MDL-40992 qbehaviour: new type method, can Qs can finish naturally
[moodle.git] / question / engine / questionattempt.php
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dcd03928 1<?php
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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 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 * Tracks an attempt at one particular question in a {@link question_usage_by_activity}.
32 *
33 * Most calling code should need to access objects of this class. They should be
34 * able to do everything through the usage interface. This class is an internal
35 * implementation detail of the question engine.
36 *
37 * Instances of this class correspond to rows in the question_attempts table, and
38 * a collection of {@link question_attempt_steps}. Question inteaction models and
39 * question types do work with question_attempt objects.
40 *
41 * @copyright 2009 The Open University
42 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
43 */
44class question_attempt {
45 /**
46 * @var string this is a magic value that question types can return from
47 * {@link question_definition::get_expected_data()}.
48 */
49 const USE_RAW_DATA = 'use raw data';
50
51 /**
61cca0b7 52 * @var string special value used by manual grading because {@link PARAM_FLOAT}
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53 * converts '' to 0.
54 */
55 const PARAM_MARK = 'parammark';
56
57 /**
58 * @var string special value to indicate a response variable that is uploaded
59 * files.
60 */
61 const PARAM_FILES = 'paramfiles';
62
63 /**
64 * @var string special value to indicate a response variable that is uploaded
65 * files.
66 */
2d2018ab 67 const PARAM_RAW_FILES = 'paramrawfiles';
dcd03928 68
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69 /**
70 * @var string means first try at a question during an attempt by a user.
71 */
72 const FIRST_TRY = 'firsttry';
73
74 /**
75 * @var string means last try at a question during an attempt by a user.
76 */
77 const LAST_TRY = 'lasttry';
78
79 /**
80 * @var string means all tries at a question during an attempt by a user.
81 */
82 const ALL_TRIES = 'alltries';
83
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84 /** @var integer if this attempts is stored in the question_attempts table, the id of that row. */
85 protected $id = null;
86
87 /** @var integer|string the id of the question_usage_by_activity we belong to. */
88 protected $usageid;
89
90 /** @var integer the number used to identify this question_attempt within the usage. */
91 protected $slot = null;
92
93 /**
94 * @var question_behaviour the behaviour controlling this attempt.
95 * null until {@link start()} is called.
96 */
97 protected $behaviour = null;
98
99 /** @var question_definition the question this is an attempt at. */
100 protected $question;
101
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102 /** @var int which variant of the question to use. */
103 protected $variant;
104
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105 /**
106 * @var float the maximum mark that can be scored at this question.
107 * Actually, this is only really a nominal maximum. It might be better thought
108 * of as the question weight.
109 */
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110 protected $maxmark;
111
112 /**
4e3d8293 113 * @var float the minimum fraction that can be scored at this question, so
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114 * the minimum mark is $this->minfraction * $this->maxmark.
115 */
116 protected $minfraction = null;
117
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118 /**
119 * @var float the maximum fraction that can be scored at this question, so
120 * the maximum mark is $this->maxfraction * $this->maxmark.
121 */
122 protected $maxfraction = null;
123
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124 /**
125 * @var string plain text summary of the variant of the question the
126 * student saw. Intended for reporting purposes.
127 */
128 protected $questionsummary = null;
129
130 /**
131 * @var string plain text summary of the response the student gave.
132 * Intended for reporting purposes.
133 */
134 protected $responsesummary = null;
135
136 /**
137 * @var string plain text summary of the correct response to this question
138 * variant the student saw. The format should be similar to responsesummary.
139 * Intended for reporting purposes.
140 */
141 protected $rightanswer = null;
142
143 /** @var array of {@link question_attempt_step}s. The steps in this attempt. */
144 protected $steps = array();
145
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146 /**
147 * @var question_attempt_step if, when we loaded the step from the DB, there was
148 * an autosaved step, we save a pointer to it here. (It is also added to the $steps array.)
149 */
150 protected $autosavedstep = null;
151
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152 /** @var boolean whether the user has flagged this attempt within the usage. */
153 protected $flagged = false;
154
155 /** @var question_usage_observer tracks changes to the useage this attempt is part of.*/
156 protected $observer;
157
158 /**#@+
159 * Constants used by the intereaction models to indicate whether the current
160 * pending step should be kept or discarded.
161 */
162 const KEEP = true;
163 const DISCARD = false;
164 /**#@-*/
165
166 /**
167 * Create a new {@link question_attempt}. Normally you should create question_attempts
168 * indirectly, by calling {@link question_usage_by_activity::add_question()}.
169 *
170 * @param question_definition $question the question this is an attempt at.
171 * @param int|string $usageid The id of the
172 * {@link question_usage_by_activity} we belong to. Used by {@link get_field_prefix()}.
173 * @param question_usage_observer $observer tracks changes to the useage this
174 * attempt is part of. (Optional, a {@link question_usage_null_observer} is
175 * used if one is not passed.
176 * @param number $maxmark the maximum grade for this question_attempt. If not
177 * passed, $question->defaultmark is used.
178 */
179 public function __construct(question_definition $question, $usageid,
180 question_usage_observer $observer = null, $maxmark = null) {
181 $this->question = $question;
182 $this->usageid = $usageid;
183 if (is_null($observer)) {
184 $observer = new question_usage_null_observer();
185 }
186 $this->observer = $observer;
187 if (!is_null($maxmark)) {
188 $this->maxmark = $maxmark;
189 } else {
190 $this->maxmark = $question->defaultmark;
191 }
192 }
193
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194 /**
195 * This method exists so that {@link question_attempt_with_restricted_history}
196 * can override it. You should not normally need to call it.
197 * @return question_attempt return ourself.
198 */
199 public function get_full_qa() {
200 return $this;
201 }
202
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203 /** @return question_definition the question this is an attempt at. */
204 public function get_question() {
205 return $this->question;
206 }
207
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208 /**
209 * Get the variant of the question being used in a given slot.
210 * @return int the variant number.
211 */
212 public function get_variant() {
213 return $this->variant;
214 }
215
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216 /**
217 * Set the number used to identify this question_attempt within the usage.
218 * For internal use only.
219 * @param int $slot
220 */
94815ccf 221 public function set_slot($slot) {
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222 $this->slot = $slot;
223 }
224
225 /** @return int the number used to identify this question_attempt within the usage. */
226 public function get_slot() {
227 return $this->slot;
228 }
229
230 /**
231 * @return int the id of row for this question_attempt, if it is stored in the
232 * database. null if not.
233 */
234 public function get_database_id() {
235 return $this->id;
236 }
237
238 /**
239 * For internal use only. Set the id of the corresponding database row.
240 * @param int $id the id of row for this question_attempt, if it is
241 * stored in the database.
242 */
243 public function set_database_id($id) {
244 $this->id = $id;
245 }
246
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247 /**
248 * You should almost certainly not call this method from your code. It is for
249 * internal use only.
250 * @param question_usage_observer that should be used to tracking changes made to this qa.
251 */
252 public function set_observer($observer) {
253 $this->observer = $observer;
254 }
255
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256 /** @return int|string the id of the {@link question_usage_by_activity} we belong to. */
257 public function get_usage_id() {
258 return $this->usageid;
259 }
260
261 /**
262 * Set the id of the {@link question_usage_by_activity} we belong to.
263 * For internal use only.
264 * @param int|string the new id.
265 */
266 public function set_usage_id($usageid) {
267 $this->usageid = $usageid;
268 }
269
270 /** @return string the name of the behaviour that is controlling this attempt. */
271 public function get_behaviour_name() {
272 return $this->behaviour->get_name();
273 }
274
275 /**
276 * For internal use only.
277 * @return question_behaviour the behaviour that is controlling this attempt.
278 */
279 public function get_behaviour() {
280 return $this->behaviour;
281 }
282
283 /**
284 * Set the flagged state of this question.
285 * @param bool $flagged the new state.
