this->getId(), 0, $this->getType());
                $md_life =& $md->getLifecycle();
                if (!$md_life)
                {
                        if (strlen($a_author) == 0)
                        {
                                global $ilUser;
                                $a_author = $ilUser->getFullname();
                        }
                        
                        $md_life =& $md->addLifecycle();
                        $md_life->save();
                        $con =& $md_life->addContribute();
                        $con->setRole("Author");
                        $con->save();
                        $ent =& $con->addEntity();
                        $ent->setEntity($a_author);
                        $ent->save();
                }
        }
        
  function getAuthor() 
        {
                $author = array();
                include_once "./Services/MetaData/classes/class.ilMD.php";
                $md =& new ilMD($this->getId(), 0, $this->getType());
                $md_life =& $md->getLifecycle();
                if ($md_life)
                {
                        $ids =& $md_life->getContributeIds();
                        foreach ($ids as $id)
                        {
                                $md_cont =& $md_life->getContribute($id);
                                if (strcmp($md_cont->getRole(), "Author") == 0)
                                {
                                        $entids =& $md_cont->getEntityIds();
                                        foreach ($entids as $entid)
                                        {
                                                $md_ent =& $md_cont->getEntity($entid);
                                                array_push($author, $md_ent->getEntity());
                                        }
                                }
                        }
                }
                return join($author, ",");
  }

  function getShowQuestionTitles() 
        {
                return $this->display_question_titles;
  }

  function showQuestionTitles() 
        {
                $this->display_question_titles = QUESTIONTITLES_VISIBLE;
  }

  function hideQuestionTitles() 
        {
                $this->display_question_titles = QUESTIONTITLES_HIDDEN;
  }
        
  function setInvitation($invitation = 0) 
        {
                global $ilDB;
                global $ilAccess;
    $this->invitation = $invitation;
                // remove the survey from the personal desktops
                $query = sprintf("DELETE FROM desktop_item WHERE type = %s AND item_id = %s",
                        $ilDB->quote("svy"),
                        $ilDB->quote($this->getRefId())
                );
                $result = $ilDB->query($query);
                if ($invitation == INVITATION_OFF)
                {
                        // already removed prior
                }
                else if ($invitation == INVITATION_ON)
                {
                        if ($this->getInvitationMode() == MODE_UNLIMITED)
                        {
                                $query = "SELECT usr_id FROM usr_data";
                                $result = $ilDB->query($query);
                                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                                {
                                        if ($ilAccess->checkAccessOfUser($row["usr_id"], "read", "", $this->getRefId(), "svy", $this->getId()))
                                        {
                                                $query = sprintf("INSERT INTO desktop_item (user_id, item_id, type, parameters) VALUES (%s, %s, %s, NULL)",
                                                        $ilDB->quote($row["usr_id"]),
                                                        $ilDB->quote($this->getRefId()),
                                                        $ilDB->quote("svy")
                                                );
                                                $insertresult = $ilDB->query($query);
                                        }
                                }
                        }
                        else
                        {
                                $query = sprintf("SELECT user_fi FROM survey_invited_user WHERE survey_fi = %s",
                                        $ilDB->quote($this->getSurveyId())
                                );
                                $result = $ilDB->query($query);
                                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                                {
                                        $query = sprintf("INSERT INTO desktop_item (user_id, item_id, type, parameters) VALUES (%s, %s, %s, NULL)",
                                                $ilDB->quote($row["user_fi"]),
                                                $ilDB->quote($this->getRefId()),
                                                $ilDB->quote("svy")
                                        );
                                        $insertresult = $ilDB->query($query);
                                }
                                $query = sprintf("SELECT group_fi FROM survey_invited_group WHERE survey_fi = %s",
                                        $ilDB->quote($this->getSurveyId())
                                );
                                $result = $ilDB->query($query);
                                include_once "./Modules/Group/classes/class.ilObjGroup.php";
                                include_once './Services/User/classes/class.ilObjUser.php';
                                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                                {
                                        $group = new ilObjGroup($row["group_fi"]);
                                        $members = $group->getGroupMemberIds();
                                        foreach ($members as $user_id)
                                        {
                                                if (ilObjUser::_lookupLogin($user_id))
                                                {
                                                        $user = new ilObjUser($user_id);
                                                        $user->addDesktopItem($this->getRefId(), "svy");
                                                }
                                        }
                                }
                        }
                }
  }

  function setInvitationMode($invitation_mode = 0) 
        {
                global $ilDB;
    $this->invitation_mode = $invitation_mode;
                if ($invitation_mode == MODE_UNLIMITED)
                {
                        $query = sprintf("DELETE FROM survey_invited_group WHERE survey_fi = %s",
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                        $query = sprintf("DELETE FROM survey_invited_user WHERE survey_fi = %s",
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                }
                // add/remove the survey from personal desktops -> calling getInvitation with the same value makes all changes for the new invitation mode
                $this->setInvitation($this->getInvitation());
  }
        
        function setInvitationAndMode($invitation = 0, $invitation_mode = 0)
        {
                global $ilDB;
    $this->invitation_mode = $invitation_mode;
                if ($invitation_mode == MODE_UNLIMITED)
                {
                        $query = sprintf("DELETE FROM survey_invited_group WHERE survey_fi = %s",
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                        $query = sprintf("DELETE FROM survey_invited_user WHERE survey_fi = %s",
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                }
                // add/remove the survey from personal desktops -> calling getInvitation with the same value makes all changes for the new invitation mode
                $this->setInvitation($invitation);
        }

  function setIntroduction($introduction = "") 
        {
    $this->introduction = $introduction;
  }

  function setOutro($outro = "") 
        {
    $this->outro = $outro;
  }

  function getInvitation() 
        {
    return $this->invitation;
  }

        function getInvitationMode() 
        {
                include_once "./Services/Administration/classes/class.ilSetting.php";
                $surveySetting = new ilSetting("survey");
                $unlimited_invitation = $surveySetting->get("unlimited_invitation");
                if (!$unlimited_invitation && $this->invitation_mode == MODE_UNLIMITED)
                {
                        return MODE_PREDEFINED_USERS;
                }
                else
                {
                        return $this->invitation_mode;
                }
        }

  function getStatus() 
        {
    return $this->status;
  }

  function isOnline() 
        {
    if ($this->status == STATUS_ONLINE)
                {
                        return true;
                }
                else
                {
                        return false;
                }
  }

  function isOffline() 
        {
    if ($this->status == STATUS_OFFLINE)
                {
                        return true;
                }
                else
                {
                        return false;
                }
  }

  function setStatus($status = STATUS_OFFLINE) 
        {
                $result = "";
                if (($status == STATUS_ONLINE) && (count($this->questions) == 0))
                {
        $this->status = STATUS_OFFLINE;
                        $result = $this->lng->txt("cannot_switch_to_online_no_questions");
                }
                else
                {
        $this->status = $status;
                }
                return $result;
  }

  function getStartDate() 
        {
    return $this->start_date;
  }

        function canStartSurvey($anonymous_id = NULL)
        {
                global $ilAccess;
                
                $result = TRUE;
                $messages = array();
                // check start date
                if ($this->getStartDateEnabled())
                {
                        $epoch_time = mktime(0, 0, 0, $this->getStartMonth(), $this->getStartDay(), $this->getStartYear());
                        $now = mktime();
                        if ($now < $epoch_time) 
                        {
                                array_push($messages,$this->lng->txt('start_date_not_reached').' ('.
                                        ilDatePresentation::formatDate(
                                                new ilDate($this->getStartYear().$this->getStartMonth().$this->getStartDay()."000000",IL_CAL_TIMESTAMP)). ")");
                                $result = FALSE;
                        }
                }
                // check end date
                if ($this->getEndDateEnabled())
                {
                        $epoch_time = mktime(0, 0, 0, $this->getEndMonth(), $this->getEndDay(), $this->getEndYear());
                        $now = mktime();
                        if ($now > $epoch_time) 
                        {
                                array_push($messages,$this->lng->txt('end_date_reached').' ('.
                                        ilDatePresentation::formatDate(
                                                new ilDate($this->getEndYear().$this->getEndMonth().$this->getEndDay()."000000",IL_CAL_TIMESTAMP)). ")");
                                $result = FALSE;
                        }
                }
                // check online status
                if ($this->getStatus() == STATUS_OFFLINE)
                {
                        array_push($messages, $this->lng->txt("survey_is_offline"));
                        $result = FALSE;
                }
                // check rbac permissions
                if (!$ilAccess->checkAccess("read", "", $this->ref_id))
                {
                        array_push($messages, $this->lng->txt("cannot_participate_survey"));
                        $result = FALSE;
                }
                // 2. check previous access
                if (!$result["error"])
                {
                        global $ilUser;
                        $survey_started = $this->isSurveyStarted($ilUser->getId(), $anonymous_id);
                        if ($survey_started === 1)
                        {
                                array_push($messages, $this->lng->txt("already_completed_survey"));
                                $result = FALSE;
                        }
                }
                return array(
                        "result" => $result,
                        "messages" => $messages
                );
        }

  function setStartDate($start_date = "") 
        {
    $this->start_date = $start_date;
  }

  function getStartMonth() 
        {
                if (preg_match("/(\d{4})-(\d{2})-(\d{2})/", $this->start_date, $matches))
                {
                        return $matches[2];
                }
                else
                {
                        return "";
                }
  }

  function getStartDay() 
        {
                if (preg_match("/(\d{4})-(\d{2})-(\d{2})/", $this->start_date, $matches))
                {
                        return $matches[3];
                }
                else
                {
                        return "";
                }
  }

  function getStartYear() 
        {
                if (preg_match("/(\d{4})-(\d{2})-(\d{2})/", $this->start_date, $matches))
                {
                        return $matches[1];
                }
                else
                {
                        return "";
                }
  }

  function getEndDate() 
        {
    return $this->end_date;
  }

  function setEndDate($end_date = "") 
        {
    $this->end_date = $end_date;
  }

  function getEndMonth() 
        {
                if (preg_match("/(\d{4})-(\d{2})-(\d{2})/", $this->end_date, $matches))
                {
                        return $matches[2];
                }
                else
                {
                        return "";
                }
  }

  function getEndDay() 
        {
                if (preg_match("/(\d{4})-(\d{2})-(\d{2})/", $this->end_date, $matches))
                {
                        return $matches[3];
                }
                else
                {
                        return "";
                }
  }

  function getEndYear() 
        {
                if (preg_match("/(\d{4})-(\d{2})-(\d{2})/", $this->end_date, $matches))
                {
                        return $matches[1];
                }
                else
                {
                        return "";
                }
  }

  function getEvaluationAccess() 
        {
    return $this->evaluation_access;
  }

  function setEvaluationAccess($evaluation_access = EVALUATION_ACCESS_OFF) 
        {
    $this->evaluation_access = $evaluation_access;
  }

  function getIntroduction() 
        {
    return $this->introduction;
  }

  function getOutro() 
        {
    return $this->outro;
  }

        function &getExistingQuestions() 
        {
                global $ilDB;
                $existing_questions = array();
                $query = sprintf("SELECT survey_question.original_id FROM survey_question, survey_survey_question WHERE survey_survey_question.survey_fi = %s AND survey_survey_question.question_fi = survey_question.question_id",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                while ($data = $result->fetchRow(MDB2_FETCHMODE_OBJECT)) 
                {
                        array_push($existing_questions, $data->original_id);
                }
                return $existing_questions;
        }

        function &getQuestionpoolTitles($could_be_offline = FALSE, $showPath = FALSE) 
        {
                include_once "./Modules/SurveyQuestionPool/classes/class.ilObjSurveyQuestionPool.php";
                return ilObjSurveyQuestionPool::_getAvailableQuestionpools($use_object_id = TRUE, $could_be_offline, $showPath);
        }
        
        function moveUpQuestion($question_id)
        {
                $move_questions = array($question_id);
                $pages =& $this->getSurveyPages();
                $pageindex = -1;
                foreach ($pages as $idx => $page)
                {
                        if ($page[0]["question_id"] == $question_id)
                        {
                                $pageindex = $idx;
                        }
                }
                if ($pageindex > 0)
                {
                        $this->moveQuestions($move_questions, $pages[$pageindex-1][0]["question_id"], 0);
                }
                else
                {
                        // move up a question in a questionblock
                        $questions = $this->getSurveyQuestions();
                        $questions = array_keys($questions);
                        $index = array_search($question_id, $questions);
                        if (($index !== FALSE) && ($index > 0))
                        {
                                $this->moveQuestions($move_questions, $questions[$index-1], 0);
                        }
                }
        }
        
