on-demand release 2.8beta+
[moodle.git] / question / engine / questionattemptstep.php
CommitLineData
dcd03928 1<?php
dcd03928
TH
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/>.
16
17/**
18 * This file defines the question attempt step class, and a few related classes.
19 *
20 * @package moodlecore
21 * @subpackage questionengine
22 * @copyright 2009 The Open University
23 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
24 */
25
26
27defined('MOODLE_INTERNAL') || die();
28
29
30/**
31 * Stores one step in a {@link question_attempt}.
32 *
33 * The most important attributes of a step are the state, which is one of the
34 * {@link question_state} constants, the fraction, which may be null, or a
4e3d8293 35 * number bewteen the attempt's minfraction and maxfraction, and the array of submitted
dcd03928
TH
36 * data, about which more later.
37 *
38 * A step also tracks the time it was created, and the user responsible for
39 * creating it.
40 *
41 * The submitted data is basically just an array of name => value pairs, with
42 * certain conventions about the to divide the variables into four = two times two
43 * categories.
44 *
45 * Variables may either belong to the behaviour, in which case the
46 * name starts with a '-', or they may belong to the question type in which case
47 * they name does not start with a '-'.
48 *
49 * Second, variables may either be ones that came form the original request, in
50 * which case the name does not start with an _, or they are cached values that
51 * were created during processing, in which case the name does start with an _.
52 *
53 * That is, each name will start with one of '', '_'. '-' or '-_'. The remainder
54 * of the name should match the regex [a-z][a-z0-9]*.
55 *
56 * These variables can be accessed with {@link get_behaviour_var()} and {@link get_qt_var()},
57 * - to be clear, ->get_behaviour_var('x') gets the variable with name '-x' -
58 * and values whose names start with '_' can be set using {@link set_behaviour_var()}
59 * and {@link set_qt_var()}. There are some other methods like {@link has_behaviour_var()}
60 * to check wether a varaible with a particular name is set, and {@link get_behaviour_data()}
61 * to get all the behaviour data as an associative array.
62 *
63 * @copyright 2009 The Open University
64 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
65 */
66class question_attempt_step {
9c197f44
TH
67 /**
68 * @var integer if this attempts is stored in the question_attempts table,
69 * the id of that row.
70 */
dcd03928
TH
71 private $id = null;
72
9c197f44
TH
73 /**
74 * @var question_state one of the {@link question_state} constants.
75 * The state after this step.
76 */
dcd03928
TH
77 private $state;
78
4e3d8293
TH
79 /**
80 * @var null|number the fraction (grade on a scale of
81 * minfraction .. maxfraction, normally 0..1) or null.
82 */
dcd03928
TH
83 private $fraction = null;
84
85 /** @var integer the timestamp when this step was created. */
86 private $timecreated;
87
88 /** @var integer the id of the user resonsible for creating this step. */
89 private $userid;
90
91 /** @var array name => value pairs. The submitted data. */
92 private $data;
93
94 /** @var array name => array of {@link stored_file}s. Caches the contents of file areas. */
95 private $files = array();
96
97 /**
98 * You should not need to call this constructor in your own code. Steps are
99 * normally created by {@link question_attempt} methods like
100 * {@link question_attempt::process_action()}.
101 * @param array $data the submitted data that defines this step.
102 * @param int $timestamp the time to record for the action. (If not given, use now.)
103 * @param int $userid the user to attribute the aciton to. (If not given, use the current user.)
94815ccf
TH
104 * @param int $existingstepid if this step is going to replace an existing step
105 * (for example, during a regrade) this is the id of the previous step we are replacing.
dcd03928 106 */
94815ccf
TH
107 public function __construct($data = array(), $timecreated = null, $userid = null,
108 $existingstepid = null) {
dcd03928 109 global $USER;
36e91f1d 110
1da821bb 111 if (!is_array($data)) {
afb1b3d0 112 throw new coding_exception('$data must be an array when constructing a question_attempt_step.');
1da821bb 113 }
dcd03928
TH
114 $this->state = question_state::$unprocessed;
115 $this->data = $data;
116 if (is_null($timecreated)) {
117 $this->timecreated = time();
118 } else {
119 $this->timecreated = $timecreated;
120 }
121 if (is_null($userid)) {
122 $this->userid = $USER->id;
123 } else {
124 $this->userid = $userid;
125 }
94815ccf
TH
126
127 if (!is_null($existingstepid)) {
128 $this->id = $existingstepid;
129 }
130 }
131
132 /**
133 * @return int|null The id of this step in the database. null if this step
134 * is not stored in the database.
