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- Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
- Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
- PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
/question/behaviour/ -> behaviourbase.php (source)
1 <?php 2 // This file is part of Moodle - http://moodle.org/ 3 // 4 // Moodle is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // Moodle is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU General Public License for more details. 13 // 14 // You should have received a copy of the GNU General Public License 15 // along with Moodle. If not, see <http://www.gnu.org/licenses/>. 16 17 /** 18 * Defines the question behaviour base class 19 * 20 * @package moodlecore 21 * @subpackage questionbehaviours 22 * @copyright 2009 The Open University 23 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 24 */ 25 26 27 defined('MOODLE_INTERNAL') || die(); 28 29 30 /** 31 * The base class for question behaviours. 32 * 33 * A question behaviour is used by the question engine, specifically by 34 * a {@link question_attempt} to manage the flow of actions a student can take 35 * as they work through a question, and later, as a teacher manually grades it. 36 * In turn, the behaviour will delegate certain processing to the 37 * relevant {@link question_definition}. 38 * 39 * @copyright 2009 The Open University 40 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 41 */ 42 abstract class question_behaviour { 43 44 /** @var question_attempt the question attempt we are managing. */ 45 protected $qa; 46 47 /** @var question_definition shortcut to $qa->get_question(). */ 48 protected $question; 49 50 /** 51 * Normally you should not call this constuctor directly. The appropriate 52 * behaviour object is created automatically as part of 53 * {@link question_attempt::start()}. 54 * @param question_attempt $qa the question attempt we will be managing. 55 * @param string $preferredbehaviour the type of behaviour that was actually 56 * requested. This information is not needed in most cases, the type of 57 * subclass is enough, but occasionally it is needed. 58 */ 59 public function __construct(question_attempt $qa, $preferredbehaviour) { 60 $this->qa = $qa; 61 $this->question = $qa->get_question(false); 62 if (!$this->is_compatible_question($this->question)) { 63 throw new coding_exception('This behaviour (' . $this->get_name() . 64 ') cannot work with this question (' . get_class($this->question) . ')'); 65 } 66 } 67 68 /** 69 * Some behaviours can only work with certing types of question. This method 70 * allows the behaviour to verify that a question is compatible. 71 * 72 * This implementation is only provided for backwards-compatibility. You should 73 * override this method if you are implementing a behaviour. 74 * 75 * @param question_definition $question the question. 76 */ 77 public abstract function is_compatible_question(question_definition $question); 78 79 /** 80 * @return string the name of this behaviour. For example the name of 81 * qbehaviour_mymodle is 'mymodel'. 82 */ 83 public function get_name() { 84 return substr(get_class($this), 11); 85 } 86 87 /** 88 * Whether the current attempt at this question could be completed just by the 89 * student interacting with the question, before $qa->finish() is called. 90 * 91 * @return boolean whether the attempt can finish naturally. 92 */ 93 public function can_finish_during_attempt() { 94 return false; 95 } 96 97 /** 98 * Cause the question to be renderered. This gets the appropriate behaviour 99 * renderer using {@link get_renderer()}, and adjusts the display 100 * options using {@link adjust_display_options()} and then calls 101 * {@link core_question_renderer::question()} to do the work. 102 * @param question_display_options $options controls what should and should not be displayed. 103 * @param string|null $number the question number to display. 104 * @param core_question_renderer $qoutput the question renderer that will coordinate everything. 105 * @param qtype_renderer $qtoutput the question type renderer that will be helping. 106 * @return string HTML fragment. 107 */ 108 public function render(question_display_options $options, $number, 109 core_question_renderer $qoutput, qtype_renderer $qtoutput) { 110 $behaviouroutput = $this->get_renderer($qoutput->get_page()); 111 $options = clone($options); 112 $this->adjust_display_options($options); 113 return $qoutput->question($this->qa, $behaviouroutput, $qtoutput, $options, $number); 114 } 115 116 /** 117 * Checks whether the users is allow to be served a particular file. 118 * @param question_display_options $options the options that control display of the question. 119 * @param string $component the name of the component we are serving files for. 120 * @param string $filearea the name of the file area. 121 * @param array $args the remaining bits of the file path. 122 * @param bool $forcedownload whether the user must be forced to download the file. 123 * @return bool true if the user can access this file. 124 */ 125 public function check_file_access($options, $component, $filearea, $args, $forcedownload) { 126 $this->adjust_display_options($options); 127 128 if ($component == 'question' && $filearea == 'response_bf_comment') { 129 foreach ($this->qa->get_step_iterator() as $attemptstep) { 130 if ($attemptstep->get_id() == $args[0]) { 131 return true; 132 } 133 } 134 135 return false; 136 } 137 138 return $this->question->check_file_access($this->qa, $options, $component, 139 $filearea, $args, $forcedownload); 140 } 141 142 /** 143 * @param moodle_page $page the page to render for. 144 * @return qbehaviour_renderer get the appropriate renderer to use for this model. 