        function moveDownQuestion($question_id)
        {
                $move_questions = array($question_id);
                $pages =& $this->getSurveyPages();
                $pageindex = -1;
                foreach ($pages as $idx => $page)
                {
                        if (($page[0]["question_id"] == $question_id) && (strcmp($page[0]["questionblock_id"], "") == 0))
                        {
                                $pageindex = $idx;
                        }
                }
                if (($pageindex < count($pages)-1) && ($pageindex >= 0))
                {
                        $this->moveQuestions($move_questions, $pages[$pageindex+1][count($pages[$pageindex+1])-1]["question_id"], 1);
                }
                else
                {
                        // move down a question in a questionblock
                        $questions = $this->getSurveyQuestions();
                        $questions = array_keys($questions);
                        $index = array_search($question_id, $questions);
                        if (($index !== FALSE) && ($index < count($questions)-1))
                        {
                                $this->moveQuestions($move_questions, $questions[$index+1], 1);
                        }
                }
        }
        
        function moveUpQuestionblock($questionblock_id)
        {
                $pages =& $this->getSurveyPages();
                $move_questions = array();
                $pageindex = -1;
                foreach ($pages as $idx => $page)
                {
                        if ($page[0]["questionblock_id"] == $questionblock_id)
                        {
                                foreach ($page as $pageidx => $question)
                                {
                                        array_push($move_questions, $question["question_id"]);
                                }
                                $pageindex = $idx;
                        }
                }
                if ($pageindex > 0)
                {
                        $this->moveQuestions($move_questions, $pages[$pageindex-1][0]["question_id"], 0);
                }
        }
        
        function moveDownQuestionblock($questionblock_id)
        {
                $pages =& $this->getSurveyPages();
                $move_questions = array();
                $pageindex = -1;
                foreach ($pages as $idx => $page)
                {
                        if ($page[0]["questionblock_id"] == $questionblock_id)
                        {
                                foreach ($page as $pageidx => $question)
                                {
                                        array_push($move_questions, $question["question_id"]);
                                }
                                $pageindex = $idx;
                        }
                }
                if ($pageindex < count($pages)-1)
                {
                        $this->moveQuestions($move_questions, $pages[$pageindex+1][count($pages[$pageindex+1])-1]["question_id"], 1);
                }
        }
        
        function moveQuestions($move_questions, $target_index, $insert_mode)
        {
                $array_pos = array_search($target_index, $this->questions);
                if ($insert_mode == 0)
                {
                        $part1 = array_slice($this->questions, 0, $array_pos);
                        $part2 = array_slice($this->questions, $array_pos);
                }
                else if ($insert_mode == 1)
                {
                        $part1 = array_slice($this->questions, 0, $array_pos + 1);
                        $part2 = array_slice($this->questions, $array_pos + 1);
                }
                foreach ($move_questions as $question_id)
                {
                        if (!(array_search($question_id, $part1) === FALSE))
                        {
                                unset($part1[array_search($question_id, $part1)]);
                        }
                        if (!(array_search($question_id, $part2) === FALSE))
                        {
                                unset($part2[array_search($question_id, $part2)]);
                        }
                }
                $part1 = array_values($part1);
                $part2 = array_values($part2);
                $this->questions = array_values(array_merge($part1, $move_questions, $part2));
                foreach ($move_questions as $question_id)
                {
                        $constraints = $this->getConstraints($question_id);
                        foreach ($constraints as $idx => $constraint)
                        {
                                foreach ($part2 as $next_question_id)
                                {
                                        if ($constraint["question"] == $next_question_id)
                                        {
                                                // constraint concerning a question that follows -> delete constraint
                                                $this->deleteConstraint($constraint["id"], $question_id);
                                        }
                                }
                        }
                }
                $this->saveQuestionsToDb();
        }
        
        function removeQuestion($question_id)
        {
                include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                $question =& $this->_instanciateQuestion($question_id);
                $question->delete($question_id);
                $this->removeConstraintsConcerningQuestion($question_id);
        }
        
        function removeConstraintsConcerningQuestion($question_id)
        {
                global $ilDB;
                $query = sprintf("SELECT constraint_fi FROM survey_question_constraint WHERE question_fi = %s AND survey_fi = %s",
                        $ilDB->quote($question_id . ""),
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() > 0)
                {
                        $remove_constraints = array();
                        while ($row = $result->fetchRow(DB_FETCHMODE_HASHREF))
                        {
                                array_push($remove_constraints, $row["constraint_fi"]);
                        }
                        $query = sprintf("DELETE FROM survey_question_constraint WHERE question_fi = %s AND survey_fi = %s",
                                $ilDB->quote($question_id . ""),
                                $ilDB->quote($this->getSurveyId() . "")
                        );
                        $result = $ilDB->query($query);
                        foreach ($remove_constraints as $key => $constraint_id)
                        {
                                $query = sprintf("DELETE FROM survey_constraint WHERE constraint_id = %s",
                                        $ilDB->quote($constraint_id . "")
                                );
                                $result = $ilDB->query($query);
                        }
                }
        }
                
        function removeQuestions($remove_questions, $remove_questionblocks)
        {
                global $ilDB;
                $questions =& $this->getSurveyQuestions();
                foreach ($questions as $question_id => $data)
                {
                        if (in_array($question_id, $remove_questions) or in_array($data["questionblock_id"], $remove_questionblocks))
                        {
                                unset($this->questions[array_search($question_id, $this->questions)]);
                                $this->removeQuestion($question_id);
                        }
                }
                foreach ($remove_questionblocks as $questionblock_id)
                {
                        $query = sprintf("DELETE FROM survey_questionblock WHERE questionblock_id = %s",
                                $ilDB->quote($questionblock_id)
                        );
                        $result = $ilDB->query($query);
                        $query = sprintf("DELETE FROM survey_questionblock_question WHERE questionblock_fi = %s AND survey_fi = %s",
                                $ilDB->quote($questionblock_id),
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                }
                $this->questions = array_values($this->questions);
                $this->saveQuestionsToDb();
        }
                
        function unfoldQuestionblocks($questionblocks)
        {
                global $ilDB;
                foreach ($questionblocks as $index)
                {
                        $query = sprintf("DELETE FROM survey_questionblock WHERE questionblock_id = %s",
                                $ilDB->quote($index)
                        );
                        $result = $ilDB->query($query);
                        $query = sprintf("DELETE FROM survey_questionblock_question WHERE questionblock_fi = %s AND survey_fi = %s",
                                $ilDB->quote($index),
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                }
        }
        
        function &getQuestionblockTitles()
        {
                global $ilDB;
                $titles = array();
                $query = sprintf("SELECT survey_questionblock.* FROM survey_questionblock, survey_question, survey_questionblock_question WHERE survey_questionblock_question.question_fi = survey_question.question_id AND survey_question.obj_fi = %s",
                        $ilDB->quote($this->getId())
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {
                        $titles[$row->questionblock_id] = $row->title;
                }
                return $titles;
        }
        
        function &getQuestionblockQuestions($questionblock_id)
        {
                global $ilDB;
                $titles = array();
                $query = sprintf("SELECT survey_question.title, survey_questionblock_question.question_fi, survey_questionblock_question.survey_fi FROM survey_questionblock, survey_questionblock_question, survey_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_question.question_id = survey_questionblock_question.question_fi AND survey_questionblock.questionblock_id = %s",
                        $ilDB->quote($questionblock_id)
                );
                $result = $ilDB->query($query);
                $survey_id = "";
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        $titles[$row["question_fi"]] = $row["title"];
                        $survey_id = $row["survey_fi"];
                }
                $query = sprintf("SELECT question_fi, sequence FROM survey_survey_question WHERE survey_fi = %s ORDER BY sequence",
                        $ilDB->quote($survey_id . "")
                );
                $result = $ilDB->query($query);
                $resultarray = array();
                $counter = 1;
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        if (array_key_exists($row["question_fi"], $titles))
                        {
                                $resultarray[$counter++] = $titles[$row["question_fi"]];
                        }
                }
                return $resultarray;
        }
        
        function &getQuestionblockQuestionIds($questionblock_id)
        {
                global $ilDB;
                $ids = array();
                $query = sprintf("SELECT survey_questionblock.*, survey_survey.obj_fi, survey_question.question_id AS questiontitle, survey_survey_question.sequence, object_data.title as surveytitle, survey_question.question_id FROM object_reference, object_data, survey_questionblock, survey_questionblock_question, survey_survey, survey_question, survey_survey_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_survey.survey_id = survey_questionblock_question.survey_fi AND survey_questionblock_question.question_fi = survey_question.question_id AND survey_survey.obj_fi = object_reference.obj_id AND object_reference.obj_id = object_data.obj_id AND survey_survey_question.survey_fi = survey_survey.survey_id AND survey_survey_question.question_fi = survey_question.question_id AND survey_survey.obj_fi = %s AND survey_questionblock.questionblock_id = %s ORDER BY survey_survey_question.sequence ASC",
                        $ilDB->quote($this->getId()),
                        $ilDB->quote($questionblock_id)
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {
                        array_push($ids, $row->question_id);
                }
                return $ids;
        }
        
        function getQuestionblock($questionblock_id)
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM survey_questionblock WHERE questionblock_id = %s",
                        $ilDB->quote($questionblock_id)
                );
                $result = $ilDB->query($query);
                $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                return $row;
        }
        
        function _getQuestionblock($questionblock_id)
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM survey_questionblock WHERE questionblock_id = %s",
                        $ilDB->quote($questionblock_id)
                );
                $result = $ilDB->query($query);
                $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                return $row;
        }

        function _addQuestionblock($title = "", $owner = 0)
        {
                global $ilDB;
                $query = sprintf("INSERT INTO survey_questionblock (questionblock_id, title, owner_fi, TIMESTAMP) VALUES (NULL, %s, %s, NULL)",
                        $ilDB->quote($title . ""),
                        $ilDB->quote($owner . "")
                );
                $result = $ilDB->query($query);
                return $ilDB->getLastInsertId();
        }
        
        function createQuestionblock($title, $show_questiontext, $questions)
        {
                global $ilDB;
                // if the selected questions are not in a continous selection, move all questions of the
                // questionblock at the position of the first selected question
                $this->moveQuestions($questions, $questions[0], 0);
                
                // now save the question block
                global $ilUser;
                $query = sprintf("INSERT INTO survey_questionblock (questionblock_id, title, show_questiontext, owner_fi, TIMESTAMP) VALUES (NULL, %s, %s, %s, NULL)",
                        $ilDB->quote($title),
                        $ilDB->quote($show_questiontext . ""),
                        $ilDB->quote($ilUser->getId())
                );
                $result = $ilDB->query($query);
                if (PEAR::isError($result)) 
                {
                        global $ilias;
                        $ilias->raiseError($result->getMessage());
                }
                else
                {
                        $questionblock_id = $ilDB->getLastInsertId();
                        foreach ($questions as $index)
                        {
                                $query = sprintf("INSERT INTO survey_questionblock_question (questionblock_question_id, survey_fi, questionblock_fi, question_fi) VALUES (NULL, %s, %s, %s)",
                                        $ilDB->quote($this->getSurveyId()),
                                        $ilDB->quote($questionblock_id),
                                        $ilDB->quote($index)
                                );
                                $result = $ilDB->query($query);
                                $this->deleteConstraints($index);
                        }
                }
        }
        
        function modifyQuestionblock($questionblock_id, $title, $show_questiontext)
        {
                global $ilDB;
                $query = sprintf("UPDATE survey_questionblock SET title = %s, show_questiontext = %s WHERE questionblock_id = %s",
                        $ilDB->quote($title),
                        $ilDB->quote($show_questiontext . ""),
                        $ilDB->quote($questionblock_id)
                );
                $result = $ilDB->query($query);
        }
        
        function deleteConstraints($question_id)
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM survey_question_constraint WHERE question_fi = %s AND survey_fi = %s",
                        $ilDB->quote($question_id),
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {
                        $query = sprintf("DELETE FROM survey_constraint WHERE constraint_id = %s",
                                $ilDB->quote($row->constraint_fi)
                        );
                        $delresult = $ilDB->query($query);
                }
                $query = sprintf("DELETE FROM survey_question_constraint WHERE question_fi = %s AND survey_fi = %s",
                        $ilDB->quote($question_id),
                        $ilDB->quote($this->getSurveyId())
                );
                $delresult = $ilDB->query($query);
        }

        function deleteConstraint($constraint_id, $question_id)
        {
                global $ilDB;
                $query = sprintf("DELETE FROM survey_constraint WHERE constraint_id = %s",
                        $ilDB->quote($constraint_id)
                );
                $delresult = $ilDB->query($query);
                $query = sprintf("DELETE FROM survey_question_constraint WHERE constraint_fi = %s AND question_fi = %s AND survey_fi = %s",
                        $ilDB->quote($constraint_id),
                        $ilDB->quote($question_id),
                        $ilDB->quote($this->getSurveyId())
                );
                $delresult = $ilDB->query($query);
        }

