4ddff96d502f5dab47db1001ace74a4d55cd78cb
[moodle.git] / question / format / xml / format.php
1 <?php
2 // This file is part of Moodle - http://moodle.org/
3 //
4 // Moodle is free software: you can redistribute it and/or modify
5 // it under the terms of the GNU General Public License as published by
6 // the Free Software Foundation, either version 3 of the License, or
7 // (at your option) any later version.
8 //
9 // Moodle is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 // GNU General Public License for more details.
13 //
14 // You should have received a copy of the GNU General Public License
15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
17 /**
18  * Code for exporting questions as Moodle XML.
19  *
20  * @package    qformat_xml
21  * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}
22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
23  */
26 defined('MOODLE_INTERNAL') || die();
28 require_once($CFG->libdir . '/xmlize.php');
29 if (!class_exists('qformat_default')) {
30     // This is ugly, but this class is also (ab)used by mod/lesson, which defines
31     // a different base class in mod/lesson/format.php. Thefore, we can only
32     // include the proper base class conditionally like this. (We have to include
33     // the base class like this, otherwise it breaks third-party question types.)
34     // This may be reviewd, and a better fix found one day.
35     require_once($CFG->dirroot . '/question/format.php');
36 }
39 /**
40  * Importer for Moodle XML question format.
41  *
42  * See http://docs.moodle.org/en/Moodle_XML_format for a description of the format.
43  *
44  * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}
45  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
46  */
47 class qformat_xml extends qformat_default {
49     public function provide_import() {
50         return true;
51     }
53     public function provide_export() {
54         return true;
55     }
57     public function mime_type() {
58         return 'application/xml';
59     }
61     // IMPORT FUNCTIONS START HERE.
63     /**
64      * Translate human readable format name
65      * into internal Moodle code number
66      * @param string name format name from xml file
67      * @return int Moodle format code
68      */
69     public function trans_format($name) {
70         $name = trim($name);
72         if ($name == 'moodle_auto_format') {
73             return FORMAT_MOODLE;
74         } else if ($name == 'html') {
75             return FORMAT_HTML;
76         } else if ($name == 'plain_text') {
77             return FORMAT_PLAIN;
78         } else if ($name == 'wiki_like') {
79             return FORMAT_WIKI;
80         } else if ($name == 'markdown') {
81             return FORMAT_MARKDOWN;
82         } else {
83             debugging("Unrecognised text format '{$name}' in the import file. Assuming 'html'.");
84             return FORMAT_HTML;
85         }
86     }
88     /**
89      * Translate human readable single answer option
90      * to internal code number
91      * @param string name true/false
92      * @return int internal code number
93      */
94     public function trans_single($name) {
95         $name = trim($name);
96         if ($name == "false" || !$name) {
97             return 0;
98         } else {
99             return 1;
100         }
101     }
103     /**
104      * process text string from xml file
105      * @param array $text bit of xml tree after ['text']
106      * @return string processed text.
107      */
108     public function import_text($text) {
109         // Quick sanity check.
110         if (empty($text)) {
111             return '';
112         }
113         $data = $text[0]['#'];
114         return trim($data);
115     }
117     /**
118      * return the value of a node, given a path to the node
119      * if it doesn't exist return the default value
120      * @param array xml data to read
121      * @param array path path to node expressed as array
122      * @param mixed default
123      * @param bool istext process as text
124      * @param string error if set value must exist, return false and issue message if not
125      * @return mixed value
126      */
127     public function getpath($xml, $path, $default, $istext=false, $error='') {
128         foreach ($path as $index) {
129             if (!isset($xml[$index])) {
130                 if (!empty($error)) {
131                     $this->error($error);
132                     return false;
133                 } else {
134                     return $default;
135                 }
136             }
138             $xml = $xml[$index];
139         }
141         if ($istext) {
142             if (!is_string($xml)) {
143                 $this->error(get_string('invalidxml', 'qformat_xml'));
144             }
145             $xml = trim($xml);
146         }
148         return $xml;
149     }
151     public function import_text_with_files($data, $path, $defaultvalue = '', $defaultformat = 'html') {
152         $field  = array();
153         $field['text'] = $this->getpath($data,
154                 array_merge($path, array('#', 'text', 0, '#')), $defaultvalue, true);
155         $field['format'] = $this->trans_format($this->getpath($data,
156                 array_merge($path, array('@', 'format')), $defaultformat));
157         $itemid = $this->import_files_as_draft($this->getpath($data,
158                 array_merge($path, array('#', 'file')), array(), false));
159         if (!empty($itemid)) {
160             $field['itemid'] = $itemid;
161         }
162         return $field;
163     }
165     public function import_files_as_draft($xml) {
166         global $USER;
167         if (empty($xml)) {
168             return null;
169         }
170         $fs = get_file_storage();
171         $itemid = file_get_unused_draft_itemid();
172         $filepaths = array();
173         foreach ($xml as $file) {
174             $filename = $this->getpath($file, array('@', 'name'), '', true);
175             $filepath = $this->getpath($file, array('@', 'path'), '/', true);
176             $fullpath = $filepath . $filename;
177             if (in_array($fullpath, $filepaths)) {
178                 debugging('Duplicate file in XML: ' . $fullpath, DEBUG_DEVELOPER);
179                 continue;
180             }
181             $filerecord = array(
182                 'contextid' => context_user::instance($USER->id)->id,
183                 'component' => 'user',
184                 'filearea'  => 'draft',
185                 'itemid'    => $itemid,
186                 'filepath'  => $filepath,
187                 'filename'  => $filename,
188             );
189             $fs->create_file_from_string($filerecord, base64_decode($file['#']));
190             $filepaths[] = $fullpath;
191         }
192         return $itemid;
193     }
195     /**
196      * import parts of question common to all types
197      * @param $question array question question array from xml tree
198      * @return object question object
199      */
200     public function import_headers($question) {
201         global $CFG, $USER;
203         // This routine initialises the question object.
204         $qo = $this->defaultquestion();
206         // Question name.
207         $qo->name = $this->clean_question_name($this->getpath($question,
208                 array('#', 'name', 0, '#', 'text', 0, '#'), '', true,
209                 get_string('xmlimportnoname', 'qformat_xml')));
210         $questiontext = $this->import_text_with_files($question,
211                 array('#', 'questiontext', 0));
212         $qo->questiontext = $questiontext['text'];
213         $qo->questiontextformat = $questiontext['format'];
214         if (!empty($questiontext['itemid'])) {
215             $qo->questiontextitemid = $questiontext['itemid'];
216         }
217         // Backwards compatibility, deal with the old image tag.
218         $filedata = $this->getpath($question, array('#', 'image_base64', '0', '#'), null, false);
219         $filename = $this->getpath($question, array('#', 'image', '0', '#'), null, false);
220         if ($filedata && $filename) {
221             $fs = get_file_storage();
222             if (empty($qo->questiontextitemid)) {
223                 $qo->questiontextitemid = file_get_unused_draft_itemid();
224             }
225             $filename = clean_param(str_replace('/', '_', $filename), PARAM_FILE);
226             $filerecord = array(
227                 'contextid' => context_user::instance($USER->id)->id,
228                 'component' => 'user',
229                 'filearea'  => 'draft',
230                 'itemid'    => $qo->questiontextitemid,
231                 'filepath'  => '/',
232                 'filename'  => $filename,
233             );
234             $fs->create_file_from_string($filerecord, base64_decode($filedata));
235             $qo->questiontext .= ' <img src="@@PLUGINFILE@@/' . $filename . '" />';
236         }
238         // Restore files in generalfeedback.