286 */
287 public function set_flagged($flagged) {
288 $this->flagged = $flagged;
289 $this->observer->notify_attempt_modified($this);
290 }
291
292 /** @return bool whether this question is currently flagged. */
293 public function is_flagged() {
294 return $this->flagged;
295 }
296
297 /**
298 * Get the name (in the sense a HTML name="" attribute, or a $_POST variable
299 * name) to use for the field that indicates whether this question is flagged.
300 *
301 * @return string The field name to use.
302 */
303 public function get_flag_field_name() {
304 return $this->get_control_field_name('flagged');
305 }
306
307 /**
308 * Get the name (in the sense a HTML name="" attribute, or a $_POST variable
309 * name) to use for a question_type variable belonging to this question_attempt.
310 *
311 * See the comment on {@link question_attempt_step} for an explanation of
312 * question type and behaviour variables.
313 *
314 * @param $varname The short form of the variable name.
315 * @return string The field name to use.
316 */
317 public function get_qt_field_name($varname) {
318 return $this->get_field_prefix() . $varname;
319 }
320
321 /**
322 * Get the name (in the sense a HTML name="" attribute, or a $_POST variable
323 * name) to use for a question_type variable belonging to this question_attempt.
324 *
325 * See the comment on {@link question_attempt_step} for an explanation of
326 * question type and behaviour variables.
327 *
328 * @param $varname The short form of the variable name.
329 * @return string The field name to use.
330 */
331 public function get_behaviour_field_name($varname) {
332 return $this->get_field_prefix() . '-' . $varname;
333 }
334
335 /**
336 * Get the name (in the sense a HTML name="" attribute, or a $_POST variable
337 * name) to use for a control variables belonging to this question_attempt.
338 *
339 * Examples are :sequencecheck and :flagged
340 *
341 * @param $varname The short form of the variable name.
342 * @return string The field name to use.
343 */
344 public function get_control_field_name($varname) {
345 return $this->get_field_prefix() . ':' . $varname;
346 }
347
348 /**
349 * Get the prefix added to variable names to give field names for this
350 * question attempt.
351 *
352 * You should not use this method directly. This is an implementation detail
353 * anyway, but if you must access it, use {@link question_usage_by_activity::get_field_prefix()}.
354 *
355 * @param $varname The short form of the variable name.
356 * @return string The field name to use.
357 */
358 public function get_field_prefix() {
359 return 'q' . $this->usageid . ':' . $this->slot . '_';
360 }
361
362 /**
363 * Get one of the steps in this attempt.
99caa248 364 *
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365 * @param int $i the step number.
366 * @return question_attempt_step
367 */
368 public function get_step($i) {
369 if ($i < 0 || $i >= count($this->steps)) {
370 throw new coding_exception('Index out of bounds in question_attempt::get_step.');
371 }
372 return $this->steps[$i];
373 }
374
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375 /**
376 * Get the number of real steps in this attempt.
377 * This is put as a hidden field in the HTML, so that when we receive some
378 * data to process, then we can check that it came from the question
379 * in the state we are now it.
380 * @return int a number that summarises the current state of this question attempt.
381 */
382 public function get_sequence_check_count() {
383 $numrealsteps = $this->get_num_steps();
384 if ($this->has_autosaved_step()) {
385 $numrealsteps -= 1;
386 }
387 return $numrealsteps;
388 }
389
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390 /**
391 * Get the number of steps in this attempt.
392 * For internal/test code use only.
393 * @return int the number of steps we currently have.
394 */
395 public function get_num_steps() {
396 return count($this->steps);
397 }
398
399 /**
400 * Return the latest step in this question_attempt.
401 * For internal/test code use only.
402 * @return question_attempt_step
403 */
404 public function get_last_step() {
405 if (count($this->steps) == 0) {
406 return new question_null_step();
407 }
408 return end($this->steps);
409 }
410
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411 /**
412 * @return boolean whether this question_attempt has autosaved data from
413 * some time in the past.
414 */
415 public function has_autosaved_step() {
416 return !is_null($this->autosavedstep);
417 }
418
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419 /**
420 * @return question_attempt_step_iterator for iterating over the steps in
421 * this attempt, in order.
422 */
423 public function get_step_iterator() {
424 return new question_attempt_step_iterator($this);
425 }
426
427 /**
428 * The same as {@link get_step_iterator()}. However, for a
429 * {@link question_attempt_with_restricted_history} this returns the full
430 * list of steps, while {@link get_step_iterator()} returns only the
431 * limited history.
432 * @return question_attempt_step_iterator for iterating over the steps in
433 * this attempt, in order.
434 */
435 public function get_full_step_iterator() {
436 return $this->get_step_iterator();
437 }
438
439 /**
440 * @return question_attempt_reverse_step_iterator for iterating over the steps in
441 * this attempt, in reverse order.
442 */
443 public function get_reverse_step_iterator() {
444 return new question_attempt_reverse_step_iterator($this);
445 }
446
447 /**
448 * Get the qt data from the latest step that has any qt data. Return $default
449 * array if it is no step has qt data.
450 *
451 * @param string $name the name of the variable to get.
452 * @param mixed default the value to return no step has qt data.
453 * (Optional, defaults to an empty array.)
454 * @return array|mixed the data, or $default if there is not any.
455 */
456 public function get_last_qt_data($default = array()) {
457 foreach ($this->get_reverse_step_iterator() as $step) {
458 $response = $step->get_qt_data();
459 if (!empty($response)) {
460 return $response;
461 }
462 }
463 return $default;
464 }
465
466 /**
467 * Get the last step with a particular question type varialbe set.
468 * @param string $name the name of the variable to get.
469 * @return question_attempt_step the last step, or a step with no variables
470 * if there was not a real step.
471 */
472 public function get_last_step_with_qt_var($name) {
473 foreach ($this->get_reverse_step_iterator() as $step) {
474 if ($step->has_qt_var($name)) {
475 return $step;
476 }
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477 }
478 return new question_attempt_step_read_only();
479 }
480
481 /**
482 * Get the last step with a particular behaviour variable set.
483 * @param string $name the name of the variable to get.
484 * @return question_attempt_step the last step, or a step with no variables
485 * if there was not a real step.
486 */
487 public function get_last_step_with_behaviour_var($name) {
488 foreach ($this->get_reverse_step_iterator() as $step) {
489 if ($step->has_behaviour_var($name)) {
490 return $step;
491 }
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492 }
493 return new question_attempt_step_read_only();
494 }
495
496 /**
497 * Get the latest value of a particular question type variable. That is, get
498 * the value from the latest step that has it set. Return null if it is not
499 * set in any step.
500 *
501 * @param string $name the name of the variable to get.
502 * @param mixed default the value to return in the variable has never been set.
503 * (Optional, defaults to null.)
504 * @return mixed string value, or $default if it has never been set.
505 */
506 public function get_last_qt_var($name, $default = null) {
507 $step = $this->get_last_step_with_qt_var($name);
508 if ($step->has_qt_var($name)) {
509 return $step->get_qt_var($name);
510 } else {
511 return $default;
512 }
513 }
514
515 /**
516 * Get the latest set of files for a particular question type variable of
517 * type question_attempt::PARAM_FILES.
518 *
519 * @param string $name the name of the associated variable.
520 * @return array of {@link stored_files}.
521 */
522 public function get_last_qt_files($name, $contextid) {
523 foreach ($this->get_reverse_step_iterator() as $step) {
524 if ($step->has_qt_var($name)) {
525 return $step->get_qt_files($name, $contextid);
526 }
527 }
528 return array();
529 }
530
531 /**
532 * Get the URL of a file that belongs to a response variable of this
533 * question_attempt.
534 * @param stored_file $file the file to link to.
535 * @return string the URL of that file.