        function &getSurveyQuestions($with_answers = false)
        {
                global $ilDB;
                $obligatory_states =& $this->getObligatoryStates();
                // get questionblocks
                $all_questions = array();
                $query = sprintf("SELECT survey_questiontype.type_tag, survey_questiontype.plugin, survey_question.question_id, survey_survey_question.heading FROM survey_questiontype, survey_question, survey_survey_question WHERE survey_survey_question.survey_fi = %s AND survey_survey_question.question_fi = survey_question.question_id AND survey_question.questiontype_fi = survey_questiontype.questiontype_id ORDER BY survey_survey_question.sequence",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        $add = true;
                        if ($row["plugin"])
                        {
                                if (!$this->isPluginActive($row["type_tag"]))
                                {
                                        $add = false;
                                }
                        }
                        if ($add)
                        {
                                $question =& $this->_instanciateQuestion($row["question_id"]);
                                $questionrow = $question->_getQuestionDataArray($row["question_id"]);
                                foreach ($row as $key => $value)
                                {
                                        $questionrow[$key] = $value;
                                }
                                $all_questions[$row["question_id"]] = $questionrow;
                                $all_questions[$row["question_id"]]["usableForPrecondition"] = $question->usableForPrecondition();
                                $all_questions[$row["question_id"]]["availableRelations"] = $question->getAvailableRelations();
                                if (array_key_exists($row["question_id"], $obligatory_states))
                                {
                                        $all_questions[$row["question_id"]]["obligatory"] = $obligatory_states[$row["question_id"]];
                                }
                        }
                }
                // get all questionblocks
                $questionblocks = array();
                $in = join(array_keys($all_questions), "','");
                if ($in)
                {
                        $query = sprintf("SELECT survey_questionblock.*, survey_questionblock_question.question_fi FROM survey_questionblock, survey_questionblock_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_questionblock_question.survey_fi = %s AND survey_questionblock_question.question_fi IN ('$in')",
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                        {
                                $questionblocks[$row->question_fi] = $row;
                        }                       
                }
                
                foreach ($all_questions as $question_id => $row)
                {
                        $constraints = $this->getConstraints($question_id);
                        if (isset($questionblocks[$question_id]))
                        {
                                $all_questions[$question_id]["questionblock_title"] = $questionblocks[$question_id]->title;
                                $all_questions[$question_id]["questionblock_id"] = $questionblocks[$question_id]->questionblock_id;
                                $all_questions[$question_id]["constraints"] = $constraints;
                        }
                        else
                        {
                                $all_questions[$question_id]["questionblock_title"] = "";
                                $all_questions[$question_id]["questionblock_id"] = "";
                                $all_questions[$question_id]["constraints"] = $constraints;
                        }
                        if ($with_answers)
                        {
                                $answers = array();
                                $query = sprintf("SELECT survey_variable.*, survey_category.title FROM survey_variable, survey_category WHERE survey_variable.question_fi = %s AND survey_variable.category_fi = survey_category.category_id ORDER BY sequence ASC",
                                        $ilDB->quote($question_id . "")
                                );
                                $result = $ilDB->query($query);
                                if ($result->numRows() > 0) 
                                {
                                        while ($data = $result->fetchRow(MDB2_FETCHMODE_OBJECT)) 
                                        {
                                                array_push($answers, $data->title);
                                        }
                                }
                                $all_questions[$question_id]["answers"] = $answers;                             
                        }
                }
                return $all_questions;
        }
        
        function setObligatoryStates($obligatory_questions)
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM survey_survey_question WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                if (!array_key_exists($row["question_fi"], $obligatory_questions))
                                {
                                        $obligatory_questions[$row["question_fi"]] = 0;
                                }
                        }
                }

          // set the obligatory states in the database
                $query = sprintf("DELETE FROM survey_question_obligatory WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);

          // set the obligatory states in the database
                foreach ($obligatory_questions as $question_fi => $obligatory)
                {
                        $query = sprintf("INSERT INTO survey_question_obligatory (question_obligatory_id, survey_fi, question_fi, obligatory, TIMESTAMP) VALUES (NULL, %s, %s, %s, NULL)",
                                $ilDB->quote($this->getSurveyId() . ""),
                                $ilDB->quote($question_fi . ""),
                                $ilDB->quote($obligatory . "")
                        );
                        $result = $ilDB->query($query);
                }
        }
        
        function &getObligatoryStates()
        {
                global $ilDB;
                $obligatory_states = array();
                $query = sprintf("SELECT * FROM survey_question_obligatory WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                $obligatory_states[$row["question_fi"]] = $row["obligatory"];
                        }
                }
                return $obligatory_states;
        }
        
        function &getSurveyPages()
        {
                global $ilDB;
                $obligatory_states =& $this->getObligatoryStates();
                // get questionblocks
                $all_questions = array();
                $query = sprintf("SELECT survey_question.*, survey_questiontype.type_tag, survey_survey_question.heading FROM survey_question, survey_questiontype, survey_survey_question WHERE survey_survey_question.survey_fi = %s AND survey_survey_question.question_fi = survey_question.question_id AND survey_question.questiontype_fi = survey_questiontype.questiontype_id ORDER BY survey_survey_question.sequence",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        $all_questions[$row["question_id"]] = $row;
                }
                // get all questionblocks
                $questionblocks = array();
                $in = join(array_keys($all_questions), "','");
                if ($in)
                {
                        $query = sprintf("SELECT survey_questionblock.*, survey_questionblock_question.question_fi FROM survey_questionblock, survey_questionblock_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_questionblock_question.survey_fi = %s AND survey_questionblock_question.question_fi IN ('$in')",
                                $ilDB->quote($this->getSurveyId())
                        );
                        $result = $ilDB->query($query);
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                        {
                                $questionblocks["$row->question_fi"] = $row;
                        }                       
                }
                
                $all_pages = array();
                $pageindex = -1;
                $currentblock = "";
                foreach ($all_questions as $question_id => $row)
                {
                        if (array_key_exists($question_id, $obligatory_states))
                        {
                                $all_questions["$question_id"]["obligatory"] = $obligatory_states["$question_id"];
                        }
                        $constraints = array();
                        if (isset($questionblocks[$question_id]))
                        {
                                if (!$currentblock or ($currentblock != $questionblocks[$question_id]->questionblock_id))
                                {
                                        $pageindex++;
                                }
                                $all_questions[$question_id]["questionblock_title"] = $questionblocks[$question_id]->title;
                                $all_questions[$question_id]["questionblock_id"] = $questionblocks[$question_id]->questionblock_id;
                                $all_questions[$question_id]["questionblock_show_questiontext"] = $questionblocks[$question_id]->show_questiontext;
                                $currentblock = $questionblocks[$question_id]->questionblock_id;
                                $constraints = $this->getConstraints($question_id);
                                $all_questions[$question_id]["constraints"] = $constraints;
                        }
                        else
                        {
                                $pageindex++;
                                $all_questions[$question_id]["questionblock_title"] = "";
                                $all_questions[$question_id]["questionblock_id"] = "";
                                $all_questions[$question_id]["questionblock_show_questiontext"] = 1;
                                $currentblock = "";
                                $constraints = $this->getConstraints($question_id);
                                $all_questions[$question_id]["constraints"] = $constraints;
                        }
                        if (!isset($all_pages[$pageindex]))
                        {
                                $all_pages[$pageindex] = array();
                        }
                        array_push($all_pages[$pageindex], $all_questions[$question_id]);
                }
                // calculate position percentage for every page
                $max = count($all_pages);
                $counter = 1;
                foreach ($all_pages as $index => $block)
                {
                        foreach ($block as $blockindex => $question)
                        {
                                $all_pages[$index][$blockindex][position] = $counter / $max;
                        }
                        $counter++;
                }
                return $all_pages;
        }
        
        function getNextPage($active_page_question_id, $direction)
        {
                $foundpage = -1;
                $pages =& $this->getSurveyPages();
                if (strcmp($active_page_question_id, "") == 0)
                {
                        return $pages[0];
                }
                
                foreach ($pages as $key => $question_array)
                {
                        foreach ($question_array as $question)
                        {
                                if ($active_page_question_id == $question["question_id"])
                                {
                                        $foundpage = $key;
                                }
                        }
                }
                if ($foundpage == -1)
                {
                        // error: page not found
                }
                else
                {
                        $foundpage += $direction;
                        if ($foundpage < 0)
                        {
                                return 0;
                        }
                        if ($foundpage >= count($pages))
                        {
                                return 1;
                        }
                        return $pages[$foundpage];
                }
        }
                
        function &getAvailableQuestionpools($use_obj_id = false, $could_be_offline = false, $showPath = FALSE, $permission = "read")
        {
                include_once "./Modules/SurveyQuestionPool/classes/class.ilObjSurveyQuestionPool.php";
                return ilObjSurveyQuestionPool::_getAvailableQuestionpools($use_obj_id, $could_be_offline, $showPath, $permission);
        }
        
        function getPrecondition($id)
        {
                global $ilDB;
                
                $result_array = array();
                $query = sprintf("SELECT survey_constraint.*, survey_relation.* FROM survey_question_constraint, survey_constraint, survey_relation WHERE survey_constraint.relation_fi = survey_relation.relation_id AND survey_question_constraint.constraint_fi = survey_constraint.constraint_id AND survey_constraint.constraint_id = %s",
                        $ilDB->quote($id . "")
                );
                $result = $ilDB->query($query);
                $pc = array();
                if ($result->numRows())
                {
                        $pc = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                }
                return $pc;
        }
        
        function getConstraints($question_id)
        {
                global $ilDB;
                
                $result_array = array();
                $query = sprintf("SELECT survey_constraint.*, survey_relation.* FROM survey_question_constraint, survey_constraint, survey_relation WHERE survey_constraint.relation_fi = survey_relation.relation_id AND survey_question_constraint.constraint_fi = survey_constraint.constraint_id AND survey_question_constraint.question_fi = %s AND survey_question_constraint.survey_fi = %s",
                        $ilDB->quote($question_id),
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {       
                        include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                        $question_type = SurveyQuestion::_getQuestionType($row->question_fi);
                        SurveyQuestion::_includeClass($question_type);
                        $question = new $question_type();
                        $question->loadFromDb($row->question_fi);
                        $valueoutput = $question->getPreconditionValueOutput($row->value);
                        array_push($result_array, array("id" => $row->constraint_id, "question" => $row->question_fi, "short" => $row->shortname, "long" => $row->longname, "value" => $row->value, "valueoutput" => $valueoutput));
                }
                return $result_array;
        }

        function _getConstraints($survey_id)
        {
                global $ilDB;
                $result_array = array();
                $query = sprintf("SELECT survey_question_constraint.question_fi as for_question, survey_constraint.*, survey_relation.* FROM survey_question_constraint, survey_constraint, survey_relation WHERE survey_constraint.relation_fi = survey_relation.relation_id AND survey_question_constraint.constraint_fi = survey_constraint.constraint_id AND survey_question_constraint.survey_fi = %s",
                        $ilDB->quote($survey_id . "")
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {               
                        array_push($result_array, array("id" => $row->constraint_id, "for_question" => $row->for_question, "question" => $row->question_fi, "short" => $row->shortname, "long" => $row->longname, "relation_id" => $row->relation_id, "value" => $row->value));
                }
                return $result_array;
        }


        function &getVariables($question_id)
        {
                global $ilDB;
                
                $result_array = array();
                $query = sprintf("SELECT survey_variable.*, survey_category.title FROM survey_variable LEFT JOIN survey_category ON survey_variable.category_fi = survey_category.category_id WHERE survey_variable.question_fi = %s ORDER BY survey_variable.sequence",
                        $ilDB->quote($question_id)
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {
                        $result_array[$row->sequence] = $row;
                }
                return $result_array;
        }
        
        function addConstraint($to_question_id, $if_question_id, $relation, $value)
        {
                global $ilDB;
                
                $query = sprintf("INSERT INTO survey_constraint (constraint_id, question_fi, relation_fi, value) VALUES (NULL, %s, %s, %s)",
                        $ilDB->quote($if_question_id),
                        $ilDB->quote($relation),
                        $ilDB->quote($value)
                );
                $result = $ilDB->query($query);
                if (PEAR::isError($result)) 
                {
                        global $ilias;
                        $ilias->raiseError($result->getMessage());
                }
                else
                {
                        $constraint_id = $ilDB->getLastInsertId();
                        $query = sprintf("INSERT INTO survey_question_constraint (question_constraint_id, survey_fi, question_fi, constraint_fi) VALUES (NULL, %s, %s, %s)",
                                $ilDB->quote($this->getSurveyId()),
                                $ilDB->quote($to_question_id),
                                $ilDB->quote($constraint_id)
                        );
                        $result = $ilDB->query($query);
                }
        }
        
                function updateConstraint($to_question_id, $if_question_id, $relation, $value)
                {
                        global $ilDB;
                        $query = sprintf("SELECT constraint_fi FROM survey_question_constraint WHERE question_fi = %s AND survey_fi = %s",
                                $ilDB->quote($to_question_id . ""),
                                $ilDB->quote($this->getSurveyId() . "")
                        );
                        $result = $ilDB->query($query);
                        if ($result->numRows())
                        {
                                $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                                $query = sprintf("UPDATE survey_constraint SET question_fi = %s, relation_fi = %s, value = %s WHERE constraint_id = %s",
                                        $ilDB->quote($if_question_id),
                                        $ilDB->quote($relation),
                                        $ilDB->quote($value),
                                        $ilDB->quote($row["constraint_fi"])
                                );
                                $result = $ilDB->query($query);
                        }
                }

        function getAllRelations($short_as_key = false)
        {
                global $ilDB;
                