239         $generalfeedback = $this->import_text_with_files($question,
240                 array('#', 'generalfeedback', 0), $qo->generalfeedback, $this->get_format($qo->questiontextformat));
241         $qo->generalfeedback = $generalfeedback['text'];
242         $qo->generalfeedbackformat = $generalfeedback['format'];
243         if (!empty($generalfeedback['itemid'])) {
244             $qo->generalfeedbackitemid = $generalfeedback['itemid'];
245         }
247         $qo->defaultmark = $this->getpath($question,
248                 array('#', 'defaultgrade', 0, '#'), $qo->defaultmark);
249         $qo->penalty = $this->getpath($question,
250                 array('#', 'penalty', 0, '#'), $qo->penalty);
252         // Fix problematic rounding from old files.
253         if (abs($qo->penalty - 0.3333333) < 0.005) {
254             $qo->penalty = 0.3333333;
255         }
257         // Read the question tags.
258         if (!empty($CFG->usetags) && array_key_exists('tags', $question['#'])
259                 && !empty($question['#']['tags'][0]['#']['tag'])) {
260             require_once($CFG->dirroot.'/tag/lib.php');
261             $qo->tags = array();
262             foreach ($question['#']['tags'][0]['#']['tag'] as $tagdata) {
263                 $qo->tags[] = $this->getpath($tagdata, array('#', 'text', 0, '#'), '', true);
264             }
265         }
267         return $qo;
268     }
270     /**
271      * Import the common parts of a single answer
272      * @param array answer xml tree for single answer
273      * @param bool $withanswerfiles if true, the answers are HTML (or $defaultformat)
274      *      and so may contain files, otherwise the answers are plain text.
275      * @param array Default text format for the feedback, and the answers if $withanswerfiles
276      *      is true.
277      * @return object answer object
278      */
279     public function import_answer($answer, $withanswerfiles = false, $defaultformat = 'html') {
280         $ans = new stdClass();
282         if ($withanswerfiles) {
283             $ans->answer = $this->import_text_with_files($answer, array(), '', $defaultformat);
284         } else {
285             $ans->answer = array();
286             $ans->answer['text']   = $this->getpath($answer, array('#', 'text', 0, '#'), '', true);
287             $ans->answer['format'] = FORMAT_PLAIN;
288         }
290         $ans->feedback = $this->import_text_with_files($answer, array('#', 'feedback', 0), '', $defaultformat);
292         $ans->fraction = $this->getpath($answer, array('@', 'fraction'), 0) / 100;
294         return $ans;
295     }
297     /**
298      * Import the common overall feedback fields.
299      * @param object $question the part of the XML relating to this question.
300      * @param object $qo the question data to add the fields to.
301      * @param bool $withshownumpartscorrect include the shownumcorrect field.
302      */
303     public function import_combined_feedback($qo, $questionxml, $withshownumpartscorrect = false) {
304         $fields = array('correctfeedback', 'partiallycorrectfeedback', 'incorrectfeedback');
305         foreach ($fields as $field) {
306             $qo->$field = $this->import_text_with_files($questionxml,
307                     array('#', $field, 0), '', $this->get_format($qo->questiontextformat));
308         }
310         if ($withshownumpartscorrect) {
311             $qo->shownumcorrect = array_key_exists('shownumcorrect', $questionxml['#']);
313             // Backwards compatibility.
314             if (array_key_exists('correctresponsesfeedback', $questionxml['#'])) {
315                 $qo->shownumcorrect = $this->trans_single($this->getpath($questionxml,
316                         array('#', 'correctresponsesfeedback', 0, '#'), 1));
317             }
318         }
319     }
321     /**
322      * Import a question hint
323      * @param array $hintxml hint xml fragment.
324      * @param string $defaultformat the text format to assume for hints that do not specify.
325      * @return object hint for storing in the database.
326      */
327     public function import_hint($hintxml, $defaultformat) {
328         $hint = new stdClass();
329         if (array_key_exists('hintcontent', $hintxml['#'])) {
330             // Backwards compatibility.
332             $hint->hint = $this->import_text_with_files($hintxml,
333                     array('#', 'hintcontent', 0), '', $defaultformat);
335             $hint->shownumcorrect = $this->getpath($hintxml,
336                     array('#', 'statenumberofcorrectresponses', 0, '#'), 0);
337             $hint->clearwrong = $this->getpath($hintxml,
338                     array('#', 'clearincorrectresponses', 0, '#'), 0);
339             $hint->options = $this->getpath($hintxml,
340                     array('#', 'showfeedbacktoresponses', 0, '#'), 0);
342             return $hint;
343         }
344         $hint->hint = $this->import_text_with_files($hintxml, array(), '', $defaultformat);
345         $hint->shownumcorrect = array_key_exists('shownumcorrect', $hintxml['#']);
346         $hint->clearwrong = array_key_exists('clearwrong', $hintxml['#']);
347         $hint->options = $this->getpath($hintxml, array('#', 'options', 0, '#'), '', true);
349         return $hint;
350     }
352     /**
353      * Import all the question hints
354      *
355      * @param object $qo the question data that is being constructed.
356      * @param array $questionxml The xml representing the question.
357      * @param bool $withparts whether the extra fields relating to parts should be imported.
358      * @param bool $withoptions whether the extra options field should be imported.
359      * @param string $defaultformat the text format to assume for hints that do not specify.
360      * @return array of objects representing the hints in the file.
361      */
362     public function import_hints($qo, $questionxml, $withparts = false,
363             $withoptions = false, $defaultformat = 'html') {
364         if (!isset($questionxml['#']['hint'])) {
365             return;
366         }
368         foreach ($questionxml['#']['hint'] as $hintxml) {
369             $hint = $this->import_hint($hintxml, $defaultformat);
370             $qo->hint[] = $hint->hint;
372             if ($withparts) {
373                 $qo->hintshownumcorrect[] = $hint->shownumcorrect;
374                 $qo->hintclearwrong[] = $hint->clearwrong;
375             }
377             if ($withoptions) {
378                 $qo->hintoptions[] = $hint->options;
379             }
380         }
381     }
383     /**
384      * Import files from a node in the XML.
385      * @param array $xml an array of <file> nodes from the the parsed XML.
386      * @return array of things representing files - in the form that save_question expects.
387      */
388     public function import_files($xml) {
389         $files = array();
390         foreach ($xml as $file) {
391             $data = new stdClass();
392             $data->content = $file['#'];
393             $data->encoding = $file['@']['encoding'];
394             $data->name = $file['@']['name'];
395             $files[] = $data;
396         }
397         return $files;
398     }
400     /**
401      * import multiple choice question
402      * @param array question question array from xml tree
403      * @return object question object
404      */
405     public function import_multichoice($question) {
406         // Get common parts.
407         $qo = $this->import_headers($question);
409         // Header parts particular to multichoice.
410         $qo->qtype = 'multichoice';
411         $single = $this->getpath($question, array('#', 'single', 0, '#'), 'true');
412         $qo->single = $this->trans_single($single);
413         $shuffleanswers = $this->getpath($question,
414                 array('#', 'shuffleanswers', 0, '#'), 'false');
415         $qo->answernumbering = $this->getpath($question,
416                 array('#', 'answernumbering', 0, '#'), 'abc');
417         $qo->shuffleanswers = $this->trans_single($shuffleanswers);
419         // There was a time on the 1.8 branch when it could output an empty
420         // answernumbering tag, so fix up any found.
421         if (empty($qo->answernumbering)) {
422             $qo->answernumbering = 'abc';
423         }
425         // Run through the answers.