135 */
136 public function get_id() {
137 return $this->id;
dcd03928
TH
138 }
139
140 /** @return question_state The state after this step. */
141 public function get_state() {
142 return $this->state;
143 }
144
145 /**
146 * Set the state. Normally only called by behaviours.
147 * @param question_state $state one of the {@link question_state} constants.
148 */
149 public function set_state($state) {
150 $this->state = $state;
151 }
152
153 /**
4e3d8293
TH
154 * @return null|number the fraction (grade on a scale of
155 * minfraction .. maxfraction, normally 0..1),
dcd03928
TH
156 * or null if this step has not been marked.
157 */
158 public function get_fraction() {
159 return $this->fraction;
160 }
161
162 /**
163 * Set the fraction. Normally only called by behaviours.
164 * @param null|number $fraction the fraction to set.
165 */
166 public function set_fraction($fraction) {
167 $this->fraction = $fraction;
168 }
169
170 /** @return int the id of the user resonsible for creating this step. */
171 public function get_user_id() {
172 return $this->userid;
173 }
174
175 /** @return int the timestamp when this step was created. */
176 public function get_timecreated() {
177 return $this->timecreated;
178 }
179
180 /**
181 * @param string $name the name of a question type variable to look for in the submitted data.
182 * @return bool whether a variable with this name exists in the question type data.
183 */
184 public function has_qt_var($name) {
185 return array_key_exists($name, $this->data);
186 }
187
188 /**
189 * @param string $name the name of a question type variable to look for in the submitted data.
190 * @return string the requested variable, or null if the variable is not set.
191 */
192 public function get_qt_var($name) {
193 if (!$this->has_qt_var($name)) {
194 return null;
195 }
196 return $this->data[$name];
197 }
198
199 /**
200 * Set a cached question type variable.
201 * @param string $name the name of the variable to set. Must match _[a-z][a-z0-9]*.
202 * @param string $value the value to set.
203 */
204 public function set_qt_var($name, $value) {
205 if ($name[0] != '_') {
9c197f44
TH
206 throw new coding_exception('Cannot set question type data ' . $name .
207 ' on an attempt step. You can only set variables with names begining with _.');
dcd03928
TH
208 }
209 $this->data[$name] = $value;
210 }
211
212 /**
213 * Get the latest set of files for a particular question type variable of
214 * type question_attempt::PARAM_FILES.
215 *
216 * @param string $name the name of the associated variable.
217 * @return array of {@link stored_files}.
218 */
219 public function get_qt_files($name, $contextid) {
220 if (array_key_exists($name, $this->files)) {
221 return $this->files[$name];
222 }
223
224 if (!$this->has_qt_var($name)) {
225 $this->files[$name] = array();
226 return array();
227 }
228
229 $fs = get_file_storage();
230 $this->files[$name] = $fs->get_area_files($contextid, 'question',
231 'response_' . $name, $this->id, 'sortorder', false);
232
233 return $this->files[$name];
234 }
235
236 /**
237 * Prepare a draft file are for the files belonging the a response variable
238 * of this step.
239 *
240 * @param string $name the variable name the files belong to.
241 * @param int $contextid the id of the context the quba belongs to.
242 * @return int the draft itemid.
243 */
244 public function prepare_response_files_draft_itemid($name, $contextid) {
245 list($draftid, $notused) = $this->prepare_response_files_draft_itemid_with_text(
246 $name, $contextid, null);
247 return $draftid;
248 }
249
250 /**
251 * Prepare a draft file are for the files belonging the a response variable
252 * of this step, while rewriting the URLs in some text.
253 *
254 * @param string $name the variable name the files belong to.
255 * @param int $contextid the id of the context the quba belongs to.
256 * @param string $text the text to update the URLs in.
257 * @return array(int, string) the draft itemid and the text with URLs rewritten.
258 */
259 public function prepare_response_files_draft_itemid_with_text($name, $contextid, $text) {
260 $draftid = 0; // Will be filled in by file_prepare_draft_area.
261 $newtext = file_prepare_draft_area($draftid, $contextid, 'question',
262 'response_' . $name, $this->id, null, $text);
263 return array($draftid, $newtext);
264 }
265
266 /**
267 * Rewrite the @@PLUGINFILE@@ tokens in a response variable from this step
268 * that contains links to file. Normally you should probably call
269 * {@link question_attempt::rewrite_response_pluginfile_urls()} instead of
270 * calling this method directly.