536 */
537 public function get_response_file_url(stored_file $file) {
538 return file_encode_url(new moodle_url('/pluginfile.php'), '/' . implode('/', array(
539 $file->get_contextid(),
540 $file->get_component(),
541 $file->get_filearea(),
542 $this->usageid,
543 $this->slot,
544 $file->get_itemid())) .
545 $file->get_filepath() . $file->get_filename(), true);
546 }
547
548 /**
549 * Prepare a draft file are for the files belonging the a response variable
550 * of this question attempt. The draft area is populated with the files from
551 * the most recent step having files.
552 *
553 * @param string $name the variable name the files belong to.
554 * @param int $contextid the id of the context the quba belongs to.
555 * @return int the draft itemid.
556 */
557 public function prepare_response_files_draft_itemid($name, $contextid) {
558 foreach ($this->get_reverse_step_iterator() as $step) {
559 if ($step->has_qt_var($name)) {
560 return $step->prepare_response_files_draft_itemid($name, $contextid);
561 }
562 }
563
564 // No files yet.
565 $draftid = 0; // Will be filled in by file_prepare_draft_area.
566 file_prepare_draft_area($draftid, $contextid, 'question', 'response_' . $name, null);
567 return $draftid;
568 }
569
570 /**
571 * Get the latest value of a particular behaviour variable. That is,
572 * get the value from the latest step that has it set. Return null if it is
573 * not set in any step.
574 *
575 * @param string $name the name of the variable to get.
576 * @param mixed default the value to return in the variable has never been set.
577 * (Optional, defaults to null.)
578 * @return mixed string value, or $default if it has never been set.
579 */
580 public function get_last_behaviour_var($name, $default = null) {
581 foreach ($this->get_reverse_step_iterator() as $step) {
582 if ($step->has_behaviour_var($name)) {
583 return $step->get_behaviour_var($name);
584 }
585 }
586 return $default;
587 }
588
589 /**
590 * Get the current state of this question attempt. That is, the state of the
591 * latest step.
592 * @return question_state
593 */
594 public function get_state() {
595 return $this->get_last_step()->get_state();
596 }
597
598 /**
599 * @param bool $showcorrectness Whether right/partial/wrong states should
600 * be distinguised.
601 * @return string A brief textual description of the current state.
602 */
603 public function get_state_string($showcorrectness) {
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604 // Special case when attempt is based on previous one, see MDL-31226.
605 if ($this->get_num_steps() == 1 && $this->get_state() == question_state::$complete) {
606 return get_string('notchanged', 'question');
607 }
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608 return $this->behaviour->get_state_string($showcorrectness);
609 }
610
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611 /**
612 * @param bool $showcorrectness Whether right/partial/wrong states should
613 * be distinguised.
614 * @return string a CSS class name for the current state.
615 */
616 public function get_state_class($showcorrectness) {
617 return $this->get_state()->get_state_class($showcorrectness);
618 }
619
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620 /**
621 * @return int the timestamp of the most recent step in this question attempt.
622 */
623 public function get_last_action_time() {
624 return $this->get_last_step()->get_timecreated();
625 }
626
627 /**
628 * Get the current fraction of this question attempt. That is, the fraction
629 * of the latest step, or null if this question has not yet been graded.
630 * @return number the current fraction.
631 */
632 public function get_fraction() {
633 return $this->get_last_step()->get_fraction();
634 }
635
636 /** @return bool whether this question attempt has a non-zero maximum mark. */
637 public function has_marks() {
638 // Since grades are stored in the database as NUMBER(12,7).
639 return $this->maxmark >= 0.00000005;
640 }
641
642 /**
643 * @return number the current mark for this question.
644 * {@link get_fraction()} * {@link get_max_mark()}.
645 */
646 public function get_mark() {
647 return $this->fraction_to_mark($this->get_fraction());
648 }
649
650 /**
651 * This is used by the manual grading code, particularly in association with
652 * validation. If there is a mark submitted in the request, then use that,
653 * otherwise use the latest mark for this question.
654 * @return number the current mark for this question.
655 * {@link get_fraction()} * {@link get_max_mark()}.
656 */
657 public function get_current_manual_mark() {
658 $mark = $this->get_submitted_var($this->get_behaviour_field_name('mark'), question_attempt::PARAM_MARK);
659 if (is_null($mark)) {
660 return $this->get_mark();
661 } else {
662 return $mark;
663 }
664 }
665
666 /**
667 * @param number|null $fraction a fraction.
668 * @return number|null the corresponding mark.
669 */
670 public function fraction_to_mark($fraction) {
671 if (is_null($fraction)) {
672 return null;
673 }
674 return $fraction * $this->maxmark;
675 }
676
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677 /**
678 * @return float the maximum mark possible for this question attempt.
679 * In fact, this is not strictly the maximum, becuase get_max_fraction may
680 * return a number greater than 1. It might be better to think of this as a
681 * question weight.
682 */
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683 public function get_max_mark() {
684 return $this->maxmark;
685 }
686
4e3d8293 687 /** @return float the maximum mark possible for this question attempt. */
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688 public function get_min_fraction() {
689 if (is_null($this->minfraction)) {
4e3d8293 690 throw new coding_exception('This question_attempt has not been started yet, the min fraction is not yet known.');
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691 }
692 return $this->minfraction;
693 }
694
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695 /** @return float the maximum mark possible for this question attempt. */
696 public function get_max_fraction() {
697 if (is_null($this->maxfraction)) {
698 throw new coding_exception('This question_attempt has not been started yet, the max fraction is not yet known.');
699 }
700 return $this->maxfraction;
701 }
702
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703 /**
704 * The current mark, formatted to the stated number of decimal places. Uses
705 * {@link format_float()} to format floats according to the current locale.
706 * @param int $dp number of decimal places.
707 * @return string formatted mark.
708 */
709 public function format_mark($dp) {
710 return $this->format_fraction_as_mark($this->get_fraction(), $dp);
711 }
712
713 /**
714 * The current mark, formatted to the stated number of decimal places. Uses
715 * {@link format_float()} to format floats according to the current locale.
716 * @param int $dp number of decimal places.
717 * @return string formatted mark.
718 */
719 public function format_fraction_as_mark($fraction, $dp) {
720 return format_float($this->fraction_to_mark($fraction), $dp);
721 }
722
723 /**
724 * The maximum mark for this question attempt, formatted to the stated number
725 * of decimal places. Uses {@link format_float()} to format floats according
726 * to the current locale.
727 * @param int $dp number of decimal places.
728 * @return string formatted maximum mark.
729 */
730 public function format_max_mark($dp) {
731 return format_float($this->maxmark, $dp);
732 }
733
734 /**
735 * Return the hint that applies to the question in its current state, or null.
736 * @return question_hint|null
737 */
738 public function get_applicable_hint() {
739 return $this->behaviour->get_applicable_hint();
740 }
741
742 /**
743 * Produce a plain-text summary of what the user did during a step.
744 * @param question_attempt_step $step the step in quetsion.
745 * @return string a summary of what was done during that step.
746 */
747 public function summarise_action(question_attempt_step $step) {
748 return $this->behaviour->summarise_action($step);
749 }
750
751 /**
752 * Helper function used by {@link rewrite_pluginfile_urls()} and
753 * {@link rewrite_response_pluginfile_urls()}.
754 * @return array ids that need to go into the file paths.
755 */
756 protected function extra_file_path_components() {
757 return array($this->get_usage_id(), $this->get_slot());
758 }
759
760 /**
761 * Calls {@link question_rewrite_question_urls()} with appropriate parameters
762 * for content belonging to this question.
763 * @param string $text the content to output.
764 * @param string $component the component name (normally 'question' or 'qtype_...')
765 * @param string $filearea the name of the file area.
766 * @param int $itemid the item id.
767 * @return srting the content with the URLs rewritten.
768 */
769 public function rewrite_pluginfile_urls($text, $component, $filearea, $itemid) {
770 return question_rewrite_question_urls($text, 'pluginfile.php',
771 $this->question->contextid, $component, $filearea,
772 $this->extra_file_path_components(), $itemid);
773 }
774
775 /**
776 * Calls {@link question_rewrite_question_urls()} with appropriate parameters
777 * for content belonging to responses to this question.
