questiontype.php

很棒的在线教学系统

<?php  // $Id: questiontype.php,v 1.26.2.14 2009/02/18 18:04:12 pichetp Exp $

/////////////////
// CALCULATED ///
/////////////////

/// QUESTION TYPE CLASS //////////////////

require_once("$CFG->dirroot/question/type/datasetdependent/abstractqtype.php");


class question_calculated_qtype extends question_dataset_dependent_questiontype {

    // Used by the function custom_generator_tools:
    var $calcgenerateidhasbeenadded = false;

    function name() {
        return 'calculated';
    }

    function get_question_options(&$question) {
        // First get the datasets and default options
         global $CFG;
        if (!$question->options->answers = get_records_sql(
                                "SELECT a.*, c.tolerance, c.tolerancetype, c.correctanswerlength, c.correctanswerformat " .
                                "FROM {$CFG->prefix}question_answers a, " .
                                "     {$CFG->prefix}question_calculated c " .
                                "WHERE a.question = $question->id " .
                                "AND   a.id = c.answer ".
                                "ORDER BY a.id ASC")) {
            notify('Error: Missing question answer for calculated question ' . $question->id . '!');
            return false;
        }

/*
       if(false === parent::get_question_options($question)) {
            return false;
        }

        if (!$options = get_records('question_calculated', 'question', $question->id)) {
            notify("No options were found for calculated question
             #{$question->id}! Proceeding with defaults.");
        //     $options = new Array();
            $options= new stdClass;
            $options->tolerance           = 0.01;
            $options->tolerancetype       = 1; // relative
            $options->correctanswerlength = 2;
            $options->correctanswerformat = 1; // decimals
        }

        // For historic reasons we also need these fields in the answer objects.
        // This should eventually be removed and related code changed to use
        // the values in $question->options instead.
         foreach ($question->options->answers as $key => $answer) {
            $answer = &$question->options->answers[$key]; // for PHP 4.x
           $answer->calcid              = $options->id;
            $answer->tolerance           = $options->tolerance;
            $answer->tolerancetype       = $options->tolerancetype;
            $answer->correctanswerlength = $options->correctanswerlength;
            $answer->correctanswerformat = $options->correctanswerformat;
        }*/

        $virtualqtype = $this->get_virtual_qtype();
        $virtualqtype->get_numerical_units($question);

        if( isset($question->export_process)&&$question->export_process){
            $question->options->datasets = $this->get_datasets_for_export($question);
        }
        return true;
    }

    function get_datasets_for_export(&$question){
        $datasetdefs = array();
        if (!empty($question->id)) {
            global $CFG;
            $sql = "SELECT i.*
                    FROM {$CFG->prefix}question_datasets d,
                         {$CFG->prefix}question_dataset_definitions i
                    WHERE d.question = '$question->id'
                    AND   d.datasetdefinition = i.id
                   ";
            if ($records = get_records_sql($sql)) {
                foreach ($records as $r) {
                    $def = $r ;
                    if ($def->category=='0'){
                        $def->status='private';
                    } else {
                        $def->status='shared';
                    }
                    $def->type ='calculated' ;
                    list($distribution, $min, $max,$dec) = explode(':', $def->options, 4);
                    $def->distribution=$distribution;
                    $def->minimum=$min;
                    $def->maximum=$max;
                    $def->decimals=$dec ;
                     if ($def->itemcount > 0 ) {
                        // get the datasetitems
                        $def->items = array();
                        $sql1= (" SELECT itemnumber, definition, id, value
                        FROM {$CFG->prefix}question_dataset_items
                        WHERE definition = '$def->id' order by itemnumber ASC ");
                        if ($items = get_records_sql($sql1)){
                            $n = 0;
                            foreach( $items as $ii){
                                $n++;
                                $def->items[$n] = new stdClass;
                                $def->items[$n]->itemnumber=$ii->itemnumber;
                                $def->items[$n]->value=$ii->value;
                           }
                           $def->number_of_items=$n ;
                        }
                    }
                    $datasetdefs["1-$r->category-$r->name"] = $def;
                }
            }
        }
        return $datasetdefs ;
    }

    function save_question_options($question) {
        //$options = $question->subtypeoptions;
        // Get old answers:
        global $CFG;

        if (isset($question->answer) && !isset($question->answers)) {
            $question->answers = $question->answer;
        }

        // Get old versions of the objects
        if (!$oldanswers = get_records('question_answers', 'question', $question->id, 'id ASC')) {
            $oldanswers = array();
        }

        if (!$oldoptions = get_records('question_calculated', 'question', $question->id, 'answer ASC')) {
            $oldoptions = array();
        }

        // Save the units.
        $virtualqtype = $this->get_virtual_qtype();
        $result = $virtualqtype->save_numerical_units($question);
        if (isset($result->error)) {
            return $result;
        } else {
            $units = &$result->units;
        }
        // Insert all the new answers
        foreach ($question->answers as $key => $dataanswer) {
            if (  trim($dataanswer) != '' ) {
                $answer = new stdClass;
                $answer->question = $question->id;
                $answer->answer = trim($dataanswer);
                $answer->fraction = $question->fraction[$key];
                $answer->feedback = trim($question->feedback[$key]);

                if ($oldanswer = array_shift($oldanswers)) {  // Existing answer, so reuse it
                    $answer->id = $oldanswer->id;
                    if (! update_record("question_answers", $answer)) {
                        $result->error = "Could not update question answer! (id=$answer->id)";
                        return $result;
                    }
                } else { // This is a completely new answer
                    if (! $answer->id = insert_record("question_answers", $answer)) {
                        $result->error = "Could not insert question answer!";
                        return $result;
                    }
                }

