abstractqtype.php

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<?php  // $Id: abstractqtype.php,v 1.16.2.4 2009/02/10 05:40:13 tjhunt Exp $

///////////////////////////////////////////////////////////////
/// ABSTRACT SUPERCLASS FOR QUSTION TYPES THAT USE DATASETS ///
///////////////////////////////////////////////////////////////
/**
 * @package questionbank
 * @subpackage questiontypes
 */

require_once($CFG->libdir.'/filelib.php');

define("LITERAL", "1");
define("FILE", "2");
define("LINK", "3");

class question_dataset_dependent_questiontype extends default_questiontype {

    var $virtualqtype = false;

    function name() {
        return 'datasetdependent';
    }

    function save_question_options($question) {
        // Default does nothing...
        return true;
    }

    function create_session_and_responses(&$question, &$state, $cmoptions, $attempt) {
        // Find out how many datasets are available
        global $CFG;
        if(!$maxnumber = (int)get_field_sql(
                            "SELECT MIN(a.itemcount)
                            FROM {$CFG->prefix}question_dataset_definitions a,
                                 {$CFG->prefix}question_datasets b
                            WHERE b.question = $question->id
                            AND   a.id = b.datasetdefinition")) {
            error("Couldn't get the specified dataset for a calculated " .
                  "question! (question: {$question->id}");
        }

        // Choose a random dataset
        $state->options->datasetitem = rand(1, $maxnumber);
        $state->options->dataset =
         $this->pick_question_dataset($question,$state->options->datasetitem);
        $state->responses = array('' => '');
        return true;
    }

    function restore_session_and_responses(&$question, &$state) {
        if (!ereg('^dataset([0-9]+)[^-]*-(.*)$',
                $state->responses[''], $regs)) {
            notify ("Wrongly formatted raw response answer " .
                   "{$state->responses['']}! Could not restore session for " .
                   " question #{$question->id}.");
            $state->options->datasetitem = 1;
            $state->options->dataset = array();
            $state->responses = array('' => '');
            return false;
        }

        // Restore the chosen dataset
        $state->options->datasetitem = $regs[1];
        $state->options->dataset =
         $this->pick_question_dataset($question,$state->options->datasetitem);
        $state->responses = array('' => $regs[2]);
        return true;
    }

    function save_session_and_responses(&$question, &$state) {
        $responses = 'dataset'.$state->options->datasetitem.'-'.
         $state->responses[''];

        // Set the legacy answer field
        if (!set_field('question_states', 'answer', $responses, 'id',
         $state->id)) {
            return false;
        }
        return true;
    }


    function substitute_variables($str, $dataset) {
        foreach ($dataset as $name => $value) {
            if($value < 0 ){
                $str = str_replace('{'.$name.'}', '('.$value.')', $str);
            } else {
            $str = str_replace('{'.$name.'}', $value, $str);
        }
        }
        return $str;
    }

    function finished_edit_wizard(&$form) {
        return isset($form->backtoquiz);
    }

    // This gets called by editquestion.php after the standard question is saved
    function print_next_wizard_page(&$question, &$form, $course) {
        global $CFG, $USER, $SESSION, $COURSE;

        // Catch invalid navigation & reloads
        if (empty($question->id) && empty($SESSION->datasetdependent)) {
            redirect('edit.php?courseid='.$COURSE->id, 'The page you are loading has expired.', 3);
        }

        // See where we're coming from
        switch($form->wizardpage) {
            case 'question':
                require("$CFG->dirroot/question/type/datasetdependent/datasetdefinitions.php");
                break;
            case 'datasetdefinitions':
            case 'datasetitems':
                require("$CFG->dirroot/question/type/datasetdependent/datasetitems.php");
                break;
            default:
                error('Incorrect or no wizard page specified!');
                break;
        }
    }

    // This gets called by question2.php after the standard question is saved
    function &next_wizard_form($submiturl, $question, $wizardnow){
        global $CFG, $SESSION, $COURSE;

        // Catch invalid navigation & reloads
        if (empty($question->id) && empty($SESSION->datasetdependent)) {
            redirect('edit.php?courseid='.$COURSE->id, 'The page you are loading has expired. Cannot get next wizard form.', 3);
        }
        if (empty($question->id)){
            $question =& $SESSION->datasetdependent->questionform;
        }