778 *
779 * @param string $text the text to update the URLs in.
780 * @param int $contextid the id of the context the quba belongs to.
781 * @param string $name the variable name the files belong to.
782 * @param question_attempt_step $step the step the response is coming from.
783 * @return srting the content with the URLs rewritten.
784 */
785 public function rewrite_response_pluginfile_urls($text, $contextid, $name,
786 question_attempt_step $step) {
787 return $step->rewrite_response_pluginfile_urls($text, $contextid, $name,
788 $this->extra_file_path_components());
789 }
790
791 /**
792 * Get the {@link core_question_renderer}, in collaboration with appropriate
793 * {@link qbehaviour_renderer} and {@link qtype_renderer} subclasses, to generate the
794 * HTML to display this question attempt in its current state.
795 * @param question_display_options $options controls how the question is rendered.
796 * @param string|null $number The question number to display.
797 * @return string HTML fragment representing the question.
798 */
799 public function render($options, $number, $page = null) {
800 if (is_null($page)) {
801 global $PAGE;
802 $page = $PAGE;
803 }
804 $qoutput = $page->get_renderer('core', 'question');
805 $qtoutput = $this->question->get_renderer($page);
806 return $this->behaviour->render($options, $number, $qoutput, $qtoutput);
807 }
808
809 /**
810 * Generate any bits of HTML that needs to go in the <head> tag when this question
811 * attempt is displayed in the body.
812 * @return string HTML fragment.
813 */
814 public function render_head_html($page = null) {
815 if (is_null($page)) {
816 global $PAGE;
817 $page = $PAGE;
818 }
819 // TODO go via behaviour.
820 return $this->question->get_renderer($page)->head_code($this) .
821 $this->behaviour->get_renderer($page)->head_code($this);
822 }
823
824 /**
825 * Like {@link render_question()} but displays the question at the past step
826 * indicated by $seq, rather than showing the latest step.
827 *
828 * @param int $seq the seq number of the past state to display.
829 * @param question_display_options $options controls how the question is rendered.
830 * @param string|null $number The question number to display. 'i' is a special
831 * value that gets displayed as Information. Null means no number is displayed.
832 * @return string HTML fragment representing the question.
833 */
834 public function render_at_step($seq, $options, $number, $preferredbehaviour) {
835 $restrictedqa = new question_attempt_with_restricted_history($this, $seq, $preferredbehaviour);
836 return $restrictedqa->render($options, $number);
837 }
838
839 /**
840 * Checks whether the users is allow to be served a particular file.
841 * @param question_display_options $options the options that control display of the question.
842 * @param string $component the name of the component we are serving files for.
843 * @param string $filearea the name of the file area.
844 * @param array $args the remaining bits of the file path.
845 * @param bool $forcedownload whether the user must be forced to download the file.
846 * @return bool true if the user can access this file.
847 */
848 public function check_file_access($options, $component, $filearea, $args, $forcedownload) {
849 return $this->behaviour->check_file_access($options, $component, $filearea, $args, $forcedownload);
850 }
851
852 /**
853 * Add a step to this question attempt.
854 * @param question_attempt_step $step the new step.
855 */
856 protected function add_step(question_attempt_step $step) {
857 $this->steps[] = $step;
858 end($this->steps);
859 $this->observer->notify_step_added($step, $this, key($this->steps));
860 }
861
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862 /**
863 * Add an auto-saved step to this question attempt. We mark auto-saved steps by
864 * changing saving the step number with a - sign.
865 * @param question_attempt_step $step the new step.
866 */
867 protected function add_autosaved_step(question_attempt_step $step) {
868 $this->steps[] = $step;
869 $this->autosavedstep = $step;
870 end($this->steps);
871 $this->observer->notify_step_added($step, $this, -key($this->steps));
872 }
873
874 /**
875 * Discard any auto-saved data belonging to this question attempt.
876 */
877 public function discard_autosaved_step() {
878 if (!$this->has_autosaved_step()) {
879 return;
880 }
881
882 $autosaved = array_pop($this->steps);
883 $this->autosavedstep = null;
884 $this->observer->notify_step_deleted($autosaved, $this);
885 }
886
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887 /**
888 * If there is an autosaved step, convert it into a real save, so that it
889 * is preserved.
890 */
891 protected function convert_autosaved_step_to_real_step() {
892 if ($this->autosavedstep === null) {
893 return;
894 }
895
896 $laststep = end($this->steps);
897 if ($laststep !== $this->autosavedstep) {
898 throw new coding_exception('Cannot convert autosaved step to real step, since other steps have been added.');
899 }
900
901 $this->observer->notify_step_modified($this->autosavedstep, $this, key($this->steps));
902 $this->autosavedstep = null;
903 }
904
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905 /**
906 * Use a strategy to pick a variant.
907 * @param question_variant_selection_strategy $variantstrategy a strategy.
908 * @return int the selected variant.
909 */
910 public function select_variant(question_variant_selection_strategy $variantstrategy) {
911 return $variantstrategy->choose_variant($this->get_question()->get_num_variants(),
912 $this->get_question()->get_variants_selection_seed());
913 }
914
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915 /**
916 * Start this question attempt.
917 *
918 * You should not call this method directly. Call
919 * {@link question_usage_by_activity::start_question()} instead.
920 *
921 * @param string|question_behaviour $preferredbehaviour the name of the
922 * desired archetypal behaviour, or an actual model instance.
1da821bb
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923 * @param int $variant the variant of the question to start. Between 1 and
924 * $this->get_question()->get_num_variants() inclusive.
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925 * @param array $submitteddata optional, used when re-starting to keep the same initial state.
926 * @param int $timestamp optional, the timstamp to record for this action. Defaults to now.
927 * @param int $userid optional, the user to attribute this action to. Defaults to the current user.
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928 * @param int $existingstepid optional, if this step is going to replace an existing step
929 * (for example, during a regrade) this is the id of the previous step we are replacing.
dcd03928 930 */
1da821bb 931 public function start($preferredbehaviour, $variant, $submitteddata = array(),
94815ccf 932 $timestamp = null, $userid = null, $existingstepid = null) {
1da821bb 933
dcd03928 934 // Initialise the behaviour.
1da821bb 935 $this->variant = $variant;
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936 if (is_string($preferredbehaviour)) {
937 $this->behaviour =
938 $this->question->make_behaviour($this, $preferredbehaviour);
939 } else {
940 $class = get_class($preferredbehaviour);
941 $this->behaviour = new $class($this, $preferredbehaviour);
942 }
943
4e3d8293 944 // Record the minimum and maximum fractions.
dcd03928 945 $this->minfraction = $this->behaviour->get_min_fraction();
4e3d8293 946 $this->maxfraction = $this->behaviour->get_max_fraction();
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947
948 // Initialise the first step.
94815ccf 949 $firststep = new question_attempt_step($submitteddata, $timestamp, $userid, $existingstepid);
dcd03928 950 if ($submitteddata) {
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951 $firststep->set_state(question_state::$complete);
952 $this->behaviour->apply_attempt_state($firststep);
dcd03928 953 } else {
1da821bb 954 $this->behaviour->init_first_step($firststep, $variant);
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955 }
956 $this->add_step($firststep);
957
958 // Record questionline and correct answer.
959 $this->questionsummary = $this->behaviour->get_question_summary();
960 $this->rightanswer = $this->behaviour->get_right_answer_summary();
961 }
962
963 /**
964 * Start this question attempt, starting from the point that the previous
965 * attempt $oldqa had reached.
966 *
967 * You should not call this method directly. Call
968 * {@link question_usage_by_activity::start_question_based_on()} instead.
969 *
970 * @param question_attempt $oldqa a previous attempt at this quetsion that
971 * defines the starting point.
