format.php

很棒的在线教学系统

<?php // $Id: format.php,v 1.41.2.9 2009/03/16 14:20:24 thepurpleblob Exp $
//
///////////////////////////////////////////////////////////////
// XML import/export
//
//////////////////////////////////////////////////////////////////////////
// Based on default.php, included by ../import.php
/**
 * @package questionbank
 * @subpackage importexport
 */
require_once( "$CFG->libdir/xmlize.php" );

class qformat_xml extends qformat_default {

    function provide_import() {
        return true;
    }

    function provide_export() {
        return true;
    }

    // IMPORT FUNCTIONS START HERE

    /** 
     * Translate human readable format name
     * into internal Moodle code number
     * @param string name format name from xml file
     * @return int Moodle format code
     */
    function trans_format( $name ) {
        $name = trim($name); 
 
        if ($name=='moodle_auto_format') {
            $id = 0;
        }
        elseif ($name=='html') {
            $id = 1;
        }
        elseif ($name=='plain_text') {
            $id = 2;
        }
        elseif ($name=='wiki_like') {
            $id = 3;
        }
        elseif ($name=='markdown') {
            $id = 4;
        }
        else {
            $id = 0; // or maybe warning required
        }
        return $id;
    }

    /**
     * Translate human readable single answer option
     * to internal code number
     * @param string name true/false
     * @return int internal code number
     */
    function trans_single( $name ) {
        $name = trim($name);
        if ($name == "false" || !$name) {
            return 0;
        } else {
            return 1;
        }
    }

    /**
     * process text string from xml file
     * @param array $text bit of xml tree after ['text']
     * @return string processed text
     */
    function import_text( $text ) {
        // quick sanity check
        if (empty($text)) {
            return '';
        }
        $data = $text[0]['#'];
        return addslashes(trim( $data ));
    }

    /**
     * return the value of a node, given a path to the node
     * if it doesn't exist return the default value
     * @param array xml data to read
     * @param array path path to node expressed as array 
     * @param mixed default 
     * @param bool istext process as text
     * @param string error if set value must exist, return false and issue message if not
     * @return mixed value
     */
    function getpath( $xml, $path, $default, $istext=false, $error='' ) {
        foreach ($path as $index) {
            if (!isset($xml[$index])) {
                if (!empty($error)) {
                    $this->error( $error );
                    return false;
                } else {
                    return $default;
                }
            }
            else $xml = $xml[$index];
        }
        if ($istext) {
            if (!is_string($xml)) {
                $this->error( get_string('invalidxml','qformat_xml') );
            }
            $xml = addslashes( trim( $xml ) );
        }

        return $xml;
    }


    /**
     * import parts of question common to all types
     * @param $question array question question array from xml tree
     * @return object question object
     */
    function import_headers( $question ) {
        // get some error strings
        $error_noname = get_string( 'xmlimportnoname','quiz' );
        $error_noquestion = get_string( 'xmlimportnoquestion','quiz' );

        // this routine initialises the question object
        $qo = $this->defaultquestion();

        // question name
        $qo->name = $this->getpath( $question, array('#','name',0,'#','text',0,'#'), '', true, $error_noname );
        $qo->questiontext = $this->getpath( $question, array('#','questiontext',0,'#','text',0,'#'), '', true );
        $qo->questiontextformat = $this->getpath( $question, array('#','questiontext',0,'@','format'), '' );
        $qo->image = $this->getpath( $question, array('#','image',0,'#'), $qo->image );
        $image_base64 = $this->getpath( $question, array('#','image_base64','0','#'),'' );
        if (!empty($image_base64)) {
            $qo->image = $this->importimagefile( $qo->image, stripslashes($image_base64) );
        }
        $qo->generalfeedback = $this->getpath( $question, array('#','generalfeedback',0,'#','text',0,'#'), $qo->generalfeedback, true );
        $qo->defaultgrade = $this->getpath( $question, array('#','defaultgrade',0,'#'), $qo->defaultgrade );
        $qo->penalty = $this->getpath( $question, array('#','penalty',0,'#'), $qo->penalty );

        return $qo;
    }

    /**
     * import the common parts of a single answer
     * @param array answer xml tree for single answer
     * @return object answer object
     */   
    function import_answer( $answer ) {
        $fraction = $this->getpath( $answer, array('@','fraction'),0 );
        $text = $this->getpath( $answer, array('#','text',0,'#'), '', true );
        $feedback = $this->getpath( $answer, array('#','feedback',0,'#','text',0,'#'), '', true );

        $ans = null;
        $ans->answer = $text;
        $ans->fraction = $fraction / 100;
        $ans->feedback = $feedback;
        return $ans;
    }

    /**
     * import multiple choice question 
     * @param array question question array from xml tree
     * @return object question object
     */
    function import_multichoice( $question ) {
        // get common parts
        $qo = $this->import_headers( $question );

        // 'header' parts particular to multichoice
        $qo->qtype = MULTICHOICE;
        $single = $this->getpath( $question, array('#','single',0,'#'), 'true' );
        $qo->single = $this->trans_single( $single );
        $shuffleanswers = $this->getpath( $question, array('#','shuffleanswers',0,'#'), 'false' );
        $qo->answernumbering = $this->getpath( $question, array('#','answernumbering',0,'#'), 'abc' );
        $qo->shuffleanswers = $this->trans_single($shuffleanswers);
        $qo->correctfeedback = $this->getpath( $question, array('#','correctfeedback',0,'#','text',0,'#'), '', true );
        $qo->partiallycorrectfeedback = $this->getpath( $question, array('#','partiallycorrectfeedback',0,'#','text',0,'#'), '', true );
        $qo->incorrectfeedback = $this->getpath( $question, array('#','incorrectfeedback',0,'#','text',0,'#'), '', true );