        // See where we're coming from
        switch($wizardnow) {
            case 'datasetdefinitions':
                require("$CFG->dirroot/question/type/datasetdependent/datasetdefinitions_form.php");
                $mform =& new question_dataset_dependent_definitions_form("$submiturl?wizardnow=datasetdefinitions", $question);
                break;
            case 'datasetitems':
                require("$CFG->dirroot/question/type/datasetdependent/datasetitems_form.php");
                $regenerate = optional_param('forceregeneration', 0, PARAM_BOOL);
                $mform =& new question_dataset_dependent_items_form("$submiturl?wizardnow=datasetitems", $question, $regenerate);
                break;
            default:
                error('Incorrect or no wizard page specified!');
                break;
        }

        return $mform;
    }

    /**
     * This method should be overriden if you want to include a special heading or some other
     * html on a question editing page besides the question editing form.
     *
     * @param question_edit_form $mform a child of question_edit_form
     * @param object $question
     * @param string $wizardnow is '' for first page.
     */
    function display_question_editing_page(&$mform, $question, $wizardnow){
        switch ($wizardnow){
            case '':
                //on first page default display is fine
                parent::display_question_editing_page($mform, $question, $wizardnow);
                return;
                break;
            case 'datasetdefinitions':
                print_heading_with_help(get_string("choosedatasetproperties", "quiz"), "questiondatasets", "quiz");
                break;
            case 'datasetitems':
                print_heading_with_help(get_string("editdatasets", "quiz"), 'questiondatasets', "quiz");
                break;
        }


        $mform->display();

    }

     /**
     * This method prepare the $datasets in a format similar to dadatesetdefinitions_form.php
     * so that they can be saved
     * using the function save_dataset_definitions($form)
     *  when creating a new calculated question or
     *  whenediting an already existing calculated question
     * or by  function save_as_new_dataset_definitions($form, $initialid)
     *  when saving as new an already existing calculated question
     *
     * @param object $form
     * @param int $questionfromid default = '0'
     */
    function preparedatasets(&$form , $questionfromid='0'){
        // the dataset names present in the edit_question_form and edit_calculated_form are retrieved
        $possibledatasets = $this->find_dataset_names($form->questiontext);
        $mandatorydatasets = array();
            foreach ($form->answers as $answer) {
                $mandatorydatasets += $this->find_dataset_names($answer);
            }
        // if there are identical datasetdefs already saved in the original question.
        // either when editing a question or saving as new
        // they are retrieved using $questionfromid
        if ($questionfromid!='0'){
            $form->id = $questionfromid ;
        }
        $datasets = array();
        $key = 0 ;
        // always prepare the mandatorydatasets present in the answers
        // the $options are not used here
        foreach ($mandatorydatasets as $datasetname) {
            if (!isset($datasets[$datasetname])) {
                list($options, $selected) =
                        $this->dataset_options($form, $datasetname);
                $datasets[$datasetname]='';
                 $form->dataset[$key]=$selected ;
                $key++;
            }
        }
        // do not prepare possibledatasets when creating a question
        // they will defined and stored with datasetdefinitions_form.php
        // the $options are not used here
        if ($questionfromid!='0'){

        foreach ($possibledatasets as $datasetname) {
            if (!isset($datasets[$datasetname])) {
                list($options, $selected) =
                        $this->dataset_options($form, $datasetname,false);
                $datasets[$datasetname]='';
                 $form->dataset[$key]=$selected ;
                $key++;
            }
        }
        }
     return $datasets ;
     }
    /**
    * this version save the available data at the different steps of the question editing process
    * without using global $SESSION as storage between steps
    * at the first step $wizardnow = 'question'
    *  when creating a new question
    *  when modifying a question
    *  when copying as a new question
    *  the general parameters and answers are saved using parent::save_question
    *  then the datasets are prepared and saved
    * at the second step $wizardnow = 'datasetdefinitions'
    *  the datadefs final type are defined as private, category or not a datadef
    * at the third step $wizardnow = 'datasetitems'
    *  the datadefs parameters and the data items are created or defined
    *
    * @param object question