                $result_array = array();
                $query = "SELECT * FROM survey_relation";
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {
                        if ($short_as_key)
                        {
                                $result_array[$row->shortname] = array("short" => $row->shortname, "long" => $row->longname, "id" => $row->relation_id);
                        }
                        else
                        {
                                $result_array[$row->relation_id] = array("short" => $row->shortname, "long" => $row->longname);
                        }
                }
                return $result_array;
        }

        function disinviteUser($user_id)
        {
                global $ilDB;
                
                $query = sprintf("DELETE FROM survey_invited_user WHERE survey_fi = %s AND user_fi = %s",
                        $ilDB->quote($this->getSurveyId()),
                        $ilDB->quote($user_id)
                );
                $result = $ilDB->query($query);
                if ($this->getInvitation() == INVITATION_ON)
                {
                        include_once './Services/User/classes/class.ilObjUser.php';
                        if (ilObjUser::_lookupLogin($user_id))
                        {
                                $userObj = new ilObjUser($user_id);
                                $userObj->dropDesktopItem($this->getRefId(), "svy");
                        }
                }
        }

        function inviteUser($user_id)
        {
                global $ilDB;
                
                $query = sprintf("SELECT user_fi FROM survey_invited_user WHERE user_fi = %s AND survey_fi = %s",
                        $ilDB->quote($user_id),
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                if ($result->numRows() < 1)
                {
                        $query = sprintf("INSERT INTO survey_invited_user (invited_user_id, survey_fi, user_fi, TIMESTAMP) VALUES (NULL, %s, %s, NULL)",
                                $ilDB->quote($this->getSurveyId()),
                                $ilDB->quote($user_id)
                        );
                        $result = $ilDB->query($query);
                }
                if ($this->getInvitation() == INVITATION_ON)
                {
                        include_once './Services/User/classes/class.ilObjUser.php';
                        if (ilObjUser::_lookupLogin($user_id))
                        {
                                $userObj = new ilObjUser($user_id);
                                $userObj->addDesktopItem($this->getRefId(), "svy");
                        }
                }
        }

                function inviteGroup($group_id)
                {
                        global $ilAccess;
                        $invited = 0;
                        include_once "./Modules/Group/classes/class.ilObjGroup.php";
                        $group = new ilObjGroup($group_id);
                        $members = $group->getGroupMemberIds();
                        foreach ($members as $user_id)
                        {
                                if ($ilAccess->checkAccessOfUser($user_id, "read", "", $this->getRefId(), "svy", $this->getId()))
                                {
                                        $this->inviteUser($user_id);
                                        if ($this->getInvitation() == INVITATION_ON)
                                        {
                                                if (ilObjUser::_lookupLogin($user_id))
                                                {
                                                        $userObj = new ilObjUser($user_id);
                                                        $userObj->addDesktopItem($this->getRefId(), "svy");
                                                        $invited++;
                                                }
                                        }
                                }
                        }
                        return $invited;
                }

                function inviteRole($role_id)
                {
                        global $rbacreview;
                        global $ilAccess;
                        $invited = 0;
                        $members = $rbacreview->assignedUsers($role_id);
                        foreach ($members as $user_id)
                        {
                                if ($ilAccess->checkAccessOfUser($user_id, "read", "", $this->getRefId(), "svy", $this->getId()))
                                {
                                        $this->inviteUser($user_id);
                                        if ($this->getInvitation() == INVITATION_ON)
                                        {
                                                if (ilObjUser::_lookupLogin($user_id))
                                                {
                                                        $userObj = new ilObjUser($user_id);
                                                        $userObj->addDesktopItem($this->getRefId(), "svy");
                                                        $invited++;
                                                }
                                        }
                                }
                        }
                        return $invited;
                }

        function &getInvitedUsers()
        {
                global $ilDB;
                
                $result_array = array();
                $query = sprintf("SELECT user_fi FROM survey_invited_user WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {
                        array_push($result_array, $row->user_fi);
                }
                return $result_array;
        }

        function &getInvitedGroups()
        {
                global $ilDB;
                
                $result_array = array();
                $query = sprintf("SELECT group_fi FROM survey_invited_group WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_OBJECT))
                {
                        array_push($result_array, $row->group_fi);
                }
                return $result_array;
        }

        function deleteWorkingData($question_id, $active_id)
        {
                global $ilDB;
                
                $query = "";
                $query = sprintf("DELETE FROM survey_answer WHERE question_fi = %s AND active_fi = %s",
                        $ilDB->quote($question_id),
                        $ilDB->quote($active_id)
                );
                $result = $ilDB->query($query);
        }
        
        function loadWorkingData($question_id, $active_id)
        {
                global $ilDB;
                $result_array = array();
                $query = sprintf("SELECT * FROM survey_answer WHERE question_fi = %s AND active_fi = %s",
                        $ilDB->quote($question_id. ""),
                        $ilDB->quote($active_id)
                );
                $result = $ilDB->query($query);
                if ($result->numRows() >= 1)
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                array_push($result_array, $row);
                        }
                        return $result_array;
                }
                else
                {
                        return $result_array;
                }
        }
        
        function fillSurveyForUser($user_id = ANONYMOUS_USER_ID)
        {
                global $ilDB;
                // create an anonymous key
                $anonymous_id = $this->createNewAccessCode();
                $this->saveUserAccessCode($user_id, $anonymous_id);
                // create the survey_finished dataset and set the survey finished already
                $query = sprintf("INSERT INTO survey_finished (finished_id, survey_fi, user_fi, anonymous_id, state, TIMESTAMP) VALUES (NULL, %s, %s, %s, %s, NULL)",
                        $ilDB->quote($this->getSurveyId() . ""),
                        $ilDB->quote($user_id . ""),
                        $ilDB->quote($anonymous_id . ""),
                        $ilDB->quote(1 . "")
                );
                $result = $ilDB->query($query);
                // get the active id for the user
                $active_id = $ilDB->getLastInsertId();
                // fill the questions randomly
                $pages =& $this->getSurveyPages();
                foreach ($pages as $key => $question_array)
                {
                        foreach ($question_array as $question)
                        {
                                // instanciate question
                                require_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                                $question =& SurveyQuestion::_instanciateQuestion($question["question_id"]);
                                $question->saveRandomData($active_id);
                        }
                }               
        }

        function startSurvey($user_id, $anonymous_id)
        {
                global $ilUser;
                global $ilDB;
                
                if ($this->getAnonymize() && (strlen($anonymous_id) == 0)) return;

                if (strcmp($user_id, "") == 0)
                {
                        if ($user_id == ANONYMOUS_USER_ID)
                        {
                                $user_id = 0;
                        }
                }
                $query = sprintf("INSERT INTO survey_finished (finished_id, survey_fi, user_fi, anonymous_id, state, TIMESTAMP) VALUES (NULL, %s, %s, %s, %s, NULL)",
                        $ilDB->quote($this->getSurveyId() . ""),
                        $ilDB->quote($user_id . ""),
                        $ilDB->quote($anonymous_id . ""),
                        $ilDB->quote(0 . "")
                );
                $result = $ilDB->query($query);
                
                // get the insert id, but don't trust last_insert_id since we don't have transactions
                $query = sprintf("SELECT finished_id FROM survey_finished WHERE survey_fi = %s AND user_fi = %s AND anonymous_id = %s",
                        $ilDB->quote($this->getSurveyId() . ""),
                        $ilDB->quote($user_id . ""),
                        $ilDB->quote($anonymous_id . "")
                );
                $result = $ilDB->query($query);
                $insert_id = 0;
                if ($result->numRows())
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        $insert_id = $row["finished_id"];
                }
                return $insert_id;
        }
                        
        function finishSurvey($user_id, $anonymize_id)
        {
                global $ilDB;
                
                if ($this->getAnonymize())
                {
                        $query = sprintf("UPDATE survey_finished SET state = %s, user_fi = %s WHERE survey_fi = %s AND anonymous_id = %s",
                                $ilDB->quote("1"),
                                $ilDB->quote($user_id . ""),
                                $ilDB->quote($this->getSurveyId() . ""),
                                $ilDB->quote($anonymize_id . "")
                        );
                }
                else
                {
                        $query = sprintf("UPDATE survey_finished SET state = %s WHERE survey_fi = %s AND user_fi = %s",
                                $ilDB->quote("1"),
                                $ilDB->quote($this->getSurveyId() . ""),
                                $ilDB->quote($user_id . "")
                        );
                }
                $result = $ilDB->query($query);
        }
        
        function isAllowedToTakeMultipleSurveys($userid = "")
        {
                $result = FALSE;
                if ($this->getAnonymize())
                {
                        if ($this->isAccessibleWithoutCode())
                        {
                                if (strlen($username) == 0)
                                {
                                        global $ilUser;
                                        $userid = $ilUser->getId();
                                }
                                global $ilSetting;
                                $surveysetting = new ilSetting("survey");
                                $allowedUsers = strlen($surveysetting->get("multiple_survey_users")) ? explode(",",$surveysetting->get("multiple_survey_users")) : array();
                                if (in_array($userid, $allowedUsers))
                                {
                                        $result = TRUE;
                                }
                        }
                }
                return $result;
        }
        
        function isSurveyStarted($user_id, $anonymize_id)
        {
                global $ilDB;

                if ($this->getAnonymize())
                {
                        if ((($user_id != ANONYMOUS_USER_ID) && (strlen($anonymize_id) == 0)) && (!($this->isAccessibleWithoutCode() && $this->isAllowedToTakeMultipleSurveys())))
                        {
                                $query = sprintf("SELECT * FROM survey_finished WHERE survey_fi = %s AND user_fi = %s",
                                        $ilDB->quote($this->getSurveyId()),
                                        $ilDB->quote($user_id)
                                );
                        }
                        else
                        {
                                $query = sprintf("SELECT * FROM survey_finished WHERE survey_fi = %s AND anonymous_id = %s",
                                        $ilDB->quote($this->getSurveyId()),
                                        $ilDB->quote($anonymize_id)
                                );
                        }
                }
                else
                {
                        $query = sprintf("SELECT * FROM survey_finished WHERE survey_fi = %s AND user_fi = %s",
                                $ilDB->quote($this->getSurveyId()),
                                $ilDB->quote($user_id)
                        );
                }
                $result = $ilDB->query($query);
                if ($result->numRows() == 0)
                {
                        return false;
                }                       
                else
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        $_SESSION["finished_id"] = $row["finished_id"];
                        return (int)$row["state"];
                }
        }
        
        function getLastActivePage($active_id)
        {
                global $ilDB;
                $query = sprintf("SELECT question_fi, TIMESTAMP + 0 AS timestamp14 FROM survey_answer WHERE active_fi = %s ORDER BY timestamp14 DESC",
                        $ilDB->quote($active_id)
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 0)
                {
                        return "";
                }
                else
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        return $row["question_fi"];
                }
        }

        function checkConstraint($constraint_data, $working_data)
        {
                if (count($working_data) == 0)
                {
                        return 0;
                }
                
                if ((count($working_data) == 1) and (strcmp($working_data[0]["value"], "") == 0))
                {
                        return 0;
                }
                
                foreach ($working_data as $data)
                {
                        switch ($constraint_data["short"])
                        {
                                case "<":
                                        if ($data["value"] < $constraint_data["value"])
                                        {
                                                return 1;
                                        }
                                        break;
                                case "<=":
                                        if ($data["value"] <= $constraint_data["value"])
                                        {
                                                return 1;
                                        }
                                        break;
                                case "=":
                                        if ($data["value"] == $constraint_data["value"])
                                        {
                                                return 1;
                                        }
                                        break;
                                case "<>":
                                        if ($data["value"] != $constraint_data["value"])
                                        {
                                                return 1;
                                        }
                                        break;
                                case ">=":
                                        if ($data["value"] >= $constraint_data["value"])
                                        {
                                                return 1;
                                        }
                                        break;
                                case ">":
                                        if ($data["value"] > $constraint_data["value"])
                                        {
                                                return 1;
                                        }
                                        break;
                        }
                }
                return 0;
        }
        
        function _hasDatasets($survey_id)
        {
                global $ilDB;
                
                $query = sprintf("SELECT finished_id FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($survey_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        return true;
                }
                else
                {
                        return false;
                }
        }

        function &getSurveyFinishedIds()
        {
                global $ilDB, $ilLog;
                
                $users = array();
                $query = sprintf("SELECT * FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                array_push($users, $row["finished_id"]);
                        }
                }
                return $users;
        }
        
        function &getUserSpecificResults()
        {
                global $ilDB;
                