        // There was a time on the 1.8 branch when it could output an empty answernumbering tag, so fix up any found.
        if (empty($qo->answernumbering)) {
            $qo->answernumbering = 'abc';
        }

        // run through the answers
        $answers = $question['#']['answer'];  
        $a_count = 0;
        foreach ($answers as $answer) {
            $ans = $this->import_answer( $answer );
            $qo->answer[$a_count] = $ans->answer;
            $qo->fraction[$a_count] = $ans->fraction;
            $qo->feedback[$a_count] = $ans->feedback;
            ++$a_count;
        }
        return $qo;
    }

    /**
     * import cloze type question
     * @param array question question array from xml tree
     * @return object question object
     */
    function import_multianswer( $questions ) {
        $questiontext = $questions['#']['questiontext'][0]['#']['text'];
        $qo = qtype_multianswer_extract_question($this->import_text($questiontext));

        // 'header' parts particular to multianswer
        $qo->qtype = MULTIANSWER;
        $qo->course = $this->course;
        $qo->generalfeedback = $this->getpath( $questions, array('#','generalfeedback',0,'#','text',0,'#'), '', true );

        if (!empty($questions)) {
            $qo->name = $this->import_text( $questions['#']['name'][0]['#']['text'] );
        }

        return $qo;
    }

    /**
     * import true/false type question
     * @param array question question array from xml tree
     * @return object question object
     */
    function import_truefalse( $question ) {
        // get common parts
        $qo = $this->import_headers( $question );

        // 'header' parts particular to true/false
        $qo->qtype = TRUEFALSE;

        // get answer info
        //
        // In the past, it used to be assumed that the two answers were in the file
        // true first, then false. Howevever that was not always true. Now, we
        // try to match on the answer text, but in old exports, this will be a localised
        // string, so if we don't find true or false, we fall back to the old system.
        $first = true;
        $warning = false;
        foreach ($question['#']['answer'] as $answer) {
            $answertext = $this->getpath( $answer, array('#','text',0,'#'), '', true );
            $feedback = $this->getpath($answer, array('#','feedback',0,'#','text',0,'#'), '', true );
            if ($answertext != 'true' && $answertext != 'false') {
                $warning = true;
                $answertext = $first ? 'true' : 'false'; // Old style file, assume order is true/false.
            } 
            if ($answertext == 'true') {
                $qo->answer = ($answer['@']['fraction'] == 100);
                $qo->correctanswer = $qo->answer;
                $qo->feedbacktrue = $feedback;
            } else {
                $qo->answer = ($answer['@']['fraction'] != 100);
                $qo->correctanswer = $qo->answer;
                $qo->feedbackfalse = $feedback;
            }
            $first = false;
        }

        if ($warning) {
            $a = new stdClass;
            $a->questiontext = $qo->questiontext;
            $a->answer = get_string($qo->answer ? 'true' : 'false', 'quiz');
            notify(get_string('truefalseimporterror', 'quiz', $a));
        }
        return $qo;
    }

    /**
     * import short answer type question
     * @param array question question array from xml tree
     * @return object question object
     */
    function import_shortanswer( $question ) {
        // get common parts
        $qo = $this->import_headers( $question );

        // header parts particular to shortanswer
        $qo->qtype = SHORTANSWER;

        // get usecase
        $qo->usecase = $this->getpath($question, array('#','usecase',0,'#'), $qo->usecase );

        // run through the answers
        $answers = $question['#']['answer'];  
        $a_count = 0;
        foreach ($answers as $answer) {
            $ans = $this->import_answer( $answer );
            $qo->answer[$a_count] = $ans->answer;
            $qo->fraction[$a_count] = $ans->fraction;
            $qo->feedback[$a_count] = $ans->feedback;
            ++$a_count;
        }

        return $qo;
    }
    
    /**
     * import description type question
     * @param array question question array from xml tree
     * @return object question object
     */
    function import_description( $question ) {
        // get common parts
        $qo = $this->import_headers( $question );
        // header parts particular to shortanswer
        $qo->qtype = DESCRIPTION;
        $qo->defaultgrade = 0;
        $qo->length = 0;
        return $qo;
    }

    /**
     * import numerical type question
     * @param array question question array from xml tree
     * @return object question object
     */
    function import_numerical( $question ) {
        // get common parts
        $qo = $this->import_headers( $question );

        // header parts particular to numerical
        $qo->qtype = NUMERICAL;

        // get answers array
        $answers = $question['#']['answer'];
        $qo->answer = array();
        $qo->feedback = array();
        $qo->fraction = array();
        $qo->tolerance = array();
        foreach ($answers as $answer) {
            // answer outside of <text> is deprecated
            $answertext = trim( $this->getpath( $answer, array('#',0), '' ) );
            $qo->answer[] = $this->getpath( $answer, array('#','text',0,'#'), $answertext, true );
            if (empty($qo->answer)) {
                $qo->answer = '*';
            }
            $qo->feedback[] = $this->getpath( $answer, array('#','feedback',0,'#','text',0,'#'), '', true );