972 */
973 public function start_based_on(question_attempt $oldqa) {
1da821bb 974 $this->start($oldqa->behaviour, $oldqa->get_variant(), $oldqa->get_resume_data());
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975 }
976
977 /**
978 * Used by {@link start_based_on()} to get the data needed to start a new
979 * attempt from the point this attempt has go to.
980 * @return array name => value pairs.
981 */
982 protected function get_resume_data() {
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983 $resumedata = $this->behaviour->get_resume_data();
984 foreach ($resumedata as $name => $value) {
985 if ($value instanceof question_file_loader) {
986 $resumedata[$name] = $value->get_question_file_saver();
987 }
988 }
989 return $resumedata;
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990 }
991
992 /**
993 * Get a particular parameter from the current request. A wrapper round
994 * {@link optional_param()}, except that the results is returned without
995 * slashes.
996 * @param string $name the paramter name.
997 * @param int $type one of the standard PARAM_... constants, or one of the
998 * special extra constands defined by this class.
999 * @param array $postdata (optional, only inteded for testing use) take the
1000 * data from this array, instead of from $_POST.
1001 * @return mixed the requested value.
1002 */
1003 public function get_submitted_var($name, $type, $postdata = null) {
1004 switch ($type) {
1005 case self::PARAM_MARK:
61cca0b7 1006 // Special case to work around PARAM_FLOAT converting '' to 0.
2c76c894 1007 return question_utils::clean_param_mark($this->get_submitted_var($name, PARAM_RAW_TRIMMED, $postdata));
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1008
1009 case self::PARAM_FILES:
1010 return $this->process_response_files($name, $name, $postdata);
1011
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1012 case self::PARAM_RAW_FILES:
1013 $var = $this->get_submitted_var($name, PARAM_RAW, $postdata);
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1014 return $this->process_response_files($name, $name . ':itemid', $postdata, $var);
1015
1016 default:
1017 if (is_null($postdata)) {
1018 $var = optional_param($name, null, $type);
1019 } else if (array_key_exists($name, $postdata)) {
1020 $var = clean_param($postdata[$name], $type);
1021 } else {
1022 $var = null;
1023 }
1024
1025 return $var;
1026 }
1027 }
1028
1029 /**
1030 * Handle a submitted variable representing uploaded files.
1031 * @param string $name the field name.
1032 * @param string $draftidname the field name holding the draft file area id.
1033 * @param array $postdata (optional, only inteded for testing use) take the
1034 * data from this array, instead of from $_POST. At the moment, this
1035 * behaves as if there were no files.
1036 * @param string $text optional reponse text.
1037 * @return question_file_saver that can be used to save the files later.
1038 */
1039 protected function process_response_files($name, $draftidname, $postdata = null, $text = null) {
1040 if ($postdata) {
afb1b3d0
TH
1041 // For simulated posts, get the draft itemid from there.
1042 $draftitemid = $this->get_submitted_var($draftidname, PARAM_INT, $postdata);
1043 } else {
1044 $draftitemid = file_get_submitted_draft_itemid($draftidname);
dcd03928
TH
1045 }
1046
dcd03928
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1047 if (!$draftitemid) {
1048 return null;
1049 }
1050
1051 return new question_file_saver($draftitemid, 'question', 'response_' .
1052 str_replace($this->get_field_prefix(), '', $name), $text);
1053 }
1054
1055 /**
1056 * Get any data from the request that matches the list of expected params.
1057 * @param array $expected variable name => PARAM_... constant.
1058 * @param string $extraprefix '-' or ''.
1059 * @return array name => value.
1060 */
1061 protected function get_expected_data($expected, $postdata, $extraprefix) {
1062 $submitteddata = array();
1063 foreach ($expected as $name => $type) {
1064 $value = $this->get_submitted_var(
1065 $this->get_field_prefix() . $extraprefix . $name, $type, $postdata);
1066 if (!is_null($value)) {
1067 $submitteddata[$extraprefix . $name] = $value;
1068 }
1069 }
1070 return $submitteddata;
1071 }
1072
1073 /**
1074 * Get all the submitted question type data for this question, whithout checking
1075 * that it is valid or cleaning it in any way.
1076 * @return array name => value.
1077 */
df7d175d 1078 public function get_all_submitted_qt_vars($postdata) {
dcd03928
TH
1079 if (is_null($postdata)) {
1080 $postdata = $_POST;
1081 }
1082
03cefcc9 1083 $pattern = '/^' . preg_quote($this->get_field_prefix(), '/') . '[^-:]/';
dcd03928
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1084 $prefixlen = strlen($this->get_field_prefix());
1085
1086 $submitteddata = array();
df7d175d 1087 foreach ($postdata as $name => $value) {
dcd03928
TH
1088 if (preg_match($pattern, $name)) {
1089 $submitteddata[substr($name, $prefixlen)] = $value;
1090 }
1091 }
1092
1093 return $submitteddata;
1094 }
1095
1096 /**
1097 * Get all the sumbitted data belonging to this question attempt from the
1098 * current request.
1099 * @param array $postdata (optional, only inteded for testing use) take the
1100 * data from this array, instead of from $_POST.
1101 * @return array name => value pairs that could be passed to {@link process_action()}.
1102 */
1103 public function get_submitted_data($postdata = null) {
1104 $submitteddata = $this->get_expected_data(
1105 $this->behaviour->get_expected_data(), $postdata, '-');
1106
1107 $expected = $this->behaviour->get_expected_qt_data();
1108 if ($expected === self::USE_RAW_DATA) {
1109 $submitteddata += $this->get_all_submitted_qt_vars($postdata);
1110 } else {
1111 $submitteddata += $this->get_expected_data($expected, $postdata, '');
1112 }
1113 return $submitteddata;
1114 }
1115
1116 /**
1117 * Get a set of response data for this question attempt that would get the
da22c012
K
1118 * best possible mark. If it is not possible to compute a correct
1119 * response, this method should return null.
1120 * @return array|null name => value pairs that could be passed to {@link process_action()}.
dcd03928
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1121 */
1122 public function get_correct_response() {
1123 $response = $this->question->get_correct_response();
da22c012
K
1124 if (is_null($response)) {
1125 return null;
1126 }
dcd03928
TH
1127 $imvars = $this->behaviour->get_correct_response();
1128 foreach ($imvars as $name => $value) {
1129 $response['-' . $name] = $value;
1130 }
1131 return $response;
1132 }
1133
1134 /**
1135 * Change the quetsion summary. Note, that this is almost never necessary.
1136 * This method was only added to work around a limitation of the Opaque
1137 * protocol, which only sends questionLine at the end of an attempt.
1138 * @param $questionsummary the new summary to set.
1139 */
1140 public function set_question_summary($questionsummary) {
1141 $this->questionsummary = $questionsummary;
1142 $this->observer->notify_attempt_modified($this);
1143 }
1144
1145 /**
1146 * @return string a simple textual summary of the question that was asked.
1147 */
1148 public function get_question_summary() {
1149 return $this->questionsummary;
1150 }
1151
1152 /**
1153 * @return string a simple textual summary of response given.
1154 */
1155 public function get_response_summary() {
1156 return $this->responsesummary;
1157 }
1158
1159 /**
1160 * @return string a simple textual summary of the correct resonse.
1161 */
1162 public function get_right_answer_summary() {
1163 return $this->rightanswer;
1164 }
1165
fd7a8af5
TH
1166 /**
1167 * Whether this attempt at this question could be completed just by the
1168 * student interacting with the question, before {@link finish()} is called.
1169 *
1170 * @return boolean whether this attempt can finish naturally.
1171 */
1172 public function can_finish_during_attempt() {
1173 return $this->behaviour->can_finish_during_attempt();
1174 }
1175
dcd03928
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1176 /**
1177 * Perform the action described by $submitteddata.
1178 * @param array $submitteddata the submitted data the determines the action.