                $users = array();
                $query = sprintf("SELECT * FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                array_push($users, $row);
                        }
                }
                $evaluation = array();
                $questions =& $this->getSurveyQuestions();
                foreach ($questions as $question_id => $question_data)
                {
                        include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                        $question_type = SurveyQuestion::_getQuestionType($question_id);
                        SurveyQuestion::_includeClass($question_type);
                        $question = new $question_type();
                        $question->loadFromDb($question_id);
                        $data =& $question->getUserAnswers($this->getSurveyId());
                        $evaluation[$question_id] = $data;
                }
                return $evaluation;
        }
        
        function getUserDataFromActiveId($active_id)
        {
                global $ilDB;
                
                $query = sprintf("SELECT * FROM survey_finished WHERE finished_id = %s",
                        $ilDB->quote($active_id)
                );
                $result = $ilDB->query($query);
                $surveySetting = new ilSetting("survey");
                $use_anonymous_id = array_key_exists("use_anonymous_id", $_GET) ? $_GET["use_anonymous_id"] : $surveySetting->get("use_anonymous_id");
                $row = array();
                $foundrows = $result->numRows();
                if ($foundrows)
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                }
                $name = ($use_anonymous_id) ? $row["anonymous_id"] : $this->lng->txt("anonymous");
                $userdata = array(
                        "fullname" => $name,
                        "sortname" => $name,
                        "firstname" => "",
                        "lastname" => "",
                        "login" => "",
                        "gender" => "",
                        "active_id" => "$active_id"
                );
                if ($foundrows)
                {
                        if (($row["user_fi"] > 0) && ($row["user_fi"] != ANONYMOUS_USER_ID) && ($this->getAnonymize() == 0))
                        {
                                include_once './Services/User/classes/class.ilObjUser.php';
                                if (strlen(ilObjUser::_lookupLogin($row["user_fi"])) == 0)
                                {
                                        $userdata["fullname"] = $this->lng->txt("deleted_user");
                                }
                                else
                                {
                                        $user = new ilObjUser($row["user_fi"]);
                                        $userdata["fullname"] = $user->getFullname();
                                        $gender = $user->getGender();
                                        if (strlen($gender) == 1) $gender = $this->lng->txt("gender_$gender");
                                        $userdata["gender"] = $gender;
                                        $userdata["firstname"] = $user->getFirstname();
                                        $userdata["lastname"] = $user->getLastname();
                                        $userdata["sortname"] = $user->getLastname() . ", " . $user->getFirstname();
                                        $userdata["login"] = $user->getLogin();
                                }
                        }
                }
                return $userdata;
        }
        
        function &getEvaluationByUser($questions, $active_id)
        {
                global $ilDB;
                
                // collect all answers
                $answers = array();
                $query = sprintf("SELECT * FROM survey_answer WHERE active_fi = %s",
                        $ilDB->quote($active_id)
                );
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        if (!is_array($answers[$row["question_fi"]]))
                        {
                                $answers[$row["question_fi"]] = array();
                        }
                        array_push($answers[$row["question_fi"]], $row);
                }
                $userdata = $this->getUserDataFromActiveId($active_id);
                $resultset = array(
                        "name" => $userdata["fullname"],
                        "gender" => $userdata["gender"],
                        "answers" => array()
                );
                foreach ($questions as $key => $question)
                {
                        if (array_key_exists($key, $answers))
                        {
                                $resultset["answers"][$key] = $answers[$key];
                        }
                        else
                        {
                                $resultset["answers"][$key] = array();
                        }
                        sort($resultset["answers"][$key]);
                }
                return $resultset;
        }
        
        function getCumulatedResults(&$question)
        {
                global $ilDB;
                
                $query = sprintf("SELECT finished_id FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId())
                );
                $result = $ilDB->query($query);
                $nr_of_users = $result->numRows();
                
                $result_array =& $question->getCumulatedResults($this->getSurveyId(), $nr_of_users);
                return $result_array;
        }

        function _getNrOfParticipants($survey_id)
        {
                global $ilDB;
                
                $query = sprintf("SELECT finished_id FROM survey_finished WHERE survey_fi = %s",
                        $ilDB->quote($survey_id . "")
                );
                $result = $ilDB->query($query);
                return $result->numRows();
        }

        function &getQuestions($question_ids)
        {
                $result_array = array();
                $query = "SELECT survey_question.*, survey_questiontype.type_tag FROM survey_question, survey_questiontype WHERE survey_question.questiontype_fi = survey_questiontype.questiontype_id AND survey_question.question_id IN ('" . join($question_ids, "','") . "')";
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        array_push($result_array, $row);
                }
                return $result_array;
        }
        
        function &getQuestionblocks($questionblock_ids)
        {
                global $ilDB;
                
                $result_array = array();
    $query = "SELECT survey_questionblock.*, survey_survey.obj_fi, survey_question.title AS questiontitle, survey_survey_question.sequence, object_data.title as surveytitle, survey_question.question_id FROM object_reference, object_data, survey_questionblock, survey_questionblock_question, survey_survey, survey_question, survey_survey_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_survey.survey_id = survey_questionblock_question.survey_fi AND survey_questionblock_question.question_fi = survey_question.question_id AND survey_survey.obj_fi = object_reference.obj_id AND object_reference.obj_id = object_data.obj_id AND survey_survey_question.survey_fi = survey_survey.survey_id AND survey_survey_question.question_fi = survey_question.question_id AND survey_questionblock.questionblock_id IN ('" . join($questionblock_ids, "','") . "') ORDER BY survey_survey.survey_id, survey_survey_question.sequence";
                $result = $ilDB->query($query);
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        if ($row["questionblock_id"] != $qbid)
                        {
                                $sequence = 1;
                        }
                        $row["sequence"] = $sequence++;
                        $result_array[$row["questionblock_id"]][$row["question_id"]] = $row;
                        $qbid = $row["questionblock_id"];
                }
                return $result_array;
        }

        function getQuestionsTable($sort, $sortorder, $filter_text, $sel_filter_type, $startrow = 0, $completeonly = 0, $filter_question_type = "", $filter_questionpool = "")
        {
                global $ilUser;
                global $ilDB;
                
                $where = "";
                if (strlen($filter_text) > 0) 
                {
                        switch($sel_filter_type) 
                        {
                                case "title":
                                        $where = " AND survey_question.title LIKE " . $ilDB->quote("%" . $filter_text . "%");
                                        break;
                                case "description":
                                        $where = " AND survey_question.description LIKE " . $ilDB->quote("%" . $filter_text . "%");
                                        break;
                                case "author":
                                        $where = " AND survey_question.author LIKE " . $ilDB->quote("%" . $filter_text . "%");
                                        break;
                        }
                }
  
                if ($filter_question_type && (strcmp($filter_question_type, "all") != 0))
                {
                        $where .= " AND survey_questiontype.type_tag = " . $ilDB->quote($filter_question_type);
                }
                
                if ($filter_questionpool && (strcmp($filter_questionpool, "all") != 0))
                {
                        $where .= " AND survey_question.obj_fi = $filter_questionpool";
                }
  
    // build sort order for sql query
                $order = "";
                $images = array();
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                switch($sort) 
                {
                        case "title":
                                $order = " ORDER BY title $sortorder";
                                $images["title"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                        case "description":
                                $order = " ORDER BY description $sortorder";
                                $images["description"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                        case "type":
                                $order = " ORDER BY questiontype_id $sortorder";
                                $images["type"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                        case "author":
                                $order = " ORDER BY author $sortorder";
                                $images["author"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                        case "created":
                                $order = " ORDER BY created $sortorder";
                                $images["created"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                        case "updated":
                                $order = " ORDER BY timestamp14 $sortorder";
                                $images["updated"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                        case "qpl":
                                $order = " ORDER BY obj_fi $sortorder";
                                $images["qpl"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                }
                $maxentries = $ilUser->prefs["hits_per_page"];
                if ($maxentries < 1)
                {
                        $maxentries = 9999;
                }

                $spls =& $this->getAvailableQuestionpools($use_obj_id = TRUE, $could_be_offline = FALSE, $showPath = FALSE);
                $forbidden = "";
                $forbidden = " AND survey_question.obj_fi IN ('" . join(array_keys($spls), "','") . "')";
                if ($completeonly)
                {
                        $forbidden .= " AND survey_question.complete = " . $ilDB->quote("1");
                }
                $existing = "";
                $existing_questions =& $this->getExistingQuestions();
                if (count($existing_questions))
                {
                        $existing = " AND survey_question.question_id NOT IN ('" . join($existing_questions, "','") . "')";
                }
                $limit = " LIMIT $startrow, $maxentries";
                $query = "SELECT survey_question.*, survey_question.TIMESTAMP + 0 AS timestamp14, survey_questiontype.type_tag, survey_questiontype.plugin, object_reference.ref_id FROM survey_question, survey_questiontype, object_reference WHERE survey_question.questiontype_fi = survey_questiontype.questiontype_id$forbidden$existing AND survey_question.obj_fi = object_reference.obj_id AND ISNULL(survey_question.original_id) " . " $where$order";
                $query_result = $ilDB->query($query);
                $max = $query_result->numRows();
                $query = "SELECT survey_question.*, survey_question.TIMESTAMP + 0 AS timestamp14, survey_questiontype.type_tag, survey_questiontype.plugin, object_reference.ref_id FROM survey_question, survey_questiontype, object_reference WHERE survey_question.questiontype_fi = survey_questiontype.questiontype_id$forbidden$existing AND survey_question.obj_fi = object_reference.obj_id AND ISNULL(survey_question.original_id) " . " $where$order$limit";
                $query_result = $ilDB->query($query);
                if ($startrow > $max -1)
                {
                        $startrow = $max - ($max % $maxentries);
                }
                else if ($startrow < 0)
                {
                        $startrow = 0;
                }
                $rows = array();
                if ($query_result->numRows())
                {
                        while ($row = $query_result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                if ($row["plugin"])
                                {
                                        if ($this->isPluginActive($row["type_tag"]))
                                        {
                                                array_push($rows, $row);
                                        }
                                }
                                else
                                {
                                        array_push($rows, $row);
                                }
                        }
                }
                $nextrow = $startrow + $maxentries;
                if ($nextrow > $max - 1)
                {
                        $nextrow = $startrow;
                }
                $prevrow = $startrow - $maxentries;
                if ($prevrow < 0)
                {
                        $prevrow = 0;
                }
                return array(
                        "rows" => $rows,
                        "images" => $images,
                        "startrow" => $startrow,
                        "nextrow" => $nextrow,
                        "prevrow" => $prevrow,
                        "step" => $maxentries,
                        "rowcount" => $max
                );
        }

        function getQuestionblocksTable($sort, $sortorder, $filter_text, $sel_filter_type, $startrow = 0)
        {
                global $ilDB;
                global $ilUser;
                $where = "";
                if (strlen($filter_text) > 0) {
                        switch($sel_filter_type) {
                                case "title":
                                        $where = " AND survey_questionblock.title LIKE " . $ilDB->quote("%" . $filter_text . "%");
                                        break;
                        }
                }
  
    // build sort order for sql query
                $order = "";
                $images = array();
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                switch($sort) 
                {
                        case "title":
                                $order = " ORDER BY survey_questionblock.title $sortorder";
                                $images["title"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                        case "svy":
                                $order = " ORDER BY survey_survey_question.survey_fi $sortorder";
                                $images["svy"] = " <img src=\"" . ilUtil::getImagePath(strtolower($sortorder) . "_order.gif") . "\" alt=\"" . strtolower($sortorder) . "ending order\" />";
                                break;
                }
                $maxentries = $ilUser->prefs["hits_per_page"];
                if ($order)
                {
                        $order .=  ",survey_survey_question.sequence ASC";
                }
                else
                {
                        $order = " ORDER BY survey_survey_question.sequence ASC";
                }
                $query = "SELECT survey_questionblock.questionblock_id FROM object_reference, object_data, survey_questionblock, survey_questionblock_question, survey_survey, survey_question, survey_survey_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_survey.survey_id = survey_questionblock_question.survey_fi AND survey_questionblock_question.question_fi = survey_question.question_id AND survey_survey.obj_fi = object_reference.obj_id AND object_reference.obj_id = object_data.obj_id AND survey_survey_question.survey_fi = survey_survey.survey_id AND survey_survey_question.question_fi = survey_question.question_id$where GROUP BY survey_questionblock.questionblock_id$order$limit";
    $query_result = $ilDB->query($query);
                $questionblock_ids = array();
                if ($query_result->numRows())
                {
                        while ($row = $query_result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                array_push($questionblock_ids, $row["questionblock_id"]);
                        }
                }
                