426         $answers = $question['#']['answer'];
427         $acount = 0;
428         foreach ($answers as $answer) {
429             $ans = $this->import_answer($answer, true, $this->get_format($qo->questiontextformat));
430             $qo->answer[$acount] = $ans->answer;
431             $qo->fraction[$acount] = $ans->fraction;
432             $qo->feedback[$acount] = $ans->feedback;
433             ++$acount;
434         }
436         $this->import_combined_feedback($qo, $question, true);
437         $this->import_hints($qo, $question, true, false, $this->get_format($qo->questiontextformat));
439         return $qo;
440     }
442     /**
443      * Import cloze type question
444      * @param array question question array from xml tree
445      * @return object question object
446      */
447     public function import_multianswer($question) {
448         global $USER;
449         question_bank::get_qtype('multianswer');
451         $questiontext = $this->import_text_with_files($question,
452                 array('#', 'questiontext', 0));
453         $qo = qtype_multianswer_extract_question($questiontext);
455         // Header parts particular to multianswer.
456         $qo->qtype = 'multianswer';
458         // Only set the course if the data is available.
459         if (isset($this->course)) {
460             $qo->course = $this->course;
461         }
463         $qo->name = $this->clean_question_name($this->import_text($question['#']['name'][0]['#']['text']));
464         $qo->questiontextformat = $questiontext['format'];
465         $qo->questiontext = $qo->questiontext['text'];
466         if (!empty($questiontext['itemid'])) {
467             $qo->questiontextitemid = $questiontext['itemid'];
468         }
470         // Backwards compatibility, deal with the old image tag.
471         $filedata = $this->getpath($question, array('#', 'image_base64', '0', '#'), null, false);
472         $filename = $this->getpath($question, array('#', 'image', '0', '#'), null, false);
473         if ($filedata && $filename) {
474             $fs = get_file_storage();
475             if (empty($qo->questiontextitemid)) {
476                 $qo->questiontextitemid = file_get_unused_draft_itemid();
477             }
478             $filename = clean_param(str_replace('/', '_', $filename), PARAM_FILE);
479             $filerecord = array(
480                 'contextid' => context_user::instance($USER->id)->id,
481                 'component' => 'user',
482                 'filearea'  => 'draft',
483                 'itemid'    => $qo->questiontextitemid,
484                 'filepath'  => '/',
485                 'filename'  => $filename,
486             );
487             $fs->create_file_from_string($filerecord, base64_decode($filedata));
488             $qo->questiontext .= ' <img src="@@PLUGINFILE@@/' . $filename . '" />';
489         }
491         // Restore files in generalfeedback.
492         $generalfeedback = $this->import_text_with_files($question,
493                 array('#', 'generalfeedback', 0), $qo->generalfeedback, $this->get_format($qo->questiontextformat));
494         $qo->generalfeedback = $generalfeedback['text'];
495         $qo->generalfeedbackformat = $generalfeedback['format'];
496         if (!empty($generalfeedback['itemid'])) {
497             $qo->generalfeedbackitemid = $generalfeedback['itemid'];
498         }
500         $qo->penalty = $this->getpath($question,
501                 array('#', 'penalty', 0, '#'), $this->defaultquestion()->penalty);
502         // Fix problematic rounding from old files.
503         if (abs($qo->penalty - 0.3333333) < 0.005) {
504             $qo->penalty = 0.3333333;
505         }
507         $this->import_hints($qo, $question, true, false, $this->get_format($qo->questiontextformat));
509         return $qo;
510     }
512     /**
513      * Import true/false type question
514      * @param array question question array from xml tree
515      * @return object question object
516      */
517     public function import_truefalse($question) {
518         // Get common parts.
519         global $OUTPUT;
520         $qo = $this->import_headers($question);
522         // Header parts particular to true/false.
523         $qo->qtype = 'truefalse';
525         // In the past, it used to be assumed that the two answers were in the file
526         // true first, then false. Howevever that was not always true. Now, we
527         // try to match on the answer text, but in old exports, this will be a localised
528         // string, so if we don't find true or false, we fall back to the old system.
529         $first = true;
530         $warning = false;
531         foreach ($question['#']['answer'] as $answer) {
532             $answertext = $this->getpath($answer,
533                     array('#', 'text', 0, '#'), '', true);
534             $feedback = $this->import_text_with_files($answer,
535                     array('#', 'feedback', 0), '', $this->get_format($qo->questiontextformat));
537             if ($answertext != 'true' && $answertext != 'false') {
538                 // Old style file, assume order is true/false.
539                 $warning = true;
540                 if ($first) {
541                     $answertext = 'true';
542                 } else {
543                     $answertext = 'false';
544                 }
545             }
547             if ($answertext == 'true') {
548                 $qo->answer = ($answer['@']['fraction'] == 100);
549                 $qo->correctanswer = $qo->answer;
550                 $qo->feedbacktrue = $feedback;
551             } else {
552                 $qo->answer = ($answer['@']['fraction'] != 100);
553                 $qo->correctanswer = $qo->answer;
554                 $qo->feedbackfalse = $feedback;
555             }
556             $first = false;
557         }
559         if ($warning) {
560             $a = new stdClass();
561             $a->questiontext = $qo->questiontext;
562             $a->answer = get_string($qo->correctanswer ? 'true' : 'false', 'qtype_truefalse');
563             echo $OUTPUT->notification(get_string('truefalseimporterror', 'qformat_xml', $a));
564         }
566         $this->import_hints($qo, $question, false, false, $this->get_format($qo->questiontextformat));
568         return $qo;
569     }
571     /**
572      * Import short answer type question
573      * @param array question question array from xml tree
574      * @return object question object
575      */
576     public function import_shortanswer($question) {
577         // Get common parts.
578         $qo = $this->import_headers($question);
580         // Header parts particular to shortanswer.
581         $qo->qtype = 'shortanswer';
583         // Get usecase.
584         $qo->usecase = $this->getpath($question, array('#', 'usecase', 0, '#'), $qo->usecase);
586         // Run through the answers.
587         $answers = $question['#']['answer'];
588         $acount = 0;
589         foreach ($answers as $answer) {
590             $ans = $this->import_answer($answer, false, $this->get_format($qo->questiontextformat));
591             $qo->answer[$acount] = $ans->answer['text'];
592             $qo->fraction[$acount] = $ans->fraction;
593             $qo->feedback[$acount] = $ans->feedback;
594             ++$acount;
595         }
597         $this->import_hints($qo, $question, false, false, $this->get_format($qo->questiontextformat));
599         return $qo;
600     }
602     /**
603      * Import description type question
604      * @param array question question array from xml tree
605      * @return object question object
606      */
607     public function import_description($question) {
608         // Get common parts.
609         $qo = $this->import_headers($question);
610         // Header parts particular to shortanswer.
611         $qo->qtype = 'description';
612         $qo->defaultmark = 0;
613         $qo->length = 0;
614         return $qo;
615     }
617     /**
618      * Import numerical type question
619      * @param array question question array from xml tree
620      * @return object question object
621      */
622     public function import_numerical($question) {
623         // Get common parts.
624         $qo = $this->import_headers($question);
626         // Header parts particular to numerical.
627         $qo->qtype = 'numerical';
629         // Get answers array.
630         $answers = $question['#']['answer'];
631         $qo->answer = array();
632         $qo->feedback = array();
633         $qo->fraction = array();
634         $qo->tolerance = array();
635         foreach ($answers as $answer) {
636             // Answer outside of <text> is deprecated.
637             $obj = $this->import_answer($answer, false, $this->get_format($qo->questiontextformat));
638             $qo->answer[] = $obj->answer['text'];
639             if (empty($qo->answer)) {
640                 $qo->answer = '*';
641             }
642             $qo->feedback[]  = $obj->feedback;
643             $qo->tolerance[] = $this->getpath($answer, array('#', 'tolerance', 0, '#'), 0);
645             // Fraction as a tag is deprecated.
646             $fraction = $this->getpath($answer, array('@', 'fraction'), 0) / 100;
647             $qo->fraction[] = $this->getpath($answer,
648                     array('#', 'fraction', 0, '#'), $fraction); // Deprecated.
649         }
651         // Get the units array.