1179 * @param int $timestamp the time to record for the action. (If not given, use now.)
0a606a2b
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1180 * @param int $userid the user to attribute the action to. (If not given, use the current user.)
1181 * @param int $existingstepid used by the regrade code.
dcd03928 1182 */
94815ccf
TH
1183 public function process_action($submitteddata, $timestamp = null, $userid = null, $existingstepid = null) {
1184 $pendingstep = new question_attempt_pending_step($submitteddata, $timestamp, $userid, $existingstepid);
0a606a2b 1185 $this->discard_autosaved_step();
dcd03928
TH
1186 if ($this->behaviour->process_action($pendingstep) == self::KEEP) {
1187 $this->add_step($pendingstep);
1188 if ($pendingstep->response_summary_changed()) {
1189 $this->responsesummary = $pendingstep->get_new_response_summary();
1190 }
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TH
1191 if ($pendingstep->variant_number_changed()) {
1192 $this->variant = $pendingstep->get_new_variant_number();
1193 }
dcd03928
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1194 }
1195 }
1196
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1197 /**
1198 * Process an autosave.
1199 * @param array $submitteddata the submitted data the determines the action.
1200 * @param int $timestamp the time to record for the action. (If not given, use now.)
1201 * @param int $userid the user to attribute the action to. (If not given, use the current user.)
1202 * @return bool whether anything was saved.
1203 */
1204 public function process_autosave($submitteddata, $timestamp = null, $userid = null) {
1205 $pendingstep = new question_attempt_pending_step($submitteddata, $timestamp, $userid);
1206 if ($this->behaviour->process_autosave($pendingstep) == self::KEEP) {
1207 $this->add_autosaved_step($pendingstep);
1208 return true;
1209 }
1210 return false;
1211 }
1212
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1213 /**
1214 * Perform a finish action on this question attempt. This corresponds to an
1215 * external finish action, for example the user pressing Submit all and finish
1216 * in the quiz, rather than using one of the controls that is part of the
1217 * question.
1218 *
1219 * @param int $timestamp the time to record for the action. (If not given, use now.)
1220 * @param int $userid the user to attribute the aciton to. (If not given, use the current user.)
1221 */
1222 public function finish($timestamp = null, $userid = null) {
3d96b494 1223 $this->convert_autosaved_step_to_real_step();
dcd03928
TH
1224 $this->process_action(array('-finish' => 1), $timestamp, $userid);
1225 }
1226
1227 /**
1228 * Perform a regrade. This replays all the actions from $oldqa into this
1229 * attempt.
1230 * @param question_attempt $oldqa the attempt to regrade.
1231 * @param bool $finished whether the question attempt should be forced to be finished
1232 * after the regrade, or whether it may still be in progress (default false).
1233 */
1234 public function regrade(question_attempt $oldqa, $finished) {
1235 $first = true;
1236 foreach ($oldqa->get_step_iterator() as $step) {
94815ccf 1237 $this->observer->notify_step_deleted($step, $this);
9212fe7a 1238
dcd03928 1239 if ($first) {
9212fe7a 1240 // First step of the attempt.
dcd03928 1241 $first = false;
1da821bb 1242 $this->start($oldqa->behaviour, $oldqa->get_variant(), $step->get_all_data(),
94815ccf 1243 $step->get_timecreated(), $step->get_user_id(), $step->get_id());
9212fe7a
TH
1244
1245 } else if ($step->has_behaviour_var('finish') && count($step->get_submitted_data()) > 1) {
1246 // This case relates to MDL-32062. The upgrade code from 2.0
1247 // generates attempts where the final submit of the question
1248 // data, and the finish action, are in the same step. The system
1249 // cannot cope with that, so convert the single old step into
1250 // two new steps.
1251 $submitteddata = $step->get_submitted_data();
1252 unset($submitteddata['-finish']);
1253 $this->process_action($submitteddata,
1254 $step->get_timecreated(), $step->get_user_id(), $step->get_id());
1255 $this->finish($step->get_timecreated(), $step->get_user_id());
1256
dcd03928 1257 } else {
9212fe7a 1258 // This is the normal case. Replay the next step of the attempt.
dcd03928 1259 $this->process_action($step->get_submitted_data(),
94815ccf 1260 $step->get_timecreated(), $step->get_user_id(), $step->get_id());
dcd03928
TH
1261 }
1262 }
9212fe7a 1263
dcd03928
TH
1264 if ($finished) {
1265 $this->finish();
1266 }
1267 }
1268
1269 /**
1270 * Perform a manual grading action on this attempt.
53b8e256
TH
1271 * @param string $comment the comment being added.
1272 * @param float $mark the new mark. If null, then only a comment is added.
1273 * @param int $commentformat the FORMAT_... for $comment. Must be given.
dcd03928
TH
1274 * @param int $timestamp the time to record for the action. (If not given, use now.)
1275 * @param int $userid the user to attribute the aciton to. (If not given, use the current user.)
dcd03928 1276 */
53b8e256 1277 public function manual_grade($comment, $mark, $commentformat = null, $timestamp = null, $userid = null) {
dcd03928 1278 $submitteddata = array('-comment' => $comment);
53b8e256
TH
1279 if (is_null($commentformat)) {
1280 debugging('You should pass $commentformat to manual_grade.', DEBUG_DEVELOPER);
1281 $commentformat = FORMAT_HTML;
1282 }
1283 $submitteddata['-commentformat'] = $commentformat;
dcd03928
TH
1284 if (!is_null($mark)) {
1285 $submitteddata['-mark'] = $mark;
1286 $submitteddata['-maxmark'] = $this->maxmark;
1287 }
1288 $this->process_action($submitteddata, $timestamp, $userid);
1289 }
1290
1291 /** @return bool Whether this question attempt has had a manual comment added. */
1292 public function has_manual_comment() {
1293 foreach ($this->steps as $step) {
1294 if ($step->has_behaviour_var('comment')) {
1295 return true;
1296 }
1297 }
1298 return false;
1299 }
1300
1301 /**
1302 * @return array(string, int) the most recent manual comment that was added
1303 * to this question, and the FORMAT_... it is.
1304 */
1305 public function get_manual_comment() {
1306 foreach ($this->get_reverse_step_iterator() as $step) {
1307 if ($step->has_behaviour_var('comment')) {
1308 return array($step->get_behaviour_var('comment'),
1309 $step->get_behaviour_var('commentformat'));
1310 }
1311 }
1312 return array(null, null);
1313 }
1314
1eb470fc
TH
1315 /**
1316 * This is used by the manual grading code, particularly in association with
1317 * validation. If there is a comment submitted in the request, then use that,
1318 * otherwise use the latest comment for this question.
1319 * @return number the current mark for this question.
1320 * {@link get_fraction()} * {@link get_max_mark()}.
1321 */
1322 public function get_current_manual_comment() {
1323 $comment = $this->get_submitted_var($this->get_behaviour_field_name('comment'), PARAM_RAW);
1324 if (is_null($comment)) {
1325 return $this->get_manual_comment();
1326 } else {
1327 $commentformat = $this->get_submitted_var(
1328 $this->get_behaviour_field_name('commentformat'), PARAM_INT);
1329 if ($commentformat === null) {
1330 $commentformat = FORMAT_HTML;
1331 }
1332 return array($comment, $commentformat);
1333 }
1334 }
1335
dcd03928 1336 /**
038014c4 1337 * Break down a student response by sub part and classification. See also {@link question::classify_response}.
d50b05e6
JP
1338 * Used for response analysis.
1339 *
038014c4
JP
1340 * @param string $whichtries which tries to analyse for response analysis. Will be one of
1341 * question_attempt::FIRST_TRY, LAST_TRY or ALL_TRIES.
1342 * Defaults to question_attempt::LAST_TRY.
1343 * @return (question_classified_response|array)[] If $whichtries is question_attempt::FIRST_TRY or LAST_TRY index is subpartid
1344 * and values are question_classified_response instances.