145 */ 146 public function get_renderer(moodle_page $page) { 147 return $page->get_renderer(get_class($this)); 148 } 149 150 /** 151 * Make any changes to the display options before a question is rendered, so 152 * that it can be displayed in a way that is appropriate for the statue it is 153 * currently in. For example, by default, if the question is finished, we 154 * ensure that it is only ever displayed read-only. 155 * @param question_display_options $options the options to adjust. Just change 156 * the properties of this object - objects are passed by referece. 157 */ 158 public function adjust_display_options(question_display_options $options) { 159 if (!$this->qa->has_marks()) { 160 $options->correctness = false; 161 $options->numpartscorrect = false; 162 } 163 if ($this->qa->get_state()->is_finished()) { 164 $options->readonly = true; 165 $options->numpartscorrect = $options->numpartscorrect && 166 $this->qa->get_state()->is_partially_correct() && 167 !empty($this->question->shownumcorrect); 168 } else { 169 $options->hide_all_feedback(); 170 } 171 } 172 173 /** 174 * Get the most applicable hint for the question in its current state. 175 * @return question_hint the most applicable hint, or null, if none. 176 */ 177 public function get_applicable_hint() { 178 return null; 179 } 180 181 /** 182 * What is the minimum fraction that can be scored for this question. 183 * Normally this will be based on $this->question->get_min_fraction(), 184 * but may be modified in some way by the behaviour. 185 * 186 * @return number the minimum fraction when this question is attempted under 187 * this behaviour. 188 */ 189 public function get_min_fraction() { 190 return 0; 191 } 192 193 /** 194 * Return the maximum possible fraction that can be scored for this question. 195 * Normally this will be based on $this->question->get_max_fraction(), 196 * but may be modified in some way by the behaviour. 197 * 198 * @return number the maximum fraction when this question is attempted under 199 * this behaviour. 200 */ 201 public function get_max_fraction() { 202 return $this->question->get_max_fraction(); 203 } 204 205 /** 206 * Return an array of the behaviour variables that could be submitted 207 * as part of a question of this type, with their types, so they can be 208 * properly cleaned. 209 * @return array variable name => PARAM_... constant. 210 */ 211 public function get_expected_data() { 212 if (!$this->qa->get_state()->is_finished()) { 213 return array(); 214 } 215 216 $vars = array('comment' => question_attempt::PARAM_RAW_FILES, 'commentformat' => PARAM_INT); 217 if ($this->qa->get_max_mark()) { 218 $vars['mark'] = PARAM_RAW_TRIMMED; 219 $vars['maxmark'] = PARAM_FLOAT; 220 } 221 return $vars; 222 } 223 224 /** 225 * Return an array of question type variables for the question in its current 226 * state. Normally, if {@link adjust_display_options()} would set 227 * {@link question_display_options::$readonly} to true, then this method 228 * should return an empty array, otherwise it should return 229 * $this->question->get_expected_data(). Thus, there should be little need to 230 * override this method. 231 * @return array|string variable name => PARAM_... constant, or, as a special case 232 * that should only be used in unavoidable, the constant question_attempt::USE_RAW_DATA 233 * meaning take all the raw submitted data belonging to this question. 234 */ 235 public function get_expected_qt_data() { 236 $fakeoptions = new question_display_options(); 237 $fakeoptions->readonly = false; 238 $this->adjust_display_options($fakeoptions); 239 if ($fakeoptions->readonly) { 240 return array(); 241 } else { 242 return $this->question->get_expected_data(); 243 } 244 } 245 246 /** 247 * Return an array of any im variables, and the value required to get full 248 * marks. 249 * @return array variable name => value. 250 */ 251 public function get_correct_response() { 252 return array(); 253 } 254 255 /** 256 * Generate a brief, plain-text, summary of this question. This is used by 257 * various reports. This should show the particular variant of the question 258 * as presented to students. For example, the calculated quetsion type would 259 * fill in the particular numbers that were presented to the student. 260 * This method will return null if such a summary is not possible, or 261 * inappropriate. 262 * 263 * Normally, this method delegates to {question_definition::get_question_summary()}. 264 * 265 * @return string|null a plain text summary of this question. 266 */ 267 public function get_question_summary() { 268 return $this->question->get_question_summary(); 269 } 270 271 /** 272 * Generate a brief, plain-text, summary of the correct answer to this question. 273 * This is used by various reports, and can also be useful when testing. 274 * This method will return null if such a summary is not possible, or 275 * inappropriate. 276 * 277 * @return string|null a plain text summary of the right answer to this question. 