652         $qo->unit = array();
653         $units = $this->getpath($question, array('#', 'units', 0, '#', 'unit'), array());
654         if (!empty($units)) {
655             $qo->multiplier = array();
656             foreach ($units as $unit) {
657                 $qo->multiplier[] = $this->getpath($unit, array('#', 'multiplier', 0, '#'), 1);
658                 $qo->unit[] = $this->getpath($unit, array('#', 'unit_name', 0, '#'), '', true);
659             }
660         }
661         $qo->unitgradingtype = $this->getpath($question, array('#', 'unitgradingtype', 0, '#'), 0);
662         $qo->unitpenalty = $this->getpath($question, array('#', 'unitpenalty', 0, '#'), 0.1);
663         $qo->showunits = $this->getpath($question, array('#', 'showunits', 0, '#'), null);
664         $qo->unitsleft = $this->getpath($question, array('#', 'unitsleft', 0, '#'), 0);
665         $qo->instructions['text'] = '';
666         $qo->instructions['format'] = FORMAT_HTML;
667         $instructions = $this->getpath($question, array('#', 'instructions'), array());
668         if (!empty($instructions)) {
669             $qo->instructions = $this->import_text_with_files($instructions,
670                     array('0'), '', $this->get_format($qo->questiontextformat));
671         }
673         if (is_null($qo->showunits)) {
674             // Set a good default, depending on whether there are any units defined.
675             if (empty($qo->unit)) {
676                 $qo->showunits = 3; // This is qtype_numerical::UNITNONE, but we cannot refer to that constant here.
677             } else {
678                 $qo->showunits = 0; // This is qtype_numerical::UNITOPTIONAL, but we cannot refer to that constant here.
679             }
680         }
682         $this->import_hints($qo, $question, false, false, $this->get_format($qo->questiontextformat));
684         return $qo;
685     }
687     /**
688      * Import matching type question
689      * @param array question question array from xml tree
690      * @return object question object
691      */
692     public function import_match($question) {
693         // Get common parts.
694         $qo = $this->import_headers($question);
696         // Header parts particular to matching.
697         $qo->qtype = 'match';
698         $qo->shuffleanswers = $this->trans_single($this->getpath($question,
699                 array('#', 'shuffleanswers', 0, '#'), 1));
701         // Run through subquestions.
702         $qo->subquestions = array();
703         $qo->subanswers = array();
704         foreach ($question['#']['subquestion'] as $subqxml) {
705             $qo->subquestions[] = $this->import_text_with_files($subqxml,
706                     array(), '', $this->get_format($qo->questiontextformat));
708             $answers = $this->getpath($subqxml, array('#', 'answer'), array());
709             $qo->subanswers[] = $this->getpath($subqxml,
710                     array('#', 'answer', 0, '#', 'text', 0, '#'), '', true);
711         }
713         $this->import_combined_feedback($qo, $question, true);
714         $this->import_hints($qo, $question, true, false, $this->get_format($qo->questiontextformat));
716         return $qo;
717     }
719     /**
720      * Import essay type question
721      * @param array question question array from xml tree
722      * @return object question object
723      */
724     public function import_essay($question) {
725         // Get common parts.
726         $qo = $this->import_headers($question);
728         // Header parts particular to essay.
729         $qo->qtype = 'essay';
731         $qo->responseformat = $this->getpath($question,
732                 array('#', 'responseformat', 0, '#'), 'editor');
733         $qo->responsefieldlines = $this->getpath($question,
734                 array('#', 'responsefieldlines', 0, '#'), 15);
735         $qo->responserequired = $this->getpath($question,
736                 array('#', 'responserequired', 0, '#'), 1);
737         $qo->attachments = $this->getpath($question,
738                 array('#', 'attachments', 0, '#'), 0);
739         $qo->attachmentsrequired = $this->getpath($question,
740                 array('#', 'attachmentsrequired', 0, '#'), 0);
741         $qo->graderinfo = $this->import_text_with_files($question,
742                 array('#', 'graderinfo', 0), '', $this->get_format($qo->questiontextformat));
743         $qo->responsetemplate['text'] = $this->getpath($question,
744                 array('#', 'responsetemplate', 0, '#', 'text', 0, '#'), '', true);
745         $qo->responsetemplate['format'] = $this->trans_format($this->getpath($question,
746                 array('#', 'responsetemplate', 0, '@', 'format'), $this->get_format($qo->questiontextformat)));
748         return $qo;
749     }
751     /**
752      * Import a calculated question
753      * @param object $question the imported XML data.
754      */
755     public function import_calculated($question) {
757         // Get common parts.
758         $qo = $this->import_headers($question);
760         // Header parts particular to calculated.
761         $qo->qtype = 'calculated';
762         $qo->synchronize = $this->getpath($question, array('#', 'synchronize', 0, '#'), 0);
763         $single = $this->getpath($question, array('#', 'single', 0, '#'), 'true');
764         $qo->single = $this->trans_single($single);
765         $shuffleanswers = $this->getpath($question, array('#', 'shuffleanswers', 0, '#'), 'false');
766         $qo->answernumbering = $this->getpath($question,
767                 array('#', 'answernumbering', 0, '#'), 'abc');
768         $qo->shuffleanswers = $this->trans_single($shuffleanswers);
770         $this->import_combined_feedback($qo, $question);
772         $qo->unitgradingtype = $this->getpath($question,
773                 array('#', 'unitgradingtype', 0, '#'), 0);
774         $qo->unitpenalty = $this->getpath($question, array('#', 'unitpenalty', 0, '#'), null);
775         $qo->showunits = $this->getpath($question, array('#', 'showunits', 0, '#'), 0);
776         $qo->unitsleft = $this->getpath($question, array('#', 'unitsleft', 0, '#'), 0);
777         $qo->instructions = $this->getpath($question,
778                 array('#', 'instructions', 0, '#', 'text', 0, '#'), '', true);
779         if (!empty($instructions)) {
780             $qo->instructions = $this->import_text_with_files($instructions,
781                     array('0'), '', $this->get_format($qo->questiontextformat));
782         }
784         // Get answers array.
785         $answers = $question['#']['answer'];
786         $qo->answer = array();
787         $qo->feedback = array();
788         $qo->fraction = array();
789         $qo->tolerance = array();
790         $qo->tolerancetype = array();
791         $qo->correctanswerformat = array();
792         $qo->correctanswerlength = array();
793         $qo->feedback = array();
794         foreach ($answers as $answer) {
795             $ans = $this->import_answer($answer, true, $this->get_format($qo->questiontextformat));
796             // Answer outside of <text> is deprecated.
797             if (empty($ans->answer['text'])) {
798                 $ans->answer['text'] = '*';
799             }
800             $qo->answer[] = $ans->answer['text'];
801             $qo->feedback[] = $ans->feedback;
802             $qo->tolerance[] = $answer['#']['tolerance'][0]['#'];
803             // Fraction as a tag is deprecated.
804             if (!empty($answer['#']['fraction'][0]['#'])) {
805                 $qo->fraction[] = $answer['#']['fraction'][0]['#'];
806             } else {
807                 $qo->fraction[] = $answer['@']['fraction'] / 100;
808             }
809             $qo->tolerancetype[] = $answer['#']['tolerancetype'][0]['#'];
810             $qo->correctanswerformat[] = $answer['#']['correctanswerformat'][0]['#'];
811             $qo->correctanswerlength[] = $answer['#']['correctanswerlength'][0]['#'];
812         }
813         // Get units array.