271 *
272 * @param string $text the text to update the URLs in.
273 * @param int $contextid the id of the context the quba belongs to.
274 * @param string $name the variable name the files belong to.
275 * @param array $extra extra file path components.
276 * @return string the rewritten text.
277 */
278 public function rewrite_response_pluginfile_urls($text, $contextid, $name, $extras) {
279 return question_rewrite_question_urls($text, 'pluginfile.php', $contextid,
280 'question', 'response_' . $name, $extras, $this->id);
281 }
282
283 /**
284 * Get all the question type variables.
285 * @param array name => value pairs.
286 */
287 public function get_qt_data() {
288 $result = array();
289 foreach ($this->data as $name => $value) {
290 if ($name[0] != '-' && $name[0] != ':') {
291 $result[$name] = $value;
292 }
293 }
294 return $result;
295 }
296
297 /**
c4efeb2b 298 * @param string $name the name of a behaviour variable to look for in the submitted data.
dcd03928
TH
299 * @return bool whether a variable with this name exists in the question type data.
300 */
301 public function has_behaviour_var($name) {
302 return array_key_exists('-' . $name, $this->data);
303 }
304
305 /**
c4efeb2b 306 * @param string $name the name of a behaviour variable to look for in the submitted data.
dcd03928
TH
307 * @return string the requested variable, or null if the variable is not set.
308 */
309 public function get_behaviour_var($name) {
310 if (!$this->has_behaviour_var($name)) {
311 return null;
312 }
313 return $this->data['-' . $name];
314 }
315
316 /**
317 * Set a cached behaviour variable.
318 * @param string $name the name of the variable to set. Must match _[a-z][a-z0-9]*.
319 * @param string $value the value to set.
320 */
321 public function set_behaviour_var($name, $value) {
322 if ($name[0] != '_') {
9c197f44
TH
323 throw new coding_exception('Cannot set question type data ' . $name .
324 ' on an attempt step. You can only set variables with names begining with _.');
dcd03928
TH
325 }
326 return $this->data['-' . $name] = $value;
327 }
328
329 /**
330 * Get all the behaviour variables.
331 * @param array name => value pairs.
332 */
333 public function get_behaviour_data() {
334 $result = array();
335 foreach ($this->data as $name => $value) {
336 if ($name[0] == '-') {
337 $result[substr($name, 1)] = $value;
338 }
339 }
340 return $result;
341 }
342
343 /**
344 * Get all the submitted data, but not the cached data. behaviour
345 * variables have the - at the start of their name. This is only really
346 * intended for use by {@link question_attempt::regrade()}, it should not
347 * be considered part of the public API.
348 * @param array name => value pairs.
349 */
350 public function get_submitted_data() {
351 $result = array();
352 foreach ($this->data as $name => $value) {
353 if ($name[0] == '_' || ($name[0] == '-' && $name[1] == '_')) {
354 continue;
355 }
356 $result[$name] = $value;
357 }
358 return $result;
359 }
360
361 /**
362 * Get all the data. behaviour variables have the - at the start of
363 * their name. This is only intended for internal use, for example by
364 * {@link question_engine_data_mapper::insert_question_attempt_step()},
4040e2dd 365 * however, it can occasionally be useful in test code. It should not be
dcd03928
TH
366 * considered part of the public API of this class.
367 * @param array name => value pairs.
368 */
369 public function get_all_data() {
370 return $this->data;
371 }
372
373 /**
374 * Create a question_attempt_step from records loaded from the database.
35d5f1c2 375 * @param Iterator $records Raw records loaded from the database.
dcd03928 376 * @param int $stepid The id of the records to extract.
dc1ee5cb
TH
377 * @param string $qtype The question type of which this is an attempt.
378 * If not given, each record must include a qtype field.
dcd03928
TH
379 * @return question_attempt_step The newly constructed question_attempt_step.
380 */
dc1ee5cb 381 public static function load_from_records($records, $attemptstepid, $qtype = null) {
35d5f1c2 382 $currentrec = $records->current();
dcd03928 383 while ($currentrec->attemptstepid != $attemptstepid) {
35d5f1c2
TH
384 $records->next();
385 if (!$records->valid()) {
9c197f44
TH
386 throw new coding_exception('Question attempt step ' . $attemptstepid .
