questiontype.php

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<?php  // $Id: questiontype.php,v 1.20.2.12 2009/03/16 01:52:24 tjhunt Exp $

///////////////////
/// SHORTANSWER ///
///////////////////

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

///
/// This class contains some special features in order to make the
/// question type embeddable within a multianswer (cloze) question
///
/**
 * @package questionbank
 * @subpackage questiontypes
 */
require_once("$CFG->dirroot/question/type/questiontype.php");

class question_shortanswer_qtype extends default_questiontype {

    function name() {
        return 'shortanswer';
    }

    function extra_question_fields() {
        return array('question_shortanswer','answers','usecase');
    }

    function questionid_column_name() {
        return 'question';
    }

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

        if (!$oldanswers = get_records('question_answers', 'question', $question->id, 'id ASC')) {
            $oldanswers = array();
        }

        $answers = array();
        $maxfraction = -1;

        // Insert all the new answers
        foreach ($question->answer as $key => $dataanswer) {
            // Check for, and ingore, completely blank answer from the form.
            if (trim($dataanswer) == '' && $question->fraction[$key] == 0 &&
                    html_is_blank($question->feedback[$key])) {
                continue;
            }

            if ($oldanswer = array_shift($oldanswers)) {  // Existing answer, so reuse it
                $answer = $oldanswer;
                $answer->answer   = trim($dataanswer);
                $answer->fraction = $question->fraction[$key];
                $answer->feedback = $question->feedback[$key];
                if (!update_record("question_answers", $answer)) {
                    $result->error = "Could not update quiz answer! (id=$answer->id)";
                    return $result;
                }
            } else {    // This is a completely new answer
                $answer = new stdClass;
                $answer->answer   = trim($dataanswer);
                $answer->question = $question->id;
                $answer->fraction = $question->fraction[$key];
                $answer->feedback = $question->feedback[$key];
                if (!$answer->id = insert_record("question_answers", $answer)) {
                    $result->error = "Could not insert quiz answer!";
                    return $result;
                }
            }
            $answers[] = $answer->id;
            if ($question->fraction[$key] > $maxfraction) {
                $maxfraction = $question->fraction[$key];
            }
        }

        $question->answers = implode(',', $answers);
        $parentresult = parent::save_question_options($question);
        if($parentresult !== null) { // Parent function returns null if all is OK
            return $parentresult;
        }

        // delete old answer records
        if (!empty($oldanswers)) {
            foreach($oldanswers as $oa) {
                delete_records('question_answers', 'id', $oa->id);
            }
        }

        /// Perform sanity checks on fractional grades
        if ($maxfraction != 1) {
            $maxfraction = $maxfraction * 100;
            $result->noticeyesno = get_string("fractionsnomax", "quiz", $maxfraction);
            return $result;
        } else {
            return true;
        }
    }

    function print_question_formulation_and_controls(&$question, &$state, $cmoptions, $options) {
        global $CFG;
    /// This implementation is also used by question type 'numerical'
        $readonly = empty($options->readonly) ? '' : 'readonly="readonly"';
        $formatoptions = new stdClass;
        $formatoptions->noclean = true;
        $formatoptions->para = false;
        $nameprefix = $question->name_prefix;

        /// Print question text and media

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

        /// Print input controls

        if (isset($state->responses['']) && $state->responses[''] != '') {
            $value = ' value="'.s($state->responses[''], true).'" ';
        } else {
            $value = ' value="" ';
        }
        $inputname = ' name="'.$nameprefix.'" ';

        $feedback = '';
        $class = '';
        $feedbackimg = '';

        if ($options->feedback) {
            $class = question_get_feedback_class(0);
            $feedbackimg = question_get_feedback_image(0);
            foreach($question->options->answers as $answer) {

                if ($this->test_response($question, $state, $answer)) {
                    // Answer was correct or partially correct.
                    $class = question_get_feedback_class($answer->fraction);
                    $feedbackimg = question_get_feedback_image($answer->fraction);
                    if ($answer->feedback) {
                        $feedback = format_text($answer->feedback, true, $formatoptions, $cmoptions->course);
                    }
                    break;
                }
            }
        }

        /// Removed correct answer, to be displayed later MDL-7496
        include("$CFG->dirroot/question/type/shortanswer/display.html");
    }

    function check_response(&$question, &$state) {
        foreach($question->options->answers as $aid => $answer) {
            if ($this->test_response($question, $state, $answer)) {
                return $aid;
            }
        }
        return false;
    }

    function compare_responses($question, $state, $teststate) {
        if (isset($state->responses['']) && isset($teststate->responses[''])) {
            return $state->responses[''] === $teststate->responses[''];
        }
        return false;
    }

    function test_response(&$question, $state, $answer) {
        // Trim the response before it is saved in the database. See MDL-10709
        $state->responses[''] = trim($state->responses['']);
        return $this->compare_string_with_wildcard(stripslashes_safe($state->responses['']),
                $answer->answer, !$question->options->usecase);
    }

    function compare_string_with_wildcard($string, $pattern, $ignorecase) {
        // Break the string on non-escaped asterisks.
        $bits = preg_split('/(?<!\\\\)\*/', $pattern);
        // Escape regexp special characters in the bits.
        $excapedbits = array();
        foreach ($bits as $bit) {
            $excapedbits[] = preg_quote(str_replace('\*', '*', $bit));
        }
        // Put it back together to make the regexp.
        $regexp = '|^' . implode('.*', $excapedbits) . '$|u';

        // Make the match insensitive if requested to.
        if ($ignorecase) {
            $regexp .= 'i';
        }

        return preg_match($regexp, trim($string));
    }

    /*
     * Override the parent class method, to remove escaping from asterisks.
     */
    function get_correct_responses(&$question, &$state) {