814         $qo->unit = array();
815         if (isset($question['#']['units'][0]['#']['unit'])) {
816             $units = $question['#']['units'][0]['#']['unit'];
817             $qo->multiplier = array();
818             foreach ($units as $unit) {
819                 $qo->multiplier[] = $unit['#']['multiplier'][0]['#'];
820                 $qo->unit[] = $unit['#']['unit_name'][0]['#'];
821             }
822         }
823         $instructions = $this->getpath($question, array('#', 'instructions'), array());
824         if (!empty($instructions)) {
825             $qo->instructions = $this->import_text_with_files($instructions,
826                     array('0'), '', $this->get_format($qo->questiontextformat));
827         }
829         if (is_null($qo->unitpenalty)) {
830             // Set a good default, depending on whether there are any units defined.
831             if (empty($qo->unit)) {
832                 $qo->showunits = 3; // This is qtype_numerical::UNITNONE, but we cannot refer to that constant here.
833             } else {
834                 $qo->showunits = 0; // This is qtype_numerical::UNITOPTIONAL, but we cannot refer to that constant here.
835             }
836         }
838         $datasets = $question['#']['dataset_definitions'][0]['#']['dataset_definition'];
839         $qo->dataset = array();
840         $qo->datasetindex= 0;
841         foreach ($datasets as $dataset) {
842             $qo->datasetindex++;
843             $qo->dataset[$qo->datasetindex] = new stdClass();
844             $qo->dataset[$qo->datasetindex]->status =
845                     $this->import_text($dataset['#']['status'][0]['#']['text']);
846             $qo->dataset[$qo->datasetindex]->name =
847                     $this->import_text($dataset['#']['name'][0]['#']['text']);
848             $qo->dataset[$qo->datasetindex]->type =
849                     $dataset['#']['type'][0]['#'];
850             $qo->dataset[$qo->datasetindex]->distribution =
851                     $this->import_text($dataset['#']['distribution'][0]['#']['text']);
852             $qo->dataset[$qo->datasetindex]->max =
853                     $this->import_text($dataset['#']['maximum'][0]['#']['text']);
854             $qo->dataset[$qo->datasetindex]->min =
855                     $this->import_text($dataset['#']['minimum'][0]['#']['text']);
856             $qo->dataset[$qo->datasetindex]->length =
857                     $this->import_text($dataset['#']['decimals'][0]['#']['text']);
858             $qo->dataset[$qo->datasetindex]->distribution =
859                     $this->import_text($dataset['#']['distribution'][0]['#']['text']);
860             $qo->dataset[$qo->datasetindex]->itemcount = $dataset['#']['itemcount'][0]['#'];
861             $qo->dataset[$qo->datasetindex]->datasetitem = array();
862             $qo->dataset[$qo->datasetindex]->itemindex = 0;
863             $qo->dataset[$qo->datasetindex]->number_of_items = $this->getpath($dataset,
864                     array('#', 'number_of_items', 0, '#'), 0);
865             $datasetitems = $this->getpath($dataset,
866                     array('#', 'dataset_items', 0, '#', 'dataset_item'), array());
867             foreach ($datasetitems as $datasetitem) {
868                 $qo->dataset[$qo->datasetindex]->itemindex++;
869                 $qo->dataset[$qo->datasetindex]->datasetitem[
870                         $qo->dataset[$qo->datasetindex]->itemindex] = new stdClass();
871                 $qo->dataset[$qo->datasetindex]->datasetitem[
872                         $qo->dataset[$qo->datasetindex]->itemindex]->itemnumber =
873                                 $datasetitem['#']['number'][0]['#'];
874                 $qo->dataset[$qo->datasetindex]->datasetitem[
875                         $qo->dataset[$qo->datasetindex]->itemindex]->value =
876                                 $datasetitem['#']['value'][0]['#'];
877             }
878         }
880         $this->import_hints($qo, $question, false, false, $this->get_format($qo->questiontextformat));
882         return $qo;
883     }
885     /**
886      * This is not a real question type. It's a dummy type used to specify the
887      * import category. The format is:
888      * <question type="category">
889      *     <category>tom/dick/harry</category>
890      * </question>
891      */
892     protected function import_category($question) {
893         $qo = new stdClass();
894         $qo->qtype = 'category';
895         $qo->category = $this->import_text($question['#']['category'][0]['#']['text']);
896         return $qo;
897     }
899     /**
900      * Parse the array of lines into an array of questions
901      * this *could* burn memory - but it won't happen that much
902      * so fingers crossed!
903      * @param array of lines from the input file.
904      * @param stdClass $context
905      * @return array (of objects) question objects.
906      */
907     protected function readquestions($lines) {
908         // We just need it as one big string.
909         $lines = implode('', $lines);
911         // This converts xml to big nasty data structure
912         // the 0 means keep white space as it is (important for markdown format).
913         try {
914             $xml = xmlize($lines, 0, 'UTF-8', true);
915         } catch (xml_format_exception $e) {
916             $this->error($e->getMessage(), '');
917             return false;
918         }
919         unset($lines); // No need to keep this in memory.
920         return $this->import_questions($xml['quiz']['#']['question']);
921     }
923     /**
924      * @param array $xml the xmlized xml
925      * @return stdClass[] question objects to pass to question type save_question_options
926      */
927     public function import_questions($xml) {
928         $questions = array();
930         // Iterate through questions.
931         foreach ($xml as $questionxml) {
932             $qo = $this->import_question($questionxml);
934             // Stick the result in the $questions array.
935             if ($qo) {
936                 $questions[] = $qo;
937             }
938         }
939         return $questions;
940     }
942     /**
943      * @param array $questionxml xml describing the question
944      * @return null|stdClass an object with data to be fed to question type save_question_options
945      */
946     protected function import_question($questionxml) {
947         $questiontype = $questionxml['@']['type'];
949         if ($questiontype == 'multichoice') {
950             return $this->import_multichoice($questionxml);
951         } else if ($questiontype == 'truefalse') {
952             return $this->import_truefalse($questionxml);
953         } else if ($questiontype == 'shortanswer') {
954             return $this->import_shortanswer($questionxml);
955         } else if ($questiontype == 'numerical') {
956             return $this->import_numerical($questionxml);
957         } else if ($questiontype == 'description') {
958             return $this->import_description($questionxml);
959         } else if ($questiontype == 'matching' || $questiontype == 'match') {
960             return $this->import_match($questionxml);
961         } else if ($questiontype == 'cloze' || $questiontype == 'multianswer') {
962             return $this->import_multianswer($questionxml);
963         } else if ($questiontype == 'essay') {
964             return $this->import_essay($questionxml);
965         } else if ($questiontype == 'calculated') {
966             return $this->import_calculated($questionxml);
967         } else if ($questiontype == 'calculatedsimple') {
968             $qo = $this->import_calculated($questionxml);
969             $qo->qtype = 'calculatedsimple';
970             return $qo;
971         } else if ($questiontype == 'calculatedmulti') {
972             $qo = $this->import_calculated($questionxml);
973             $qo->qtype = 'calculatedmulti';
974             return $qo;
975         } else if ($questiontype == 'category') {
976             return $this->import_category($questionxml);
978         } else {
979             // Not a type we handle ourselves. See if the question type wants
980             // to handle it.
981             if (!$qo = $this->try_importing_using_qtypes($questionxml, null, null, $questiontype)) {
982                 $this->error(get_string('xmltypeunsupported', 'qformat_xml', $questiontype));
983                 return null;
984             }
985             return $qo;
986         }
987     }
989     // EXPORT FUNCTIONS START HERE.
991     public function export_file_extension() {
992         return '.xml';
993     }
995     /**
996      * Turn the internal question type name into a human readable form.
997      * (In the past, the code used to use integers internally. Now, it uses
998      * strings, so there is less need for this, but to maintain
999      * backwards-compatibility we change two of the type names.)
1000      * @param string $qtype question type plugin name.
1001      * @return string $qtype string to use in the file.