1345 * If $whichtries is question_attempt::ALL_TRIES then first key is submitted response no
1346 * and the second key is subpartid.
dcd03928 1347 */
038014c4
JP
1348 public function classify_response($whichtries = self::LAST_TRY) {
1349 return $this->behaviour->classify_response($whichtries);
dcd03928
TH
1350 }
1351
1352 /**
1353 * Create a question_attempt_step from records loaded from the database.
1354 *
1355 * For internal use only.
1356 *
35d5f1c2 1357 * @param Iterator $records Raw records loaded from the database.
dcd03928 1358 * @param int $questionattemptid The id of the question_attempt to extract.
94815ccf 1359 * @return question_attempt The newly constructed question_attempt.
dcd03928 1360 */
35d5f1c2 1361 public static function load_from_records($records, $questionattemptid,
dcd03928 1362 question_usage_observer $observer, $preferredbehaviour) {
35d5f1c2 1363 $record = $records->current();
dcd03928 1364 while ($record->questionattemptid != $questionattemptid) {
35d5f1c2
TH
1365 $record = $records->next();
1366 if (!$records->valid()) {
f4fe3968 1367 throw new coding_exception("Question attempt {$questionattemptid} not found in the database.");
dcd03928 1368 }
35d5f1c2 1369 $record = $records->current();
dcd03928
TH
1370 }
1371
1372 try {
1373 $question = question_bank::load_question($record->questionid);
1374 } catch (Exception $e) {
1375 // The question must have been deleted somehow. Create a missing
1376 // question to use in its place.
1377 $question = question_bank::get_qtype('missingtype')->make_deleted_instance(
1378 $record->questionid, $record->maxmark + 0);
1379 }
1380
1381 $qa = new question_attempt($question, $record->questionusageid,
1382 null, $record->maxmark + 0);
1383 $qa->set_database_id($record->questionattemptid);
94815ccf 1384 $qa->set_slot($record->slot);
1da821bb 1385 $qa->variant = $record->variant + 0;
dcd03928 1386 $qa->minfraction = $record->minfraction + 0;
4e3d8293 1387 $qa->maxfraction = $record->maxfraction + 0;
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TH
1388 $qa->set_flagged($record->flagged);
1389 $qa->questionsummary = $record->questionsummary;
1390 $qa->rightanswer = $record->rightanswer;
1391 $qa->responsesummary = $record->responsesummary;
1392 $qa->timemodified = $record->timemodified;
1393
1394 $qa->behaviour = question_engine::make_behaviour(
1395 $record->behaviour, $qa, $preferredbehaviour);
0a606a2b 1396 $qa->observer = $observer;
dcd03928 1397
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TH
1398 // If attemptstepid is null (which should not happen, but has happened
1399 // due to corrupt data, see MDL-34251) then the current pointer in $records
1400 // will not be advanced in the while loop below, and we get stuck in an
1401 // infinite loop, since this method is supposed to always consume at
1402 // least one record. Therefore, in this case, advance the record here.
1403 if (is_null($record->attemptstepid)) {
1404 $records->next();
1405 }
1406
dcd03928 1407 $i = 0;
0a606a2b
TH
1408 $autosavedstep = null;
1409 $autosavedsequencenumber = null;
dcd03928 1410 while ($record && $record->questionattemptid == $questionattemptid && !is_null($record->attemptstepid)) {
0a606a2b 1411 $sequencenumber = $record->sequencenumber;
dc1ee5cb 1412 $nextstep = question_attempt_step::load_from_records($records, $record->attemptstepid, $qa->get_question()->get_type_name());
0a606a2b
TH
1413
1414 if ($sequencenumber < 0) {
1415 if (!$autosavedstep) {
1416 $autosavedstep = $nextstep;
1417 $autosavedsequencenumber = -$sequencenumber;
1418 } else {
1419 // Old redundant data. Mark it for deletion.
1420 $qa->observer->notify_step_deleted($nextstep, $qa);
1421 }
1422 } else {
1423 $qa->steps[$i] = $nextstep;
1424 if ($i == 0) {
1425 $question->apply_attempt_state($qa->steps[0]);
1426 }
1427 $i++;
dcd03928 1428 }
0a606a2b 1429
35d5f1c2
TH
1430 if ($records->valid()) {
1431 $record = $records->current();
1432 } else {
1433 $record = false;
1434 }
dcd03928
TH
1435 }
1436
0a606a2b
TH
1437 if ($autosavedstep) {
1438 if ($autosavedsequencenumber >= $i) {
1439 $qa->autosavedstep = $autosavedstep;
1440 $qa->steps[$i] = $qa->autosavedstep;
1441 } else {
1442 $qa->observer->notify_step_deleted($autosavedstep, $qa);
1443 }
1444 }
dcd03928
TH
1445
1446 return $qa;
1447 }
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JP
1448
1449 /**
1450 * Allow access to steps with responses submitted by students for grading in a question attempt.
1451 *
1452 * @return question_attempt_steps_with_submitted_response_iterator to access all steps with submitted data for questions that
1453 * allow multiple submissions that count towards grade, per attempt.
1454 */
1455 public function get_steps_with_submitted_response_iterator() {
1456 return new question_attempt_steps_with_submitted_response_iterator($this);
1457 }
dcd03928
TH
1458}
1459
1460
1461/**
1462 * This subclass of question_attempt pretends that only part of the step history
1463 * exists. It is used for rendering the question in past states.
1464 *
1465 * All methods that try to modify the question_attempt throw exceptions.
1466 *
1467 * @copyright 2010 The Open University
1468 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1469 */
1470class question_attempt_with_restricted_history extends question_attempt {
1471 /**
1472 * @var question_attempt the underlying question_attempt.
1473 */
1474 protected $baseqa;
1475
1476 /**
1477 * Create a question_attempt_with_restricted_history
1478 * @param question_attempt $baseqa The question_attempt to make a restricted version of.
1479 * @param int $lastseq the index of the last step to include.
1480 * @param string $preferredbehaviour the preferred behaviour. It is slightly
1481 * annoyting that this needs to be passed, but unavoidable for now.
1482 */
1483 public function __construct(question_attempt $baseqa, $lastseq, $preferredbehaviour) {
f123d67f
TH
1484 $this->baseqa = $baseqa->get_full_qa();
1485
1486 if ($lastseq < 0 || $lastseq >= $this->baseqa->get_num_steps()) {
1487 throw new coding_exception('$lastseq out of range', $lastseq);
dcd03928
TH
1488 }
1489
f123d67f 1490 $this->steps = array_slice($this->baseqa->steps, 0, $lastseq + 1);
dcd03928
TH
1491 $this->observer = new question_usage_null_observer();
1492
1493 // This should be a straight copy of all the remaining fields.
f123d67f
TH
1494 $this->id = $this->baseqa->id;
1495 $this->usageid = $this->baseqa->usageid;
1496 $this->slot = $this->baseqa->slot;
1497 $this->question = $this->baseqa->question;
1498 $this->maxmark = $this->baseqa->maxmark;
1499 $this->minfraction = $this->baseqa->minfraction;
4e3d8293 1500 $this->maxfraction = $this->baseqa->maxfraction;
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1501 $this->questionsummary = $this->baseqa->questionsummary;
1502 $this->responsesummary = $this->baseqa->responsesummary;
1503 $this->rightanswer = $this->baseqa->rightanswer;
1504 $this->flagged = $this->baseqa->flagged;
dcd03928
TH
1505
1506 // Except behaviour, where we need to create a new one.
