questiontype.php

很棒的在线教学系统

<?php  // $Id: questiontype.php,v 1.41.2.17 2009/02/13 06:11:59 tjhunt Exp $

///////////////////
/// MULTIANSWER /// (Embedded - cloze)
///////////////////

///
/// The multianswer question type is special in that it
/// depends on a few other question types, i.e.
/// 'multichoice', 'shortanswer' and 'numerical'.
/// These question types have got a few special features that
/// makes them useable by the 'multianswer' question type
///

/// QUESTION TYPE CLASS //////////////////
/**
 * @package questionbank
 * @subpackage questiontypes
 */
class embedded_cloze_qtype extends default_questiontype {

    function name() {
        return 'multianswer';
    }

    function get_question_options(&$question) {
        global $QTYPES;

        // Get relevant data indexed by positionkey from the multianswers table
        if (!$sequence = get_field('question_multianswer', 'sequence', 'question', $question->id)) {
            notify(get_string('noquestions','qtype_multianswer',$question->name));
            $question->options->questions['1']= '';
            return true ;
        }

        $wrappedquestions = get_records_list('question', 'id', $sequence, 'id ASC');

        // We want an array with question ids as index and the positions as values
        $sequence = array_flip(explode(',', $sequence));
        array_walk($sequence, create_function('&$val', '$val++;'));
        //If a question is lost, the corresponding index is null
        // so this null convention is used to test $question->options->questions 
        // before using the values.
        // first all possible questions from sequence are nulled 
        // then filled with the data if available in  $wrappedquestions
        $nbvaliquestion = 0 ;
        foreach($sequence as $seq){
            $question->options->questions[$seq]= '';
        }
        if (isset($wrappedquestions) && is_array($wrappedquestions)){
            foreach ($wrappedquestions as $wrapped) {
                if (!$QTYPES[$wrapped->qtype]->get_question_options($wrapped)) {
                    notify("Unable to get options for questiontype {$wrapped->qtype} (id={$wrapped->id})");                
                }else {
                    // for wrapped questions the maxgrade is always equal to the defaultgrade,
                    // there is no entry in the question_instances table for them
                    $wrapped->maxgrade = $wrapped->defaultgrade;
                    $nbvaliquestion++ ;
                    $question->options->questions[$sequence[$wrapped->id]] = clone($wrapped); // ??? Why do we need a clone here?
                }
            }
        }
        if ($nbvaliquestion == 0 ) {
            notify(get_string('noquestions','qtype_multianswer',$question->name));
        }
        return true;
    }

    function save_question_options($question) {
        global $QTYPES;
        $result = new stdClass;

        // This function needs to be able to handle the case where the existing set of wrapped
        // questions does not match the new set of wrapped questions so that some need to be
        // created, some modified and some deleted
        // Unfortunately the code currently simply overwrites existing ones in sequence. This
        // will make re-marking after a re-ordering of wrapped questions impossible and
        // will also create difficulties if questiontype specific tables reference the id.

        // First we get all the existing wrapped questions
        if (!$oldwrappedids = get_field('question_multianswer', 'sequence', 'question', $question->id)) {
            $oldwrappedquestions = array();
        } else {
            $oldwrappedquestions = get_records_list('question', 'id', $oldwrappedids, 'id ASC');
        }
        $sequence = array();
        foreach($question->options->questions as $wrapped) {
            if (!empty($wrapped)){
            // if we still have some old wrapped question ids, reuse the next of them