1002      */
1003     protected function get_qtype($qtype) {
1004         switch($qtype) {
1005             case 'match':
1006                 return 'matching';
1007             case 'multianswer':
1008                 return 'cloze';
1009             default:
1010                 return $qtype;
1011         }
1012     }
1014     /**
1015      * Convert internal Moodle text format code into
1016      * human readable form
1017      * @param int id internal code
1018      * @return string format text
1019      */
1020     public function get_format($id) {
1021         switch($id) {
1022             case FORMAT_MOODLE:
1023                 return 'moodle_auto_format';
1024             case FORMAT_HTML:
1025                 return 'html';
1026             case FORMAT_PLAIN:
1027                 return 'plain_text';
1028             case FORMAT_WIKI:
1029                 return 'wiki_like';
1030             case FORMAT_MARKDOWN:
1031                 return 'markdown';
1032             default:
1033                 return 'unknown';
1034         }
1035     }
1037     /**
1038      * Convert internal single question code into
1039      * human readable form
1040      * @param int id single question code
1041      * @return string single question string
1042      */
1043     public function get_single($id) {
1044         switch($id) {
1045             case 0:
1046                 return 'false';
1047             case 1:
1048                 return 'true';
1049             default:
1050                 return 'unknown';
1051         }
1052     }
1054     /**
1055      * Take a string, and wrap it in a CDATA secion, if that is required to make
1056      * the output XML valid.
1057      * @param string $string a string
1058      * @return string the string, wrapped in CDATA if necessary.
1059      */
1060     public function xml_escape($string) {
1061         if (!empty($string) && htmlspecialchars($string) != $string) {
1062             // If the string contains something that looks like the end
1063             // of a CDATA section, then we need to avoid errors by splitting
1064             // the string between two CDATA sections.
1065             $string = str_replace(']]>', ']]]]><![CDATA[>', $string);
1066             return "<![CDATA[{$string}]]>";
1067         } else {
1068             return $string;
1069         }
1070     }
1072     /**
1073      * Generates <text></text> tags, processing raw text therein
1074      * @param string $raw the content to output.
1075      * @param int $indent the current indent level.
1076      * @param bool $short stick it on one line.
1077      * @return string formatted text.
1078      */
1079     public function writetext($raw, $indent = 0, $short = true) {
1080         $indent = str_repeat('  ', $indent);
1081         $raw = $this->xml_escape($raw);
1083         if ($short) {
1084             $xml = "{$indent}<text>{$raw}</text>\n";
1085         } else {
1086             $xml = "{$indent}<text>\n{$raw}\n{$indent}</text>\n";
1087         }
1089         return $xml;
1090     }
1092     /**
1093      * Generte the XML to represent some files.
1094      * @param array of store array of stored_file objects.
1095      * @return string $string the XML.
1096      */
1097     public function write_files($files) {
1098         if (empty($files)) {
1099             return '';
1100         }
1101         $string = '';
1102         foreach ($files as $file) {
1103             if ($file->is_directory()) {
1104                 continue;
1105             }
1106             $string .= '<file name="' . $file->get_filename() . '" path="' . $file->get_filepath() . '" encoding="base64">';
1107             $string .= base64_encode($file->get_content());
1108             $string .= "</file>\n";
1109         }
1110         return $string;
1111     }
1113     protected function presave_process($content) {
1114         // Override to allow us to add xml headers and footers.
1115         return '<?xml version="1.0" encoding="UTF-8"?>
1116 <quiz>
1117 ' . $content . '</quiz>';
1118     }
1120     /**
1121      * Turns question into an xml segment
1122      * @param object $question the question data.
1123      * @return string xml segment
1124      */
1125     public function writequestion($question) {
1126         global $CFG, $OUTPUT;
1128         $invalidquestion = false;
1129         $fs = get_file_storage();
1130         $contextid = $question->contextid;
1131         // Get files used by the questiontext.
1132         $question->questiontextfiles = $fs->get_area_files(
1133                 $contextid, 'question', 'questiontext', $question->id);
1134         // Get files used by the generalfeedback.
1135         $question->generalfeedbackfiles = $fs->get_area_files(
1136                 $contextid, 'question', 'generalfeedback', $question->id);
1137         if (!empty($question->options->answers)) {
1138             foreach ($question->options->answers as $answer) {
1139                 $answer->answerfiles = $fs->get_area_files(
1140                         $contextid, 'question', 'answer', $answer->id);
1141                 $answer->feedbackfiles = $fs->get_area_files(
1142                         $contextid, 'question', 'answerfeedback', $answer->id);
1143             }
1144         }
1146         $expout = '';
1148         // Add a comment linking this to the original question id.
1149         $expout .= "<!-- question: {$question->id}  -->\n";
1151         // Check question type.
1152         $questiontype = $this->get_qtype($question->qtype);
1154         // Categories are a special case.
1155         if ($question->qtype == 'category') {
1156             $categorypath = $this->writetext($question->category);
1157             $expout .= "  <question type=\"category\">\n";
1158             $expout .= "    <category>\n";
1159             $expout .= "        {$categorypath}\n";
1160             $expout .= "    </category>\n";
1161             $expout .= "  </question>\n";
1162             return $expout;
1163         }
1165         // Now we know we are are handing a real question.
1166         // Output the generic information.
1167         $expout .= "  <question type=\"{$questiontype}\">\n";
1168         $expout .= "    <name>\n";
1169         $expout .= $this->writetext($question->name, 3);
1170         $expout .= "    </name>\n";
1171         $expout .= "    <questiontext {$this->format($question->questiontextformat)}>\n";
1172         $expout .= $this->writetext($question->questiontext, 3);
1173         $expout .= $this->write_files($question->questiontextfiles);
1174         $expout .= "    </questiontext>\n";
1175         $expout .= "    <generalfeedback {$this->format($question->generalfeedbackformat)}>\n";
1176         $expout .= $this->writetext($question->generalfeedback, 3);
1177         $expout .= $this->write_files($question->generalfeedbackfiles);
1178         $expout .= "    </generalfeedback>\n";
1179         if ($question->qtype != 'multianswer') {
1180             $expout .= "    <defaultgrade>{$question->defaultmark}</defaultgrade>\n";
1181         }
1182         $expout .= "    <penalty>{$question->penalty}</penalty>\n";
1183         $expout .= "    <hidden>{$question->hidden}</hidden>\n";
1185         // The rest of the output depends on question type.
1186         switch($question->qtype) {
1187             case 'category':
1188                 // Not a qtype really - dummy used for category switching.
1189                 break;
1191             case 'truefalse':
1192                 $trueanswer = $question->options->answers[$question->options->trueanswer];
1193                 $trueanswer->answer = 'true';
1194                 $expout .= $this->write_answer($trueanswer);
1196                 $falseanswer = $question->options->answers[$question->options->falseanswer];
1197                 $falseanswer->answer = 'false';
1198                 $expout .= $this->write_answer($falseanswer);
1199                 break;
1201             case 'multichoice':
1202                 $expout .= "    <single>" . $this->get_single($question->options->single) .
1203                         "</single>\n";
1204                 $expout .= "    <shuffleanswers>" .
1205                         $this->get_single($question->options->shuffleanswers) .
1206                         "</shuffleanswers>\n";
1207                 $expout .= "    <answernumbering>" . $question->options->answernumbering .
1208                         "</answernumbering>\n";
1209                 $expout .= $this->write_combined_feedback($question->options, $question->id, $question->contextid);
1210                 $expout .= $this->write_answers($question->options->answers);
1211                 break;
1213             case 'shortanswer':
1214                 $expout .= "    <usecase>{$question->options->usecase}</usecase>\n";
1215                 $expout .= $this->write_answers($question->options->answers);
1216                 break;
1218             case 'numerical':
1219                 foreach ($question->options->answers as $answer) {
1220                     $expout .= $this->write_answer($answer,
1221                             "      <tolerance>{$answer->tolerance}</tolerance>\n");
1222                 }
1224                 $units = $question->options->units;
1225                 if (count($units)) {
1226                     $expout .= "<units>\n";
1227                     foreach ($units as $unit) {
1228                         $expout .= "  <unit>\n";
1229                         $expout .= "    <multiplier>{$unit->multiplier}</multiplier>\n";
1230                         $expout .= "    <unit_name>{$unit->unit}</unit_name>\n";
1231                         $expout .= "  </unit>\n";
1232                     }
1233                     $expout .= "</units>\n";
1234                 }
1235                 if (isset($question->options->unitgradingtype)) {
1236                     $expout .= "    <unitgradingtype>" . $question->options->unitgradingtype .