387 ' not found in the database.');
dcd03928 388 }
35d5f1c2 389 $currentrec = $records->current();
dcd03928
TH
390 }
391
392 $record = $currentrec;
dc1ee5cb 393 $contextid = null;
dcd03928
TH
394 $data = array();
395 while ($currentrec && $currentrec->attemptstepid == $attemptstepid) {
65cf651f 396 if (!is_null($currentrec->name)) {
dcd03928
TH
397 $data[$currentrec->name] = $currentrec->value;
398 }
35d5f1c2
TH
399 $records->next();
400 if ($records->valid()) {
401 $currentrec = $records->current();
402 } else {
403 $currentrec = false;
404 }
dcd03928
TH
405 }
406
407 $step = new question_attempt_step_read_only($data, $record->timecreated, $record->userid);
408 $step->state = question_state::get($record->state);
409 $step->id = $record->attemptstepid;
410 if (!is_null($record->fraction)) {
411 $step->fraction = $record->fraction + 0;
412 }
8a1e7b77
TH
413
414 // This next chunk of code requires getting $contextid and $qtype here.
415 // Somehow, we need to get that information to this point by modifying
416 // all the paths by which this method can be called.
d0782585 417 // Can we only return files when it's possible? Should there be some kind of warning?
dc1ee5cb
TH
418 if (is_null($qtype)) {
419 $qtype = $record->qtype;
420 }
421 foreach (question_bank::get_qtype($qtype)->response_file_areas() as $area) {
422 if (empty($step->data[$area])) {
423 continue;
8a1e7b77 424 }
dc1ee5cb
TH
425
426 $step->data[$area] = new question_file_loader($step, $area, $step->data[$area], $record->contextid);
8a1e7b77
TH
427 }
428
dcd03928
TH
429 return $step;
430 }
431}
432
433
434/**
435 * A subclass with a bit of additional funcitonality, for pending steps.
436 *
437 * @copyright 2010 The Open University
438 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
439 */
440class question_attempt_pending_step extends question_attempt_step {
441 /** @var string . */
442 protected $newresponsesummary = null;
443
444 /**
445 * If as a result of processing this step, the response summary for the
446 * question attempt should changed, you should call this method to set the
447 * new summary.
448 * @param string $responsesummary the new response summary.
449 */
450 public function set_new_response_summary($responsesummary) {
451 $this->newresponsesummary = $responsesummary;
452 }
453
454 /** @return string the new response summary, if any. */
455 public function get_new_response_summary() {
456 return $this->newresponsesummary;
457 }
458
459 /** @return string whether this step changes the response summary. */
460 public function response_summary_changed() {
461 return !is_null($this->newresponsesummary);
462 }
463}
464
465
466/**
467 * A subclass of {@link question_attempt_step} that cannot be modified.
468 *
469 * @copyright 2009 The Open University
470 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
471 */
472class question_attempt_step_read_only extends question_attempt_step {
473 public function set_state($state) {
474 throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
475 }
476 public function set_fraction($fraction) {
477 throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
478 }
479 public function set_qt_var($name, $value) {
480 throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
481 }
482 public function set_behaviour_var($name, $value) {
483 throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
484 }
485}
486
487
488/**
489 * A null {@link question_attempt_step} returned from
490 * {@link question_attempt::get_last_step()} etc. when a an attempt has just been
491 * created and there is no acutal step.
492 *
493 * @copyright 2009 The Open University
494 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
495 */
496class question_null_step {
497 public function get_state() {
498 return question_state::$notstarted;
499 }
500
501 public function set_state($state) {
502 throw new coding_exception('This question has not been started.');
503 }
504
505 public function get_fraction() {
506 return null;
507 }
508}
ab50232b
TH
509
510
511/**
512 * This is an adapter class that wraps a {@link question_attempt_step} and
513 * modifies the get/set_*_data methods so that they operate only on the parts
514 * that belong to a particular subquestion, as indicated by an extra prefix.
515 *
516 * @copyright 2010 The Open University
517 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
518 */
519class question_attempt_step_subquestion_adapter extends question_attempt_step {
520 /** @var question_attempt_step the step we are wrapping. */
521 protected $realstep;
522 /** @var string the exta prefix on fields we work with. */
523 protected $extraprefix;
524
525 /**
526 * Constructor.
527 * @param question_attempt_step $realqas the step to wrap. (Can be null if you
528 * just want to call add/remove.prefix.)
529 * @param unknown_type $extraprefix the extra prefix that is used for date fields.
530 */
531 public function __construct($realqas, $extraprefix) {
532 $this->realqas = $realqas;
533 $this->extraprefix = $extraprefix;
534 }
535
536 /**
537 * Add the extra prefix to a field name.