                // Set up the options object
                if (!$options = array_shift($oldoptions)) {
                    $options = new stdClass;
                }
                $options->question  = $question->id;
                $options->answer    = $answer->id;
                $options->tolerance = trim($question->tolerance[$key]);
                $options->tolerancetype  = trim($question->tolerancetype[$key]);
                $options->correctanswerlength  = trim($question->correctanswerlength[$key]);
                $options->correctanswerformat  = trim($question->correctanswerformat[$key]);

                // Save options
                if (isset($options->id)) { // reusing existing record
                    if (! update_record('question_calculated', $options)) {
                        $result->error = "Could not update question calculated options! (id=$options->id)";
                        return $result;
                    }
                } else { // new options
                    if (! insert_record('question_calculated', $options)) {
                        $result->error = "Could not insert question  calculated options!";
                        return $result;
                    }
                }
            }
        }
        // delete old answer records
        if (!empty($oldanswers)) {
            foreach($oldanswers as $oa) {
                delete_records('question_answers', 'id', $oa->id);
            }
        }

        // delete old answer records
        if (!empty($oldoptions)) {
            foreach($oldoptions as $oo) {
                delete_records('question_calculated', 'id', $oo->id);
            }
        }


        if( isset($question->import_process)&&$question->import_process){
            $this->import_datasets($question);
         }
        // Report any problems.
        if (!empty($result->notice)) {
            return $result;
        }
        return true;
    }

    function import_datasets($question){
        $n = count($question->dataset);
        foreach ($question->dataset as $dataset) {
            // name, type, option,
            $datasetdef = new stdClass();
            $datasetdef->name = $dataset->name;
            $datasetdef->type = 1 ;
            $datasetdef->options =  $dataset->distribution.':'.$dataset->min.':'.$dataset->max.':'.$dataset->length;
            $datasetdef->itemcount=$dataset->itemcount;
            if ( $dataset->status =='private'){
                $datasetdef->category = 0;
                $todo='create' ;
            }else if ($dataset->status =='shared' ){
                if ($sharedatasetdefs = get_records_select(
                        'question_dataset_definitions',
                        "type = '1'
                        AND name = '$dataset->name'
                        AND category = '$question->category'
                        ORDER BY id DESC;"
                       )) { // so there is at least one
                    $sharedatasetdef = array_shift($sharedatasetdefs);
                    if ( $sharedatasetdef->options ==  $datasetdef->options ){// identical so use it
                        $todo='useit' ;
                        $datasetdef =$sharedatasetdef ;
                    } else { // different so create a private one
                        $datasetdef->category = 0;
                        $todo='create' ;
                    }
                }else { // no so create one
                    $datasetdef->category =$question->category ;
                    $todo='create' ;
               }
            }
            if (  $todo=='create'){
                if (!$datasetdef->id = insert_record(
                    'question_dataset_definitions', $datasetdef)) {
                    error("Unable to create dataset $defid");
                }
           }
           // Create relation to the dataset:
           $questiondataset = new stdClass;
           $questiondataset->question = $question->id;
           $questiondataset->datasetdefinition = $datasetdef->id;
            if (!insert_record('question_datasets',
                               $questiondataset)) {
                error("Unable to create relation to dataset $dataset->name $todo");
            }
            if ($todo=='create'){ // add the items
                foreach ($dataset->datasetitem as $dataitem ){
                    $datasetitem = new stdClass;
                    $datasetitem->definition=$datasetdef->id ;
                    $datasetitem->itemnumber = $dataitem->itemnumber ;
                    $datasetitem->value = $dataitem->value ;
                    if (!insert_record('question_dataset_items', $datasetitem)) {
                        error("Unable to insert dataset item $item->itemnumber with $item->value for $datasetdef->name");
                    }
                }
            }
        }
    }

    function create_runtime_question($question, $form) {
        $question = parent::create_runtime_question($question, $form);
        $question->options->answers = array();
        foreach ($form->answers as $key => $answer) {
            $a->answer              = trim($form->answer[$key]);
            $a->fraction              = $form->fraction[$key];//new
           $a->tolerance           = $form->tolerance[$key];
            $a->tolerancetype       = $form->tolerancetype[$key];
            $a->correctanswerlength = $form->correctanswerlength[$key];
            $a->correctanswerformat = $form->correctanswerformat[$key];
            $question->options->answers[] = clone($a);
        }

        return $question;
    }

    function validate_form($form) {
        switch($form->wizardpage) {
            case 'question':
                $calculatedmessages = array();
                if (empty($form->name)) {
                    $calculatedmessages[] = get_string('missingname', 'quiz');
                }
                if (empty($form->questiontext)) {
                    $calculatedmessages[] = get_string('missingquestiontext', 'quiz');
                }
                // Verify formulas
                foreach ($form->answers as $key => $answer) {
                    if ('' === trim($answer)) {
                        $calculatedmessages[] =
                            get_string('missingformula', 'quiz');
                    }
                    if ($formulaerrors =
                     qtype_calculated_find_formula_errors($answer)) {
                        $calculatedmessages[] = $formulaerrors;
                    }
                    if (! isset($form->tolerance[$key])) {
                        $form->tolerance[$key] = 0.0;
                    }
                    if (! is_numeric($form->tolerance[$key])) {
                        $calculatedmessages[] =
                            get_string('tolerancemustbenumeric', 'quiz');
                    }
                }

                if (!empty($calculatedmessages)) {
                    $errorstring = "The following errors were found:<br />";
                    foreach ($calculatedmessages as $msg) {
                        $errorstring .= $msg . '<br />';
                    }
                    error($errorstring);
                }

                break;
            default:
                return parent::validate_form($form);
                break;