1237                             "</unitgradingtype>\n";
1238                 }
1239                 if (isset($question->options->unitpenalty)) {
1240                     $expout .= "    <unitpenalty>{$question->options->unitpenalty}</unitpenalty>\n";
1241                 }
1242                 if (isset($question->options->showunits)) {
1243                     $expout .= "    <showunits>{$question->options->showunits}</showunits>\n";
1244                 }
1245                 if (isset($question->options->unitsleft)) {
1246                     $expout .= "    <unitsleft>{$question->options->unitsleft}</unitsleft>\n";
1247                 }
1248                 if (!empty($question->options->instructionsformat)) {
1249                     $files = $fs->get_area_files($contextid, 'qtype_numerical',
1250                             'instruction', $question->id);
1251                     $expout .= "    <instructions " .
1252                             $this->format($question->options->instructionsformat) . ">\n";
1253                     $expout .= $this->writetext($question->options->instructions, 3);
1254                     $expout .= $this->write_files($files);
1255                     $expout .= "    </instructions>\n";
1256                 }
1257                 break;
1259             case 'match':
1260                 $expout .= "    <shuffleanswers>" .
1261                         $this->get_single($question->options->shuffleanswers) .
1262                         "</shuffleanswers>\n";
1263                 $expout .= $this->write_combined_feedback($question->options, $question->id, $question->contextid);
1264                 foreach ($question->options->subquestions as $subquestion) {
1265                     $files = $fs->get_area_files($contextid, 'qtype_match',
1266                             'subquestion', $subquestion->id);
1267                     $expout .= "    <subquestion " .
1268                             $this->format($subquestion->questiontextformat) . ">\n";
1269                     $expout .= $this->writetext($subquestion->questiontext, 3);
1270                     $expout .= $this->write_files($files);
1271                     $expout .= "      <answer>\n";
1272                     $expout .= $this->writetext($subquestion->answertext, 4);
1273                     $expout .= "      </answer>\n";
1274                     $expout .= "    </subquestion>\n";
1275                 }
1276                 break;
1278             case 'description':
1279                 // Nothing else to do.
1280                 break;
1282             case 'multianswer':
1283                 foreach ($question->options->questions as $index => $subq) {
1284                     $expout = str_replace('{#' . $index . '}', $subq->questiontext, $expout);
1285                 }
1286                 break;
1288             case 'essay':
1289                 $expout .= "    <responseformat>" . $question->options->responseformat .
1290                         "</responseformat>\n";
1291                 $expout .= "    <responserequired>" . $question->options->responserequired .
1292                         "</responserequired>\n";
1293                 $expout .= "    <responsefieldlines>" . $question->options->responsefieldlines .
1294                         "</responsefieldlines>\n";
1295                 $expout .= "    <attachments>" . $question->options->attachments .
1296                         "</attachments>\n";
1297                 $expout .= "    <attachmentsrequired>" . $question->options->attachmentsrequired .
1298                         "</attachmentsrequired>\n";
1299                 $expout .= "    <graderinfo " .
1300                         $this->format($question->options->graderinfoformat) . ">\n";
1301                 $expout .= $this->writetext($question->options->graderinfo, 3);
1302                 $expout .= $this->write_files($fs->get_area_files($contextid, 'qtype_essay',
1303                         'graderinfo', $question->id));
1304                 $expout .= "    </graderinfo>\n";
1305                 $expout .= "    <responsetemplate " .
1306                         $this->format($question->options->responsetemplateformat) . ">\n";
1307                 $expout .= $this->writetext($question->options->responsetemplate, 3);
1308                 $expout .= "    </responsetemplate>\n";
1309                 break;
1311             case 'calculated':
1312             case 'calculatedsimple':
1313             case 'calculatedmulti':
1314                 $expout .= "    <synchronize>{$question->options->synchronize}</synchronize>\n";
1315                 $expout .= "    <single>{$question->options->single}</single>\n";
1316                 $expout .= "    <answernumbering>" . $question->options->answernumbering .
1317                         "</answernumbering>\n";
1318                 $expout .= "    <shuffleanswers>" . $question->options->shuffleanswers .
1319                         "</shuffleanswers>\n";
1321                 $component = 'qtype_' . $question->qtype;
1322                 $files = $fs->get_area_files($contextid, $component,
1323                         'correctfeedback', $question->id);
1324                 $expout .= "    <correctfeedback>\n";
1325                 $expout .= $this->writetext($question->options->correctfeedback, 3);
1326                 $expout .= $this->write_files($files);
1327                 $expout .= "    </correctfeedback>\n";
1329                 $files = $fs->get_area_files($contextid, $component,
1330                         'partiallycorrectfeedback', $question->id);
1331                 $expout .= "    <partiallycorrectfeedback>\n";
1332                 $expout .= $this->writetext($question->options->partiallycorrectfeedback, 3);
1333                 $expout .= $this->write_files($files);
1334                 $expout .= "    </partiallycorrectfeedback>\n";
1336                 $files = $fs->get_area_files($contextid, $component,
1337                         'incorrectfeedback', $question->id);
1338                 $expout .= "    <incorrectfeedback>\n";
1339                 $expout .= $this->writetext($question->options->incorrectfeedback, 3);
1340                 $expout .= $this->write_files($files);
1341                 $expout .= "    </incorrectfeedback>\n";
1343                 foreach ($question->options->answers as $answer) {
1344                     $percent = 100 * $answer->fraction;
1345                     $expout .= "<answer fraction=\"{$percent}\">\n";
1346                     // The "<text/>" tags are an added feature, old files won't have them.
1347                     $expout .= "    <text>{$answer->answer}</text>\n";
1348                     $expout .= "    <tolerance>{$answer->tolerance}</tolerance>\n";
1349                     $expout .= "    <tolerancetype>{$answer->tolerancetype}</tolerancetype>\n";
1350                     $expout .= "    <correctanswerformat>" .
1351                             $answer->correctanswerformat . "</correctanswerformat>\n";
1352                     $expout .= "    <correctanswerlength>" .
1353                             $answer->correctanswerlength . "</correctanswerlength>\n";
1354                     $expout .= "    <feedback {$this->format($answer->feedbackformat)}>\n";
1355                     $files = $fs->get_area_files($contextid, $component,
1356                             'instruction', $question->id);
1357                     $expout .= $this->writetext($answer->feedback);
1358                     $expout .= $this->write_files($answer->feedbackfiles);
1359                     $expout .= "    </feedback>\n";
1360                     $expout .= "</answer>\n";
1361                 }
1362                 if (isset($question->options->unitgradingtype)) {
1363                     $expout .= "    <unitgradingtype>" .
1364                             $question->options->unitgradingtype . "</unitgradingtype>\n";
1365                 }
1366                 if (isset($question->options->unitpenalty)) {
1367                     $expout .= "    <unitpenalty>" .
1368                             $question->options->unitpenalty . "</unitpenalty>\n";
1369                 }
1370                 if (isset($question->options->showunits)) {
1371                     $expout .= "    <showunits>{$question->options->showunits}</showunits>\n";
1372                 }
1373                 if (isset($question->options->unitsleft)) {
1374                     $expout .= "    <unitsleft>{$question->options->unitsleft}</unitsleft>\n";
1375                 }
1377                 if (isset($question->options->instructionsformat)) {
1378                     $files = $fs->get_area_files($contextid, $component,
1379                             'instruction', $question->id);
1380                     $expout .= "    <instructions " .