                if (is_array($oldwrappedquestions) && $oldwrappedquestion = array_shift($oldwrappedquestions)) {
                    $wrapped->id = $oldwrappedquestion->id;
                    if($oldwrappedquestion->qtype != $wrapped->qtype ) {
                        switch ($oldwrappedquestion->qtype) {
                        case 'multichoice':
                                 delete_records('question_multichoice', 'question' , $oldwrappedquestion->id );
                            break;
                        case 'shortanswer':
                                 delete_records('question_shortanswer', 'question' , $oldwrappedquestion->id );
                            break;
                        case 'numerical':
                                 delete_records('question_numerical', 'question' , $oldwrappedquestion->id );
                            break;
                        default:
                                print_error('qtypenotrecognized', 'qtype_multianswer','',$oldwrappedquestion->qtype);
                                        $wrapped->id = 0 ;
                            }
                    }
                }else {
                    $wrapped->id = 0 ;
                }
            }
            $wrapped->name = $question->name;
            $wrapped->parent = $question->id;
            $previousid = $wrapped->id ;
            $wrapped->category = $question->category . ',1'; // save_question strips this extra bit off again.
            $wrapped = $QTYPES[$wrapped->qtype]->save_question($wrapped,
                    $wrapped, $question->course);
            $sequence[] = $wrapped->id;
            if ($previousid != 0 && $previousid != $wrapped->id ) { 
                // for some reasons a new question has been created
                // so delete the old one
                delete_question($previousid) ;
            }
        }

        // Delete redundant wrapped questions
        if(is_array($oldwrappedquestions) && count($oldwrappedquestions)){
            foreach ($oldwrappedquestions as $oldwrappedquestion) {
                delete_question($oldwrappedquestion->id) ;
            }
        }

        if (!empty($sequence)) {
            $multianswer = new stdClass;
            $multianswer->question = $question->id;
            $multianswer->sequence = implode(',', $sequence);
            if ($oldid = get_field('question_multianswer', 'id', 'question', $question->id)) {
                $multianswer->id = $oldid;
                if (!update_record("question_multianswer", $multianswer)) {
                    $result->error = "Could not update cloze question options! " .
                            "(id=$multianswer->id)";
                    return $result;
                }
            } else {
                if (!insert_record("question_multianswer", $multianswer)) {
                    $result->error = "Could not insert cloze question options!";
                    return $result;
                }
            }
        }
    }

    function save_question($authorizedquestion, $form, $course) {
        $question = qtype_multianswer_extract_question($form->questiontext);
        if (isset($authorizedquestion->id)) {
            $question->id = $authorizedquestion->id;
        }

        $question->category = $authorizedquestion->category;
        $form->course = $course; // To pass the course object to
                                 // save_question_options, where it is
                                 // needed to call type specific
                                 // save_question methods.
        $form->defaultgrade = $question->defaultgrade;
        $form->questiontext = $question->questiontext;
        $form->questiontextformat = 0;
        $form->options = clone($question->options);
        unset($question->options);
        return parent::save_question($question, $form, $course);
    }

    function create_session_and_responses(&$question, &$state, $cmoptions, $attempt) {
        $state->responses = array();
        foreach ($question->options->questions as $key => $wrapped) {
            $state->responses[$key] = '';
        }
        return true;
    }

    function restore_session_and_responses(&$question, &$state) {
        $responses = explode(',', $state->responses['']);
        $state->responses = array();
        foreach ($responses as $response) {
            $tmp = explode("-", $response);
            // restore encoded characters
            $state->responses[$tmp[0]] = str_replace(array("&#0044;", "&#0045;"),
                    array(",", "-"), $tmp[1]);
        }
        return true;
    }

    function save_session_and_responses(&$question, &$state) {
        $responses = $state->responses;
        // encode - (hyphen) and , (comma) to &#0045; because they are used as
        // delimiters
        array_walk($responses, create_function('&$val, $key',
                '$val = str_replace(array(",", "-"), array("&#0044;", "&#0045;"), $val);
                $val = "$key-$val";'));
        $responses = implode(',', $responses);