1507 $this->behaviour = question_engine::make_behaviour(
f123d67f
TH
1508 $this->baseqa->get_behaviour_name(), $this, $preferredbehaviour);
1509 }
1510
1511 public function get_full_qa() {
1512 return $this->baseqa;
dcd03928
TH
1513 }
1514
1515 public function get_full_step_iterator() {
1516 return $this->baseqa->get_step_iterator();
1517 }
1518
1519 protected function add_step(question_attempt_step $step) {
1520 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1521 }
072db71c 1522 public function process_action($submitteddata, $timestamp = null, $userid = null, $existingstepid = null) {
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TH
1523 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1524 }
072db71c 1525 public function start($preferredbehaviour, $variant, $submitteddata = array(), $timestamp = null, $userid = null, $existingstepid = null) {
dcd03928
TH
1526 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1527 }
1528
1529 public function set_database_id($id) {
1530 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1531 }
1532 public function set_flagged($flagged) {
1533 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1534 }
94815ccf 1535 public function set_slot($slot) {
dcd03928
TH
1536 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1537 }
1538 public function set_question_summary($questionsummary) {
1539 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1540 }
1541 public function set_usage_id($usageid) {
1542 coding_exception('Cannot modify a question_attempt_with_restricted_history.');
1543 }
1544}
1545
1546
1547/**
1548 * A class abstracting access to the {@link question_attempt::$states} array.
1549 *
1550 * This is actively linked to question_attempt. If you add an new step
1551 * mid-iteration, then it will be included.
1552 *
1553 * @copyright 2009 The Open University
1554 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1555 */
1556class question_attempt_step_iterator implements Iterator, ArrayAccess {
1557 /** @var question_attempt the question_attempt being iterated over. */
1558 protected $qa;
1559 /** @var integer records the current position in the iteration. */
1560 protected $i;
1561
1562 /**
1563 * Do not call this constructor directly.
1564 * Use {@link question_attempt::get_step_iterator()}.
1565 * @param question_attempt $qa the attempt to iterate over.
1566 */
1567 public function __construct(question_attempt $qa) {
1568 $this->qa = $qa;
1569 $this->rewind();
1570 }
1571
1572 /** @return question_attempt_step */
1573 public function current() {
1574 return $this->offsetGet($this->i);
1575 }
1576 /** @return int */
1577 public function key() {
1578 return $this->i;
1579 }
1580 public function next() {
1581 ++$this->i;
1582 }
1583 public function rewind() {
1584 $this->i = 0;
1585 }
1586 /** @return bool */
1587 public function valid() {
1588 return $this->offsetExists($this->i);
1589 }
1590
1591 /** @return bool */
1592 public function offsetExists($i) {
1593 return $i >= 0 && $i < $this->qa->get_num_steps();
1594 }
1595 /** @return question_attempt_step */
1596 public function offsetGet($i) {
1597 return $this->qa->get_step($i);
1598 }
1599 public function offsetSet($offset, $value) {
1600 throw new coding_exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot set.');
1601 }
1602 public function offsetUnset($offset) {
1603 throw new coding_exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot unset.');
1604 }
1605}
1606
1607
1608/**
1609 * A variant of {@link question_attempt_step_iterator} that iterates through the
1610 * steps in reverse order.
1611 *
1612 * @copyright 2009 The Open University
1613 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1614 */
1615class question_attempt_reverse_step_iterator extends question_attempt_step_iterator {
1616 public function next() {
1617 --$this->i;
1618 }
1619
1620 public function rewind() {
1621 $this->i = $this->qa->get_num_steps() - 1;
1622 }
1623}
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JP
1624
1625/**
1626 * A variant of {@link question_attempt_step_iterator} that iterates through the
1627 * steps with submitted tries.
1628 *
1629 * @copyright 2014 The Open University
1630 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1631 */
1632class question_attempt_steps_with_submitted_response_iterator extends question_attempt_step_iterator implements Countable {
1633
1634 /** @var question_attempt the question_attempt being iterated over. */
1635 protected $qa;
1636
1637 /** @var integer records the current position in the iteration. */
1638 protected $submittedresponseno;
1639
1640 /**
1641 * Index is the submitted response number and value is the step no.
1642 *
1643 * @var int[]
1644 */
1645 protected $stepswithsubmittedresponses;
1646
1647 /**
1648 * Do not call this constructor directly.
1649 * Use {@link question_attempt::get_submission_step_iterator()}.
1650 * @param question_attempt $qa the attempt to iterate over.
1651 */
1652 public function __construct(question_attempt $qa) {
1653 $this->qa = $qa;
1654 $this->find_steps_with_submitted_response();
1655 $this->rewind();
1656 }
1657
1658 /**
1659 * Find the step nos in which a student has submitted a response. Including any step with a response that is saved before
1660 * the question attempt finishes.
1661 *
1662 * Called from constructor, should not be called from elsewhere.
1663 *
1664 */
1665 protected function find_steps_with_submitted_response() {
1666 $stepnos = array();
1667 $lastsavedstep = null;
1668 foreach ($this->qa->get_step_iterator() as $stepno => $step) {
1669 if ($this->qa->get_behaviour()->step_has_a_submitted_response($step)) {
1670 $stepnos[] = $stepno;
1671 $lastsavedstep = null;
1672 } else {
1673 $qtdata = $step->get_qt_data();
1674 if (count($qtdata)) {
1675 $lastsavedstep = $stepno;
1676 }
1677 }
1678 }
1679
1680 if (!is_null($lastsavedstep)) {
1681 $stepnos[] = $lastsavedstep;
1682 }
1683 if (empty($stepnos)) {
1684 $this->stepswithsubmittedresponses = array();
1685 } else {
1686 // Re-index array so index starts with 1.
1687 $this->stepswithsubmittedresponses = array_combine(range(1, count($stepnos)), $stepnos);
1688 }
1689 }
1690
1691 /** @return question_attempt_step */
1692 public function current() {
1693 return $this->offsetGet($this->submittedresponseno);
1694 }
1695 /** @return int */
1696 public function key() {
1697 return $this->submittedresponseno;
1698 }
1699 public function next() {
1700 ++$this->submittedresponseno;
1701 }
1702 public function rewind() {
1703 $this->submittedresponseno = 1;
1704 }
1705 /** @return bool */
1706 public function valid() {
038014c4 1707 return $this->submittedresponseno >= 1 && $this->submittedresponseno <= count($this->stepswithsubmittedresponses);
99caa248
JP
1708 }
1709
1710 /**
1711 * @param int $submittedresponseno
1712 * @return bool
1713 */
1714 public function offsetExists($submittedresponseno) {
1715 return $submittedresponseno >= 1;
1716 }
1717
1718 /**
1719 * @param int $submittedresponseno
1720 * @return question_attempt_step
1721 */
1722 public function offsetGet($submittedresponseno) {
1723 if ($submittedresponseno > count($this->stepswithsubmittedresponses)) {
1724 return null;
1725 } else {
1726 return $this->qa->get_step($this->step_no_for_try($submittedresponseno));
1727 }
1728 }
1729
1730 /**
1731 * @return int the count of steps with tries.
1732 */
1733 public function count() {
1734 return count($this->stepswithsubmittedresponses);
1735 }
1736
1737 /**
1738 * @param int $submittedresponseno
1739 * @throws coding_exception
1740 * @return int|null the step number or null if there is no such submitted response.
1741 */
1742 public function step_no_for_try($submittedresponseno) {
1743 if (isset($this->stepswithsubmittedresponses[$submittedresponseno])) {
1744 return $this->stepswithsubmittedresponses[$submittedresponseno];
1745 } else if ($submittedresponseno > count($this->stepswithsubmittedresponses)) {
1746 return null;
1747 } else {
1748 throw new coding_exception('Try number not found. It should be 1 or more.');
1749 }
1750 }
1751
1752 public function offsetSet($offset, $value) {
1753 throw new coding_exception('You are only allowed read-only access to question_attempt::states '.
1754 'through a question_attempt_step_iterator. Cannot set.');
1755 }
1756 public function offsetUnset($offset) {
1757 throw new coding_exception('You are only allowed read-only access to question_attempt::states '.
1758 'through a question_attempt_step_iterator. Cannot unset.');
1759 }
1760
1761}