                $max = $query_result->numRows();
                if ($startrow > $max -1)
                {
                        $startrow = $max - ($max % $maxentries);
                }
                else if ($startrow < 0)
                {
                        $startrow = 0;
                }
                $limit = " LIMIT $startrow, $maxentries";
                $query = "SELECT survey_questionblock.*, object_data.title as surveytitle FROM object_reference, object_data, survey_questionblock, survey_questionblock_question, survey_survey, survey_question, survey_survey_question WHERE survey_questionblock.questionblock_id = survey_questionblock_question.questionblock_fi AND survey_survey.survey_id = survey_questionblock_question.survey_fi AND survey_questionblock_question.question_fi = survey_question.question_id AND survey_survey.obj_fi = object_reference.obj_id AND object_reference.obj_id = object_data.obj_id AND survey_survey_question.survey_fi = survey_survey.survey_id AND survey_survey_question.question_fi = survey_question.question_id$where GROUP BY survey_questionblock.questionblock_id$order$limit";
    $query_result = $ilDB->query($query);
                $rows = array();
                if ($query_result->numRows())
                {
                        while ($row = $query_result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                $questions_array =& $this->getQuestionblockQuestions($row["questionblock_id"]);
                                $counter = 1;
                                foreach ($questions_array as $key => $value)
                                {
                                        $questions_array[$key] = "$counter. $value";
                                        $counter++;
                                }
                                $rows[$row["questionblock_id"]] = array(
                                        "questionblock_id" => $row["questionblock_id"],
                                        "title" => $row["title"], 
                                        "surveytitle" => $row["surveytitle"], 
                                        "questions" => join($questions_array, ", "),
                                        "owner" => $row["owner_fi"]
                                );
                        }
                }
                $nextrow = $startrow + $maxentries;
                if ($nextrow > $max - 1)
                {
                        $nextrow = $startrow;
                }
                $prevrow = $startrow - $maxentries;
                if ($prevrow < 0)
                {
                        $prevrow = 0;
                }
                return array(
                        "rows" => $rows,
                        "images" => $images,
                        "startrow" => $startrow,
                        "nextrow" => $nextrow,
                        "prevrow" => $prevrow,
                        "step" => $maxentries,
                        "rowcount" => $max
                );
        }

        function toXML()
        {
                include_once("./classes/class.ilXmlWriter.php");
                $a_xml_writer = new ilXmlWriter;
                // set xml header
                $a_xml_writer->xmlHeader();
                $attrs = array(
                        "xmlns:xsi" => "http://www.w3.org/2001/XMLSchema-instance",
                        "xsi:noNamespaceSchemaLocation" => "http://www.ilias.de/download/xsd/ilias_survey_3_8.xsd"
                );
                $a_xml_writer->xmlStartTag("surveyobject", $attrs);
                $attrs = array(
                        "id" => $this->getSurveyId(),
                        "title" => $this->getTitle()
                );
                $a_xml_writer->xmlStartTag("survey", $attrs);
                
                $a_xml_writer->xmlElement("description", NULL, $this->getDescription());
                $a_xml_writer->xmlElement("author", NULL, $this->getAuthor());
                $a_xml_writer->xmlStartTag("objectives");
                $attrs = array(
                        "label" => "introduction"
                );
                $this->addMaterialTag($a_xml_writer, $this->getIntroduction(), TRUE, TRUE, $attrs);
                $attrs = array(
                        "label" => "outro"
                );
                $this->addMaterialTag($a_xml_writer, $this->getOutro(), TRUE, TRUE, $attrs);
                $a_xml_writer->xmlEndTag("objectives");

                if ($this->getAnonymize())
                {
                        $attribs = array("enabled" => "1");
                }
                else
                {
                        $attribs = array("enabled" => "0");
                }
                $a_xml_writer->xmlElement("anonymisation", $attribs);
                $a_xml_writer->xmlStartTag("restrictions");
                if ($this->getAnonymize() == 2)
                {
                        $attribs = array("type" => "free");
                }
                else
                {
                        $attribs = array("type" => "restricted");
                }
                $a_xml_writer->xmlElement("access", $attribs);
                if ($this->getStartDateEnabled())
                {
                        $attrs = array("type" => "date");
                        $a_xml_writer->xmlElement("startingtime", $attrs, sprintf("%04d-%02d-%02dT00:00:00", $this->getStartYear(), $this->getStartMonth(), $this->getStartDay()));
                }
                if ($this->getEndDateEnabled())
                {
                        $attrs = array("type" => "date");
                        $a_xml_writer->xmlElement("endingtime", $attrs, sprintf("%04d-%02d-%02dT00:00:00", $this->getEndYear(), $this->getEndMonth(), $this->getEndDay()));
                }
                $a_xml_writer->xmlEndTag("restrictions");
                
                // constraints
                $pages =& $this->getSurveyPages();
                $hasconstraints = FALSE;
                foreach ($pages as $question_array)
                {
                        foreach ($question_array as $question)
                        {
                                if (count($question["constraints"]))
                                {
                                        $hasconstraints = TRUE;
                                }
                        }
                }
                
                if ($hasconstraints)
                {
                        $a_xml_writer->xmlStartTag("constraints");
                        foreach ($pages as $question_array)
                        {
                                foreach ($question_array as $question)
                                {
                                        if (count($question["constraints"]))
                                        {
                                                // found constraints
                                                foreach ($question["constraints"] as $constraint)
                                                {
                                                        $attribs = array(
                                                                "sourceref" => $question["question_id"],
                                                                "destref" => $constraint["question"],
                                                                "relation" => $constraint["short"],
                                                                "value" => $constraint["value"]
                                                        );
                                                        $a_xml_writer->xmlElement("constraint", $attribs);
                                                }
                                        }
                                }
                        }
                        $a_xml_writer->xmlEndTag("constraints");
                }
                
                // add the rest of the preferences in qtimetadata tags, because there is no correspondent definition in QTI
                $a_xml_writer->xmlStartTag("metadata");

                $a_xml_writer->xmlStartTag("metadatafield");
                $a_xml_writer->xmlElement("fieldlabel", NULL, "evaluation_access");
                $a_xml_writer->xmlElement("fieldentry", NULL, $this->getEvaluationAccess());
                $a_xml_writer->xmlEndTag("metadatafield");

                $a_xml_writer->xmlStartTag("metadatafield");
                $a_xml_writer->xmlElement("fieldlabel", NULL, "status");
                $a_xml_writer->xmlElement("fieldentry", NULL, $this->getStatus());
                $a_xml_writer->xmlEndTag("metadatafield");

                $a_xml_writer->xmlStartTag("metadatafield");
                $a_xml_writer->xmlElement("fieldlabel", NULL, "display_question_titles");
                $a_xml_writer->xmlElement("fieldentry", NULL, $this->getShowQuestionTitles());
                $a_xml_writer->xmlEndTag("metadatafield");

                $a_xml_writer->xmlStartTag("metadatafield");
                $a_xml_writer->xmlElement("fieldlabel", NULL, "SCORM");
                include_once "./Services/MetaData/classes/class.ilMD.php";
                $md = new ilMD($this->getId(),0, $this->getType());
                $writer = new ilXmlWriter();
                $md->toXml($writer);
                $metadata = $writer->xmlDumpMem();
                $a_xml_writer->xmlElement("fieldentry", NULL, $metadata);
                $a_xml_writer->xmlEndTag("metadatafield");

                $a_xml_writer->xmlEndTag("metadata");
                $a_xml_writer->xmlEndTag("survey");

                $attribs = array("id" => $this->getId());
                $a_xml_writer->xmlStartTag("surveyquestions", $attribs);
                // add questionblock descriptions
                $obligatory_states =& $this->getObligatoryStates();
                foreach ($pages as $question_array)
                {
                        if (count($question_array) > 1)
                        {
                                $attribs = array("id" => $question_array[0]["question_id"]);
                                $attribs = array("showQuestiontext" => $question_array[0]["questionblock_show_questiontext"]);
                                $a_xml_writer->xmlStartTag("questionblock", $attribs);
                                if (strlen($question_array[0]["questionblock_title"]))
                                {
                                        $a_xml_writer->xmlElement("questionblocktitle", NULL, $question_array[0]["questionblock_title"]);
                                }
                        }
                        foreach ($question_array as $question)
                        {
                                if (strlen($question["heading"]))
                                {
                                        $a_xml_writer->xmlElement("textblock", NULL, $question["heading"]);
                                }
                                $questionObject =& $this->_instanciateQuestion($question["question_id"]);
                                if ($questionObject !== FALSE) $questionObject->insertXML($a_xml_writer, FALSE, $obligatory_states[$question["question_id"]]);
                        }
                        if (count($question_array) > 1)
                        {
                                $a_xml_writer->xmlEndTag("questionblock");
                        }
                }

                $a_xml_writer->xmlEndTag("surveyquestions");
                $a_xml_writer->xmlEndTag("surveyobject");
                $xml = $a_xml_writer->xmlDumpMem(FALSE);
                return $xml;
        }
        
  function &_instanciateQuestion($question_id) 
        {
                if ($question_id < 1) return FALSE;
                include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                $question_type = SurveyQuestion::_getQuestionType($question_id);
                if (strlen($question_type) == 0) return FALSE;
                SurveyQuestion::_includeClass($question_type);
                $question = new $question_type();
                $question->loadFromDb($question_id);
                return $question;
  }

        function locateImportFiles($a_dir)
        {
                if (!is_dir($a_dir) || is_int(strpos($a_dir, "..")))
                {
                        return;
                }
                $importDirectory = "";
                $xmlFile = "";

                $current_dir = opendir($a_dir);
                $files = array();
                while($entryname = readdir($current_dir))
                {
                        $files[] = $entryname;
                }

                foreach($files as $file)
                {
                        if(is_dir($a_dir."/".$file) and ($file != "." and $file!=".."))
                        {
                                // found directory created by zip
                                $importDirectory = $a_dir."/".$file;
                        }
                }
                closedir($current_dir);
                if (strlen($importDirectory))
                {
                        // find the xml file
                        $current_dir = opendir($importDirectory);
                        $files = array();
                        while($entryname = readdir($current_dir))
                        {
                                $files[] = $entryname;
                        }
                        foreach($files as $file)
                        { 
                                if(@is_file($importDirectory."/".$file) && ($file != "." && $file!="..") && (strcmp(strtolower(substr($file, -4, 4)), ".xml") == 0))
                                {
                                        // found xml file
                                        $xmlFile = $importDirectory."/".$file;
                                }
                        }
                }
                return array("dir" => $importDirectory, "xml" => $xmlFile);
        }

        function importObject($file_info, $survey_questionpool_id)
        {
                // check if file was uploaded
                $source = $file_info["tmp_name"];
                $error = "";
                if (($source == 'none') || (!$source) || $file_info["error"] > UPLOAD_ERR_OK)
                {
                        $error = $this->lng->txt("import_no_file_selected");
                }
                // check correct file type
                $isXml = FALSE;
                $isZip = FALSE;
                if ((strcmp($file_info["type"], "text/xml") == 0) || (strcmp($file_info["type"], "application/xml") == 0))
                {
                        $isXml = TRUE;
                }
                if (strpos($file_info["type"], "zip") !== FALSE)
                {
                        $isZip = TRUE;
                }
                if (!$isXml && !$isZip)
                {
                        $error = $this->lng->txt("import_wrong_file_type");
                        global $ilLog;
                        $ilLog->write("Survey: Import error. Filetype was \"" . $file_info["type"] ."\"");
                }
                if (strlen($error) == 0)
                {
                        // import file as a survey
                        $import_dir = $this->getImportDirectory();
                        $import_subdir = "";
                        $importfile = "";
                        include_once "./Services/Utilities/classes/class.ilUtil.php";
                        if ($isZip)
                        {
                                $importfile = $import_dir."/".$file_info["name"];
                                ilUtil::moveUploadedFile($source, $file_info["name"], $importfile);
                                ilUtil::unzip($importfile);
                                $found = $this->locateImportFiles($import_dir);
                                if (!((strlen($found["dir"]) > 0) && (strlen($found["xml"]) > 0)))
                                {
                                        $error = $this->lng->txt("wrong_import_file_structure");
                                        return $error;
                                }
                                $importfile = $found["xml"];
                                $import_subdir = $found["dir"];
                        }
                        else
                        {
                                $importfile = tempnam($import_dir, "survey_import");
                                ilUtil::moveUploadedFile($source, $file_info["name"], $importfile);
                        }
                        $fh = fopen($importfile, "r");
                        if (!$fh)
                        {
                                $error = $this->lng->txt("import_error_opening_file");
                                return $error;
                        }
                        $xml = fread($fh, filesize($importfile));
                        $result = fclose($fh);
                        if (!$result)
                        {
                                $error = $this->lng->txt("import_error_closing_file");
                                return $error;
                        }

                        unset($_SESSION["import_mob_xhtml"]);
                        if (strpos($xml, "questestinterop"))
                        {
                                include_once "./Services/Survey/classes/class.SurveyImportParserPre38.php";
                                include_once "./Modules/SurveyQuestionPool/classes/class.ilObjSurveyQuestionPool.php";
                                $spl = new ilObjSurveyQuestionPool($survey_questionpool_id, FALSE);
                                $import = new SurveyImportParserPre38($spl, "", TRUE);
                                $import->setSurveyObject($this);
                                $import->setXMLContent($xml);
                                $import->startParsing();
                        }
                        else
                        {
                                include_once "./Services/Survey/classes/class.SurveyImportParser.php";
                                include_once "./Modules/SurveyQuestionPool/classes/class.ilObjSurveyQuestionPool.php";
                                $spl = new ilObjSurveyQuestionPool($survey_questionpool_id, FALSE);
                                $import = new SurveyImportParser($spl, "", TRUE);
                                $import->setSurveyObject($this);
                                $import->setXMLContent($xml);
                                $import->startParsing();
                        }