538 * @param string $field the plain field name.
539 * @return string the field name with the extra bit of prefix added.
540 */
541 public function add_prefix($field) {
542 if (substr($field, 0, 2) === '!_') {
543 return '-_' . $this->extraprefix . substr($field, 2);
544 } else if (substr($field, 0, 1) === '-') {
545 return '-' . $this->extraprefix . substr($field, 1);
546 } else if (substr($field, 0, 1) === '_') {
547 return '_' . $this->extraprefix . substr($field, 1);
548 } else {
549 return $this->extraprefix . $field;
550 }
551 }
552
553 /**
554 * Remove the extra prefix from a field name if it is present.
555 * @param string $field the extended field name.
556 * @return string the field name with the extra bit of prefix removed, or
557 * null if the extre prefix was not present.
558 */
559 public function remove_prefix($field) {
03cefcc9 560 if (preg_match('~^(-?_?)' . preg_quote($this->extraprefix, '~') . '(.*)$~', $field, $matches)) {
ab50232b
TH
561 return $matches[1] . $matches[2];
562 } else {
563 return null;
564 }
565 }
566
567 /**
568 * Filter some data to keep only those entries where the key contains
36e91f1d 569 * extraprefix, and remove the extra prefix from the reutrned arrary.
ab50232b
TH
570 * @param array $data some of the data stored in this step.
571 * @return array the data with the keys ajusted using {@link remove_prefix()}.
572 */
573 public function filter_array($data) {
574 $result = array();
575 foreach ($data as $fullname => $value) {
576 if ($name = $this->remove_prefix($fullname)) {
577 $result[$name] = $value;
578 }
579 }
580 return $result;
581 }
582
583 public function get_state() {
584 return $this->realqas->get_state();
585 }
586
587 public function set_state($state) {
588 throw new coding_exception('Cannot modify a question_attempt_step_subquestion_adapter.');
589 }
590
591 public function get_fraction() {
592 return $this->realqas->get_fraction();
593 }
594
595 public function set_fraction($fraction) {
596 throw new coding_exception('Cannot modify a question_attempt_step_subquestion_adapter.');
597 }
598
599 public function get_user_id() {
600 return $this->realqas->get_user_id;
601 }
602
603 public function get_timecreated() {
604 return $this->realqas->get_timecreated();
605 }
606
607 public function has_qt_var($name) {
608 return $this->realqas->has_qt_var($this->add_prefix($name));
609 }
610
611 public function get_qt_var($name) {
612 return $this->realqas->get_qt_var($this->add_prefix($name));
613 }
614
615 public function set_qt_var($name, $value) {
616 return $this->realqas->set_qt_var($this->add_prefix($name), $value);
617 }
618
619 public function get_qt_data() {
620 return $this->filter_array($this->realqas->get_qt_data());
621 }
622
623 public function has_behaviour_var($name) {
624 return $this->realqas->has_im_var($this->add_prefix($name));
625 }
626
627 public function get_behaviour_var($name) {
628 return $this->realqas->get_im_var($this->add_prefix($name));
629 }
630
631 public function set_behaviour_var($name, $value) {
632 return $this->realqas->set_im_var($this->add_prefix($name), $value);
633 }
634
635 public function get_behaviour_data() {
636 return $this->filter_array($this->realqas->get_behaviour_data());
637 }
638
639 public function get_submitted_data() {
640 return $this->filter_array($this->realqas->get_submitted_data());
641 }
642
643 public function get_all_data() {
644 return $this->filter_array($this->realqas->get_all_data());
645 }
646
647 public function get_qt_files($name, $contextid) {
648 throw new coding_exception('No attempt has yet been made to implement files support in ' .
649 'question_attempt_step_subquestion_adapter.');
650 }
651
652 public function prepare_response_files_draft_itemid($name, $contextid) {
653 throw new coding_exception('No attempt has yet been made to implement files support in ' .
654 'question_attempt_step_subquestion_adapter.');
655 }
656
657 public function prepare_response_files_draft_itemid_with_text($name, $contextid, $text) {
658 throw new coding_exception('No attempt has yet been made to implement files support in ' .
659 'question_attempt_step_subquestion_adapter.');
660 }
661
662 public function rewrite_response_pluginfile_urls($text, $contextid, $name, $extras) {
663 throw new coding_exception('No attempt has yet been made to implement files support in ' .
664 'question_attempt_step_subquestion_adapter.');
665 }
666}