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

    /**
    * Deletes question from the question-type specific tables
    *
    * @return boolean Success/Failure
    * @param object $question  The question being deleted
    */
    function delete_question($questionid) {
        delete_records("question_multianswer", "question", $questionid);
        return true;
    }

    function get_correct_responses(&$question, &$state) {
        global $QTYPES;
        $responses = array();
        foreach($question->options->questions as $key => $wrapped) {
            if (  !empty($wrapped)){
                if ($correct = $QTYPES[$wrapped->qtype]->get_correct_responses($wrapped, $state)) {
                    $responses[$key] = $correct[''];
                } else {
                    // if there is no correct answer to this subquestion then there
                    // can not be a correct answer to the whole question either, so
                    // we have to return null.
                    return null;
                }
            }
        }
        return $responses;
    }

    function print_question_formulation_and_controls(&$question, &$state, $cmoptions, $options) {

        global $QTYPES, $CFG, $USER;
        $readonly = empty($options->readonly) ? '' : 'readonly="readonly"';
        $disabled = empty($options->readonly) ? '' : 'disabled="disabled"';
        $formatoptions = new stdClass;
        $formatoptions->noclean = true;
        $formatoptions->para = false;
        $nameprefix = $question->name_prefix;

        // adding an icon with alt to warn user this is a fill in the gap question
        // MDL-7497
        if (!empty($USER->screenreader)) {
            echo "<img src=\"$CFG->wwwroot/question/type/$question->qtype/icon.gif\" ".
                "class=\"icon\" alt=\"".get_string('clozeaid','qtype_multichoice')."\" />  ";
        }

        echo '<div class="ablock clearfix">';
        // For this question type, we better print the image on top:
        if ($image = get_question_image($question)) {
            echo('<img class="qimage" src="' . $image . '" alt="" /><br />');
        }

        $qtextremaining = format_text($question->questiontext,
                $question->questiontextformat, $formatoptions, $cmoptions->course);

        $strfeedback = get_string('feedback', 'quiz');

        // The regex will recognize text snippets of type {#X}
        // where the X can be any text not containg } or white-space characters.

        while (ereg('\{#([^[:space:]}]*)}', $qtextremaining, $regs)) {
            $qtextsplits = explode($regs[0], $qtextremaining, 2);
            echo $qtextsplits[0];
            echo "<label>"; // MDL-7497
            $qtextremaining = $qtextsplits[1];

            $positionkey = $regs[1];
            if (isset($question->options->questions[$positionkey]) && $question->options->questions[$positionkey] != ''){
            $wrapped = &$question->options->questions[$positionkey];
            $answers = &$wrapped->options->answers;
           // $correctanswers = $QTYPES[$wrapped->qtype]->get_correct_responses($wrapped, $state);

            $inputname = $nameprefix.$positionkey;
            if (isset($state->responses[$positionkey])) {
                $response = $state->responses[$positionkey];
            } else {
                $response = null;
            }

            // Determine feedback popup if any
            $popup = '';
            $style = '';
            $feedbackimg = '';
            $feedback = '' ;
            $correctanswer = '';
            $strfeedbackwrapped  = $strfeedback;
                $testedstate = clone($state);
                if ($correctanswers =  $QTYPES[$wrapped->qtype]->get_correct_responses($wrapped, $testedstate)) {
                    if ($options->readonly && $options->correct_responses) {
                        $delimiter = '';
                        if ($correctanswers) {
                            foreach ($correctanswers as $ca) {
                                switch($wrapped->qtype){
                                    case 'numerical':
                                    case 'shortanswer':
                                        $correctanswer .= $delimiter.$ca;
                                        break ;
                                    case 'multichoice':
                                        if (isset($answers[$ca])){
                                            $correctanswer .= $delimiter.$answers[$ca]->answer;
                                        }
                                        break ;
                                }
                                $delimiter = ', ';
                            }
                        }
                    }
                    if ($correctanswer) {
                        $feedback = '<div class="correctness">';
                        $feedback .= get_string('correctansweris', 'quiz', s($correctanswer, true));
                        $feedback .= '</div>';
                    }
                }
            if ($options->feedback) {
                $chosenanswer = null;
                switch ($wrapped->qtype) {
                    case 'numerical':
                    case 'shortanswer':
                        $testedstate = clone($state);
                        $testedstate->responses[''] = $response;
                        foreach ($answers as $answer) {
                            if($QTYPES[$wrapped->qtype]
                                    ->test_response($wrapped, $testedstate, $answer)) {
                                $chosenanswer = clone($answer);
                                break;
                            }
                        }
                        break;
                    case 'multichoice':
                        if (isset($answers[$response])) {