                        if (is_array($_SESSION["import_mob_xhtml"]))
                        {
                                include_once "./Services/MediaObjects/classes/class.ilObjMediaObject.php";
                                include_once "./Services/RTE/classes/class.ilRTE.php";
                                include_once "./Modules/TestQuestionPool/classes/class.ilObjQuestionPool.php";
                                foreach ($_SESSION["import_mob_xhtml"] as $mob)
                                {
                                        $importfile = $import_subdir . "/" . $mob["uri"];
                                        if (file_exists($importfile))
                                        {
                                                $media_object =& ilObjMediaObject::_saveTempFileAsMediaObject(basename($importfile), $importfile, FALSE);
                                                ilObjMediaObject::_saveUsage($media_object->getId(), "svy:html", $this->getId());
                                                $this->setIntroduction(str_replace("src=\"" . $mob["mob"] . "\"", "src=\"" . "il_" . IL_INST_ID . "_mob_" . $media_object->getId() . "\"", $this->getIntroduction()));
                                                $this->setOutro(str_replace("src=\"" . $mob["mob"] . "\"", "src=\"" . "il_" . IL_INST_ID . "_mob_" . $media_object->getId() . "\"", $this->getOutro()));
                                        }
                                        else
                                        {
                                                global $ilLog;
                                                $ilLog->write("Error: Could not open XHTML mob file for test introduction during test import. File $importfile does not exist!");
                                        }
                                }
                                $this->setIntroduction(ilRTE::_replaceMediaObjectImageSrc($this->getIntroduction(), 1));
                                $this->setOutro(ilRTE::_replaceMediaObjectImageSrc($this->getOutro(), 1));
                                $this->saveToDb();
                        }

                        // delete import directory
                        ilUtil::delDir($this->getImportDirectory());
                }
                return $error;
        }

        function &_getAvailableSurveys($use_object_id = false)
        {
                global $ilUser;
                global $ilDB;

                $result_array = array();
                $surveys = ilUtil::_getObjectsByOperations("svy","write", $ilUser->getId(), -1);
                if (count($surveys))
                {
                        $titles = ilObject::_prepareCloneSelection($surveys, "svy");
                        $query = sprintf("SELECT object_data.*, object_reference.ref_id FROM object_data, object_reference WHERE object_data.obj_id = object_reference.obj_id AND object_reference.ref_id IN ('%s') ORDER BY object_data.title",
                                implode("','", $surveys)
                        );
                        $result = $ilDB->query($query);
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                if ($use_object_id)
                                {
                                        $result_array[$row["obj_id"]] = $titles[$row["ref_id"]];
                                }
                                else
                                {
                                        $result_array[$row["ref_id"]] = $titles[$row["ref_id"]];
                                }
                        }
                }
                return $result_array;
        }       
        
        public function cloneObject($a_target_id,$a_copy_id = 0)
        {
                global $ilDB;
                
                $this->loadFromDb();
                
                // Copy settings
                $newObj = parent::cloneObject($a_target_id,$a_copy_id);
                $this->cloneMetaData($newObj);
                
                $newObj->author = $this->getAuthor();
                $newObj->introduction = $this->getIntroduction();
                $newObj->outro = $this->getOutro();
                $newObj->status = $this->getStatus();
                $newObj->evaluation_access = $this->getEvaluationAccess();
                $newObj->start_date = $this->getStartDate();
                $newObj->startdate_enabled = $this->getStartDateEnabled();
                $newObj->end_date = $this->getEndDate();
                $newObj->enddate_enabled = $this->getEndDateEnabled();
                $newObj->invitation = $this->getInvitation();
                $newObj->invitation_mode = $this->getInvitationMode();
                $newObj->anonymize = $this->getAnonymize();

                $question_pointer = array();
                // clone the questions
                $mapping = array();
                include_once "./Modules/SurveyQuestionPool/classes/class.SurveyQuestion.php";
                foreach ($this->questions as $key => $question_id)
                {
                        $question = ilObjSurvey::_instanciateQuestion($question_id);
                        $question->id = -1;
                        $original_id = SurveyQuestion::_getOriginalId($question_id);
                        $question->saveToDb($original_id);
                        $newObj->questions[$key] = $question->getId();
                        $question_pointer[$question_id] = $question->getId();
                        $mapping[$question_id] = $question->getId();
                }

                $newObj->saveToDb();            
                $newObj->cloneTextblocks($mapping);

                // clone the questionblocks
                $questionblocks = array();
                $questionblock_questions = array();
                $query = sprintf("SELECT * FROM survey_questionblock_question WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() > 0)
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                array_push($questionblock_questions, $row);
                                $questionblocks[$row["questionblock_fi"]] = $row["questionblock_fi"];
                        }
                }
                // create new questionblocks
                foreach ($questionblocks as $key => $value)
                {
                        $questionblock = ilObjSurvey::_getQuestionblock($key);
                        $questionblock_id = ilObjSurvey::_addQuestionblock($questionblock["title"], $questionblock["owner_fi"]);
                        $questionblocks[$key] = $questionblock_id;
                }
                // create new questionblock questions
                foreach ($questionblock_questions as $key => $value)
                {
                        $clonequery = sprintf("INSERT INTO survey_questionblock_question (questionblock_question_id, survey_fi, questionblock_fi, question_fi) VALUES (NULL, %s, %s, %s)",
                                $ilDB->quote($newObj->getSurveyId() . ""),
                                $ilDB->quote($questionblocks[$value["questionblock_fi"]] . ""),
                                $ilDB->quote($question_pointer[$value["question_fi"]] . "")
                        );
                        $cloneresult = $ilDB->query($clonequery);
                }
                
                // clone the constraints
                $constraints = ilObjSurvey::_getConstraints($this->getSurveyId());
                foreach ($constraints as $key => $constraint)
                {
                        $newObj->addConstraint($question_pointer[$constraint["for_question"]], $question_pointer[$constraint["question"]], $constraint["relation_id"], $constraint["value"]);
                }
                
                // clone the obligatory states
                $query = sprintf("SELECT * FROM survey_question_obligatory WHERE survey_fi = %s",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() > 0)
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                $clonequery = sprintf("INSERT INTO survey_question_obligatory (question_obligatory_id, survey_fi, question_fi, obligatory, TIMESTAMP) VALUES (NULL, %s, %s, %s, NULL)",
                                        $ilDB->quote($newObj->getSurveyId() . ""),
                                        $ilDB->quote($question_pointer[$row["question_fi"]] . ""),
                                        $ilDB->quote($row["obligatory"])
                                );
                                $cloneresult = $ilDB->query($clonequery);
                        }
                }
                return $newObj;
        }
        
        function getTextblock($question_id)
        {
                global $ilDB;
                $query = sprintf("SELECT * FROM survey_survey_question WHERE question_fi = %s",
                        $ilDB->quote($question_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        return $row["heading"];
                }
                else
                {
                        return "";
                }
        }

        function cloneTextblocks($mapping)
        {
                foreach ($mapping as $original_id => $new_id)
                {
                        $textblock = $this->getTextblock($original_id);
                        include_once "./Services/AdvancedEditing/classes/class.ilObjAdvancedEditing.php";
                        $this->saveHeading(ilUtil::stripSlashes($textblock, TRUE, ilObjAdvancedEditing::_getUsedHTMLTagsAsString("survey")), $new_id);
                }
        }

        function createExportDirectory()
        {
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                $svy_data_dir = ilUtil::getDataDir()."/svy_data";
                ilUtil::makeDir($svy_data_dir);
                if(!is_writable($svy_data_dir))
                {
                        $this->ilias->raiseError("Survey Data Directory (".$svy_data_dir
                                .") not writeable.",$this->ilias->error_obj->FATAL);
                }
                
                // create learning module directory (data_dir/lm_data/lm_<id>)
                $svy_dir = $svy_data_dir."/svy_".$this->getId();
                ilUtil::makeDir($svy_dir);
                if(!@is_dir($svy_dir))
                {
                        $this->ilias->raiseError("Creation of Survey Directory failed.",$this->ilias->error_obj->FATAL);
                }
                // create Export subdirectory (data_dir/lm_data/lm_<id>/Export)
                $export_dir = $svy_dir."/export";
                ilUtil::makeDir($export_dir);
                if(!@is_dir($export_dir))
                {
                        $this->ilias->raiseError("Creation of Export Directory failed.",$this->ilias->error_obj->FATAL);
                }
        }

        function getExportDirectory()
        {
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                $export_dir = ilUtil::getDataDir()."/svy_data"."/svy_".$this->getId()."/export";

                return $export_dir;
        }
        
        function getExportFiles($dir)
        {
                // quit if import dir not available
                if (!@is_dir($dir) or
                        !is_writeable($dir))
                {
                        return array();
                }

                // open directory
                $dir = dir($dir);

                // initialize array
                $file = array();

                // get files and save the in the array
                while ($entry = $dir->read())
                {
                        if ($entry != "." and
                                $entry != ".." and
                                ereg("^[0-9]{10}_{2}[0-9]+_{2}(survey__)*[0-9]+\.xml|zip\$", $entry))
                        {
                                $file[] = $entry;
                        }
                }

                // close import directory
                $dir->close();
                // sort files
                sort ($file);
                reset ($file);

                return $file;
        }

        function createImportDirectory()
        {
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                $svy_data_dir = ilUtil::getDataDir()."/svy_data";
                ilUtil::makeDir($svy_data_dir);
                
                if(!is_writable($svy_data_dir))
                {
                        $this->ilias->raiseError("Survey Data Directory (".$svy_data_dir
                                .") not writeable.",$this->ilias->error_obj->FATAL);
                }

                // create test directory (data_dir/svy_data/svy_<id>)
                $svy_dir = $svy_data_dir."/svy_".$this->getId();
                ilUtil::makeDir($svy_dir);
                if(!@is_dir($svy_dir))
                {
                        $this->ilias->raiseError("Creation of Survey Directory failed.",$this->ilias->error_obj->FATAL);
                }

                // create import subdirectory (data_dir/svy_data/svy_<id>/import)
                $import_dir = $svy_dir."/import";
                ilUtil::makeDir($import_dir);
                if(!@is_dir($import_dir))
                {
                        $this->ilias->raiseError("Creation of Import Directory failed.",$this->ilias->error_obj->FATAL);
                }
        }

        function getImportDirectory()
        {
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                $import_dir = ilUtil::getDataDir()."/svy_data".
                        "/svy_".$this->getId()."/import";
                if (!is_dir($import_dir))
                {
                        ilUtil::makeDirParents($import_dir);
                }
                if(@is_dir($import_dir))
                {
                        return $import_dir;
                }
                else
                {
                        return false;
                }
        }
        
        function saveHeading($heading = "", $insertbefore)
        {
                global $ilDB;
                if ($heading)
                {
                        $query = sprintf("UPDATE survey_survey_question SET heading=%s WHERE survey_fi=%s AND question_fi=%s",
                                $ilDB->quote($heading),
                                $ilDB->quote($this->getSurveyId() . ""),
                                $ilDB->quote($insertbefore)
                        );
                }
                else
                {
                        $query = sprintf("UPDATE survey_survey_question SET heading=NULL WHERE survey_fi=%s AND question_fi=%s",
                                $ilDB->quote($this->getSurveyId() . ""),
                                $ilDB->quote($insertbefore)
                        );
                }
                $ilDB->query($query);
        }

        function _getRefIdFromObjId($obj_id)
        {
                global $ilDB;
                
                $query = sprintf("SELECT ref_id FROM object_reference WHERE obj_id=%s",
                        $ilDB->quote($obj_id)
                        
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        return $row["ref_id"];
                }
                return 0;
        }
        
        function isAnonymousKey($key)
        {
                global $ilDB;
                
                $query = sprintf("SELECT anonymous_id FROM survey_anonymous WHERE survey_key = %s AND survey_fi = %s",
                        $ilDB->quote($key . ""),
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        return true;
                }
                else
                {
                        return false;
                }
        }
        
        function getUserSurveyCode($user_id)
        {
                global $ilDB;
                
                if (($user_id == ANONYMOUS_USER_ID) || (($this->isAccessibleWithoutCode() && $this->isAllowedToTakeMultipleSurveys()))) return "";
                $query = sprintf("SELECT anonymous_id FROM survey_finished WHERE survey_fi = %s AND user_fi = %s",
                        $ilDB->quote($this->getSurveyId() . ""),
                        $ilDB->quote($user_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        return $row["anonymous_id"];
                }
                else
                {
                        return "";
                }
        }
        
        function isAnonymizedParticipant($key)
        {
                global $ilDB;
                