1381                             $this->format($question->options->instructionsformat) . ">\n";
1382                     $expout .= $this->writetext($question->options->instructions, 3);
1383                     $expout .= $this->write_files($files);
1384                     $expout .= "    </instructions>\n";
1385                 }
1387                 if (isset($question->options->units)) {
1388                     $units = $question->options->units;
1389                     if (count($units)) {
1390                         $expout .= "<units>\n";
1391                         foreach ($units as $unit) {
1392                             $expout .= "  <unit>\n";
1393                             $expout .= "    <multiplier>{$unit->multiplier}</multiplier>\n";
1394                             $expout .= "    <unit_name>{$unit->unit}</unit_name>\n";
1395                             $expout .= "  </unit>\n";
1396                         }
1397                         $expout .= "</units>\n";
1398                     }
1399                 }
1401                 // The tag $question->export_process has been set so we get all the
1402                 // data items in the database from the function
1403                 // qtype_calculated::get_question_options calculatedsimple defaults
1404                 // to calculated.
1405                 if (isset($question->options->datasets) && count($question->options->datasets)) {
1406                     $expout .= "<dataset_definitions>\n";
1407                     foreach ($question->options->datasets as $def) {
1408                         $expout .= "<dataset_definition>\n";
1409                         $expout .= "    <status>".$this->writetext($def->status)."</status>\n";
1410                         $expout .= "    <name>".$this->writetext($def->name)."</name>\n";
1411                         if ($question->qtype == 'calculated') {
1412                             $expout .= "    <type>calculated</type>\n";
1413                         } else {
1414                             $expout .= "    <type>calculatedsimple</type>\n";
1415                         }
1416                         $expout .= "    <distribution>" . $this->writetext($def->distribution) .
1417                                 "</distribution>\n";
1418                         $expout .= "    <minimum>" . $this->writetext($def->minimum) .
1419                                 "</minimum>\n";
1420                         $expout .= "    <maximum>" . $this->writetext($def->maximum) .
1421                                 "</maximum>\n";
1422                         $expout .= "    <decimals>" . $this->writetext($def->decimals) .
1423                                 "</decimals>\n";
1424                         $expout .= "    <itemcount>{$def->itemcount}</itemcount>\n";
1425                         if ($def->itemcount > 0) {
1426                             $expout .= "    <dataset_items>\n";
1427                             foreach ($def->items as $item) {
1428                                   $expout .= "        <dataset_item>\n";
1429                                   $expout .= "           <number>".$item->itemnumber."</number>\n";
1430                                   $expout .= "           <value>".$item->value."</value>\n";
1431                                   $expout .= "        </dataset_item>\n";
1432                             }
1433                             $expout .= "    </dataset_items>\n";
1434                             $expout .= "    <number_of_items>" . $def->number_of_items .
1435                                     "</number_of_items>\n";
1436                         }
1437                         $expout .= "</dataset_definition>\n";
1438                     }
1439                     $expout .= "</dataset_definitions>\n";
1440                 }
1441                 break;
1443             default:
1444                 // Try support by optional plugin.
1445                 if (!$data = $this->try_exporting_using_qtypes($question->qtype, $question)) {
1446                     $invalidquestion = true;
1447                 } else {
1448                     $expout .= $data;
1449                 }
1450         }
1452         // Output any hints.
1453         $expout .= $this->write_hints($question);
1455         // Write the question tags.
1456         if (!empty($CFG->usetags)) {
1457             require_once($CFG->dirroot.'/tag/lib.php');
1458             $tags = tag_get_tags_array('question', $question->id);
1459             if (!empty($tags)) {
1460                 $expout .= "    <tags>\n";
1461                 foreach ($tags as $tag) {
1462                     $expout .= "      <tag>" . $this->writetext($tag, 0, true) . "</tag>\n";
1463                 }
1464                 $expout .= "    </tags>\n";
1465             }
1466         }
1468         // Close the question tag.
1469         $expout .= "  </question>\n";
1470         if ($invalidquestion) {
1471             return '';
1472         } else {
1473             return $expout;
1474         }
1475     }
1477     public function write_answers($answers) {
1478         if (empty($answers)) {
1479             return;
1480         }
1481         $output = '';
1482         foreach ($answers as $answer) {
1483             $output .= $this->write_answer($answer);
1484         }
1485         return $output;
1486     }
1488     public function write_answer($answer, $extra = '') {
1489         $percent = $answer->fraction * 100;
1490         $output = '';
1491         $output .= "    <answer fraction=\"{$percent}\" {$this->format($answer->answerformat)}>\n";
1492         $output .= $this->writetext($answer->answer, 3);
1493         $output .= $this->write_files($answer->answerfiles);
1494         $output .= "      <feedback {$this->format($answer->feedbackformat)}>\n";
1495         $output .= $this->writetext($answer->feedback, 4);
1496         $output .= $this->write_files($answer->feedbackfiles);
1497         $output .= "      </feedback>\n";
1498         $output .= $extra;
1499         $output .= "    </answer>\n";
1500         return $output;
1501     }
1503     /**
1504      * Write out the hints.
1505      * @param object $question the question definition data.
1506      * @return string XML to output.
1507      */
1508     public function write_hints($question) {
1509         if (empty($question->hints)) {
1510             return '';
1511         }
1513         $output = '';
1514         foreach ($question->hints as $hint) {
1515             $output .= $this->write_hint($hint, $question->contextid);
1516         }
1517         return $output;
1518     }
1520     /**
1521      * @param int $format a FORMAT_... constant.
1522      * @return string the attribute to add to an XML tag.
1523      */
1524     public function format($format) {
1525         return 'format="' . $this->get_format($format) . '"';
1526     }
1528     public function write_hint($hint, $contextid) {
1529         $fs = get_file_storage();
1530         $files = $fs->get_area_files($contextid, 'question', 'hint', $hint->id);
1532         $output = '';
1533         $output .= "    <hint {$this->format($hint->hintformat)}>\n";
1534         $output .= '      ' . $this->writetext($hint->hint);
1536         if (!empty($hint->shownumcorrect)) {
1537             $output .= "      <shownumcorrect/>\n";
1538         }
1539         if (!empty($hint->clearwrong)) {
1540             $output .= "      <clearwrong/>\n";
1541         }
1543         if (!empty($hint->options)) {
1544             $output .= '      <options>' . $this->xml_escape($hint->options) . "</options>\n";
1545         }
1546         $output .= $this->write_files($files);
1547         $output .= "    </hint>\n";
1548         return $output;
1549     }
1551     /**
1552      * Output the combined feedback fields.
1553      * @param object $questionoptions the question definition data.
1554      * @param int $questionid the question id.
1555      * @param int $contextid the question context id.
1556      * @return string XML to output.
1557      */
1558     public function write_combined_feedback($questionoptions, $questionid, $contextid) {
1559         $fs = get_file_storage();
1560         $output = '';
1562         $fields = array('correctfeedback', 'partiallycorrectfeedback', 'incorrectfeedback');
1563         foreach ($fields as $field) {
1564             $formatfield = $field . 'format';
1565             $files = $fs->get_area_files($contextid, 'question', $field, $questionid);
1567             $output .= "    <{$field} {$this->format($questionoptions->$formatfield)}>\n";
1568             $output .= '      ' . $this->writetext($questionoptions->$field);
1569             $output .= $this->write_files($files);
1570             $output .= "    </{$field}>\n";
1571         }
1573         if (!empty($questionoptions->shownumcorrect)) {
1574             $output .= "    <shownumcorrect/>\n";
1575         }
1576         return $output;
1577     }