                $query = sprintf("SELECT finished_id FROM survey_finished WHERE anonymous_id = %s AND survey_fi = %s",
                        $ilDB->quote($key . ""),
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows() == 1)
                {
                        return true;
                }
                else
                {
                        return false;
                }
        }
        
        function checkSurveyCode($code)
        {
                if ($this->isAnonymousKey($code))
                {
                        if ($this->isSurveyStarted("", $code) == 1)
                        {
                                return false;
                        }
                        else
                        {
                                return true;
                        }
                }
                else
                {
                        return false;
                }
        }

        function getSurveyCodesCount()
        {
                global $ilDB;

                $query = sprintf("SELECT anonymous_id FROM survey_anonymous WHERE survey_fi = %s AND ISNULL(user_key)",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                return $result->numRows();
        }
        
        function getSurveyCodesForExport($a_array)
        {
                global $ilDB;

/*              $query = sprintf("SELECT * FROM survey_anonymous WHERE survey_fi = %s AND ISNULL(user_key)",
                        $ilDB->quote($this->getSurveyId() . "")
                );
*/
                $query = sprintf("SELECT survey_anonymous.*, survey_anonymous.TIMESTAMP + 0 AS timestamp14, survey_finished.state FROM survey_anonymous LEFT JOIN survey_finished ON survey_anonymous.survey_key = survey_finished.anonymous_id WHERE survey_anonymous.survey_fi = %s AND ISNULL(survey_anonymous.user_key)",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);


                $result = $ilDB->query($query);
                $export = "";
                $lang = ($_POST["lang"] != 1) ? "&amp;lang=" . $_POST["lang"] : "";
                while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                {
                        if (in_array($row["survey_key"], $a_array) || (count($a_array) == 0))
                        {
                                $export .= $row["survey_key"] . ",";
                                
                                // No relative (today, tomorrow...) dates in export.
                                $date = new ilDate($row['timestamp14'],IL_CAL_TIMESTAMP);
                                $created = $date->get(IL_CAL_DATE);
                                $export .= "$created,";
                                if ($this->isSurveyCodeUsed($row["survey_key"]))
                                {
                                        $export .= "1,";
                                }
                                else
                                {
                                        $export .= "0,";
                                }
                                $url = ILIAS_HTTP_PATH."/goto.php?cmd=infoScreen&target=svy_".$this->getRefId() . "&client_id=" . CLIENT_ID . "&accesscode=".$row["survey_key"].$lang;
                                $export .= $url . "\n";
                        }
                }
                return $export;
        }
        
        function &getSurveyCodesTableData($lang = "en", $offset = 0, $limit = 10)
        {
                global $ilDB;

                include_once "./classes/class.ilFormat.php";
                if (strlen($lang) == 0) $lang = "en";
                if (strlen($offset) == 0) $offset = 0;
                if (strlen($limit) == 0) $limit = 10;
                
                $order = "ORDER BY timestamp14, survey_key ASC";
                $codes = array();
                $query = sprintf("SELECT survey_anonymous.anonymous_id, survey_anonymous.survey_key, survey_anonymous.survey_fi, survey_anonymous.TIMESTAMP + 0 AS timestamp14, survey_finished.state FROM survey_anonymous LEFT JOIN survey_finished ON survey_anonymous.survey_key = survey_finished.anonymous_id WHERE survey_anonymous.survey_fi = %s AND ISNULL(survey_anonymous.user_key) $order LIMIT $offset,$limit",
                        $ilDB->quote($this->getSurveyId() . "")
                );
                $result = $ilDB->query($query);
                $counter = $offset+1;
                if ($result->numRows() > 0)
                {
                        while ($row = $result->fetchRow(MDB2_FETCHMODE_ASSOC))
                        {
                                $created = ilDatePresentation::formatDate(new ilDateTime($row["timestamp14"],IL_CAL_TIMESTAMP));

                                $url = "";
                                
                                $state = "<span class=\"smallred\">" . $this->lng->txt("not_used") . "</span>";
                                if ($this->isSurveyCodeUsed($row["survey_key"]))
                                {
                                        $state = "<span class=\"smallgreen\">" . $this->lng->txt("used") . "</span>";
                                }
                                else
                                {
                                        $addlang = "";
                                        if (strlen($lang))
                                        {
                                                $addlang = "&amp;lang=$lang";
                                        }
                                        $url = "<a href=\"" . ILIAS_HTTP_PATH."/goto.php?cmd=infoScreen&target=svy_".$this->getRefId() . "&amp;client_id=" . CLIENT_ID . "&amp;accesscode=".$row["survey_key"].$addlang . "\">";
                                        $url .= $this->lng->txt("survey_code_url_name");
                                        $url .= "</a>";
                                }
                                $counter = "<input type=\"checkbox\" name=\"chb_code[]\" value=\"" . $row["survey_key"] . "\"/>";
                                array_push($codes, array($counter, $row["survey_key"], $created, $state, $url));
                                $counter++;
                        }
                }
                return $codes;
        }

        function isSurveyCodeUsed($code)
        {
                global $ilDB;
                $query = sprintf("SELECT finished_id FROM survey_finished WHERE survey_fi = %s AND anonymous_id = %s",
                        $ilDB->quote($this->getSurveyId() . ""),
                        $ilDB->quote($code)
                );
                $result = $ilDB->query($query);
                if ($result->numRows() > 0)
                {
                        return TRUE;
                }
                else
                {
                        return FALSE;
                }
        }
        
        function createSurveyCodes($nrOfCodes)
        {
                global $ilDB;
                for ($i = 0; $i < $nrOfCodes; $i++)
                {
                        $anonymize_key = $this->createNewAccessCode();
                        $query = sprintf("INSERT INTO survey_anonymous (anonymous_id, survey_key, survey_fi, TIMESTAMP) VALUES (NULL, %s, %s, NULL)",
                                $ilDB->quote($anonymize_key . ""),
                                $ilDB->quote($this->getSurveyId() . "")
                        );
                        $result = $ilDB->query($query);
                }
        }

        function deleteSurveyCode($survey_code)
        {
                global $ilDB;
                
                if (strlen($survey_code) > 0)
                {
                        $query = sprintf("DELETE FROM survey_anonymous WHERE survey_fi = %s AND survey_key = %s",
                                $ilDB->quote($this->getSurveyId() . ""),
                                $ilDB->quote($survey_code)
                        );
                        $ilDB->query($query);
                }
        }
        
        function getUserAccessCode($user_id)
        {
                global $ilDB;
                $access_code = "";
                $query = sprintf("SELECT survey_key FROM survey_anonymous WHERE survey_fi = %s AND user_key = %s",
                        $ilDB->quote($this->getSurveyId() . ""),
                        $ilDB->quote(md5($user_id))
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        $access_code = $row["survey_key"];
                }
                return $access_code;
        }
        
        function saveUserAccessCode($user_id, $access_code)
        {
                global $ilDB;
                $query = sprintf("INSERT INTO survey_anonymous (survey_key, survey_fi, user_key) VALUES (%s, %s, %s)",
                        $ilDB->quote($access_code . ""),
                        $ilDB->quote($this->getSurveyId() . ""),
                        $ilDB->quote(md5($user_id) . "")
                );
                $result = $ilDB->query($query);
        }
        
        function createNewAccessCode()
        {
                // create a 5 character code
                $codestring = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
                mt_srand();
                $code = "";
                for ($i = 1; $i <=5; $i++)
                {
                        $index = mt_rand(0, strlen($codestring)-1);
                        $code .= substr($codestring, $index, 1);
                }
                // verify it against the database
                while ($this->isSurveyCodeUsed($code))
                {
                        $code = $this->createNewAccessCode();
                }
                return $code;
        }
        

        function &processCSVRow($row, $quoteAll = FALSE, $separator = ";")
        {
                $resultarray = array();
                foreach ($row as $rowindex => $entry)
                {
                        $surround = FALSE;
                        if ($quoteAll)
                        {
                                $surround = TRUE;
                        }
                        if (strpos($entry, "\"") !== FALSE)
                        {
                                $entry = str_replace("\"", "\"\"", $entry);
                                $surround = TRUE;
                        }
                        if (strpos($entry, $separator) !== FALSE)
                        {
                                $surround = TRUE;
                        }
                        // replace all CR LF with LF (for Excel for Windows compatibility
                        $entry = str_replace(chr(13).chr(10), chr(10), $entry);
                        if ($surround)
                        {
                                $resultarray[$rowindex] = utf8_decode("\"" . $entry . "\"");
                        }
                        else
                        {
                                $resultarray[$rowindex] = utf8_decode($entry);
                        }
                }
                return $resultarray;
        }

        function _getLastAccess($finished_id)
        {
                global $ilDB;
                
                $query = sprintf("SELECT TIMESTAMP+0 AS timestamp14 FROM survey_answer WHERE active_fi = %s ORDER BY TIMESTAMP DESC",
                        $ilDB->quote($finished_id . "")
                );
                $result = $ilDB->query($query);
                if ($result->numRows())
                {
                        $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                        return $row["timestamp14"];
                }
                else
                {
                        $query = sprintf("SELECT TIMESTAMP+0 AS timestamp14 FROM survey_finished WHERE finished_id = %s",
                                $ilDB->quote($finished_id . "")
                        );
                        $result = $ilDB->query($query);
                        if ($result->numRows())
                        {
                                $row = $result->fetchRow(MDB2_FETCHMODE_ASSOC);
                                return $row["timestamp14"];
                        }
                }
                return "";
        }

        function prepareTextareaOutput($txt_output)
        {
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                return ilUtil::prepareTextareaOutput($txt_output, $prepare_for_latex_output);
        }

        function isHTML($a_text)
        {
                if (preg_match("/<[^>]*?>/", $a_text))
                {
                        return TRUE;
                }
                else
                {
                        return FALSE; 
                }
        }

        function addMaterialTag(&$a_xml_writer, $a_material, $close_material_tag = TRUE, $add_mobs = TRUE, $attribs = NULL)
        {
                include_once "./Services/RTE/classes/class.ilRTE.php";
                include_once("./Services/MediaObjects/classes/class.ilObjMediaObject.php");

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

                if ($add_mobs)
                {
                        $mobs = ilObjMediaObject::_getMobsOfObject("svy:html", $this->getId());
                        foreach ($mobs as $mob)
                        {
                                $mob_id = "il_" . IL_INST_ID . "_mob_" . $mob;
                                if (strpos($mattext, $mob_id) !== FALSE)
                                {
                                        $mob_obj =& new ilObjMediaObject($mob);
                                        $imgattrs = array(
                                                "label" => $mob_id,
                                                "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 canExportSurveyCode()
        {
                if ($this->getAnonymize() != ANONYMIZE_OFF)
                {
                        if ($this->surveyCodeSecurity == FALSE)
                        {
                                return TRUE;
                        }
                }
                return FALSE;
        }

        function processPrintoutput2FO($print_output)
        {
                $print_output = str_replace("&nbsp;", "&#160;", $print_output);
                $print_output = str_replace("&otimes;", "X", $print_output);
                $xsl = file_get_contents("./Modules/Survey/xml/question2fo.xsl");
                $args = array( '/_xml' => $print_output, '/_xsl' => $xsl );
                $xh = xslt_create();
                $params = array();
                $output = xslt_process($xh, "arg:/_xml", "arg:/_xsl", NULL, $args, $params);
                xslt_error($xh);
                xslt_free($xh);
                global $ilLog; $ilLog->write($output);
                return $output;
        }
        
        function deliverPDFfromFO($fo)
        {
                include_once "./Services/Utilities/classes/class.ilUtil.php";
                $fo_file = ilUtil::ilTempnam() . ".fo";
                $fp = fopen($fo_file, "w"); fwrite($fp, $fo); fclose($fp);
                include_once "./Services/Transformation/classes/class.ilFO2PDF.php";
                $fo2pdf = new ilFO2PDF();
                $fo2pdf->setFOString($fo);
                $result = $fo2pdf->send();
                ilUtil::deliverData($result, ilUtil::getASCIIFilename($this->getTitle()) . ".pdf", "application/pdf");
        }
        
        function _checkCondition($a_svy_id,$a_operator,$a_value,$a_usr_id = 0)
        {
                global $ilUser;
                
                $a_usr_id = $a_usr_id ? $a_usr_id : $ilUser->getId();

                switch($a_operator)
                {
                        case 'finished':
                                //if (ilExerciseMembers::_lookupStatus($a_exc_id, $ilias->account->getId()) == "passed")
                                include_once("./Modules/Survey/classes/class.ilObjSurveyAccess.php");
                                if (ilObjSurveyAccess::_lookupFinished($a_svy_id, $a_usr_id))
                                {
                                        return true;
                                }
                                else
                                {
                                        return false;
                                }
                                break;

                        default:
                                return true;
                }
                return true;
        }

        function isPluginActive($a_pname)
        {
                global $ilPluginAdmin;
                if ($ilPluginAdmin->isActive(IL_COMP_MODULE, "SurveyQuestionPool", "svyq", $a_pname))
                {
                        return TRUE;
                }
                else
                {
                        return FALSE;
                }
        }
} // END class.ilObjSurvey
?>