278 */ 279 public function get_right_answer_summary() { 280 return null; 281 } 282 283 /** 284 * Used by {@link start_based_on()} to get the data needed to start a new 285 * attempt from the point this attempt has go to. 286 * @return array name => value pairs. 287 */ 288 public function get_resume_data() { 289 $olddata = $this->qa->get_step(0)->get_all_data(); 290 $olddata = $this->qa->get_last_qt_data() + $olddata; 291 $olddata = $this->get_our_resume_data() + $olddata; 292 return $olddata; 293 } 294 295 /** 296 * Used by {@link start_based_on()} to get the data needed to start a new 297 * attempt from the point this attempt has go to. 298 * @return unknown_type 299 */ 300 protected function get_our_resume_data() { 301 return array(); 302 } 303 304 /** 305 * Classify responses for this question into a number of sub parts and response classes as defined by 306 * {@link \question_type::get_possible_responses} for this question type. 307 * 308 * @param string $whichtries which tries to analyse for response analysis. Will be one of 309 * question_attempt::FIRST_TRY, LAST_TRY or ALL_TRIES. 310 * Defaults to question_attempt::LAST_TRY. 311 * @return (question_classified_response|array)[] If $whichtries is question_attempt::FIRST_TRY or LAST_TRY index is subpartid 312 * and values are question_classified_response instances. 313 * If $whichtries is question_attempt::ALL_TRIES then first key is submitted response no 314 * and the second key is subpartid. 315 */ 316 public function classify_response($whichtries = question_attempt::LAST_TRY) { 317 if ($whichtries == question_attempt::LAST_TRY) { 318 return $this->question->classify_response($this->qa->get_last_qt_data()); 319 } else { 320 $stepswithsubmit = $this->qa->get_steps_with_submitted_response_iterator(); 321 if ($whichtries == question_attempt::FIRST_TRY) { 322 $firsttry = $stepswithsubmit[1]; 323 if ($firsttry) { 324 return $this->question->classify_response($firsttry->get_qt_data()); 325 } else { 326 return $this->question->classify_response(array()); 327 } 328 } else { 329 $classifiedresponses = array(); 330 foreach ($stepswithsubmit as $submittedresponseno => $step) { 331 $classifiedresponses[$submittedresponseno] = $this->question->classify_response($step->get_qt_data()); 332 } 333 return $classifiedresponses; 334 } 335 } 336 } 337 338 /** 339 * Generate a brief textual description of the current state of the question, 340 * normally displayed under the question number. 341 * 342 * @param bool $showcorrectness Whether right/partial/wrong states should 343 * be distinguised. 344 * @return string a brief summary of the current state of the qestion attempt. 345 */ 346 public function get_state_string($showcorrectness) { 347 return $this->qa->get_state()->default_string($showcorrectness); 348 } 349 350 public abstract function summarise_action(question_attempt_step $step); 351 352 /** 353 * Initialise the first step in a question attempt when a new 354 * {@link question_attempt} is being started. 355 * 356 * This method must call $this->question->start_attempt($step, $variant), and may 357 * perform additional processing if the behaviour requries it. 358 * 359 * @param question_attempt_step $step the first step of the 360 * question_attempt being started. 361 * @param int $variant which variant of the question to use. 362 */ 363 public function init_first_step(question_attempt_step $step, $variant) { 364 $this->question->start_attempt($step, $variant); 365 $step->set_state(question_state::$todo); 366 } 367 368 /** 369 * When an attempt is started based on a previous attempt (see 370 * {@link question_attempt::start_based_on}) this method is called to setup 371 * the new attempt. 372 * 373 * This method must call $this->question->apply_attempt_state($step), and may 374 * perform additional processing if the behaviour requries it. 375 * 376 * @param question_attempt_step The first step of the {@link question_attempt} 377 * being loaded. 378 */ 379 public function apply_attempt_state(question_attempt_step $step) { 380 $this->question->apply_attempt_state($step); 381 $step->set_state(question_state::$todo); 382 } 383 384 /** 385 * Checks whether two manual grading actions are the same. That is, whether 386 * the comment, and the mark (if given) is the same. 387 * 388 * @param question_attempt_step $pendingstep contains the new responses. 389 * @return bool whether the new response is the same as we already have. 390 */ 391 protected function is_same_comment($pendingstep) { 392 $previouscomment = $this->qa->get_last_behaviour_var('comment'); 393 $newcomment = $pendingstep->get_behaviour_var('comment'); 394 395 // When the teacher leaves the comment empty, $previouscomment is an empty string but $newcomment is null, 396 // therefore they are not equal to each other. That's why checking if $previouscomment != $newcomment is not enough. 397 if (($previouscomment != $newcomment) && !(is_null($previouscomment) && html_is_blank($newcomment))) { 398 // The comment has changed. 399 return false; 400 } 401 402 if (!html_is_blank($newcomment)) { 403 // Check comment format. 404 $previouscommentformat = $this->qa->get_last_behaviour_var('commentformat'); 405 $newcommentformat = $pendingstep->get_behaviour_var('commentformat'); 406 if ($previouscommentformat != $newcommentformat) { 407 return false; 408 } 409 } 410 411 // So, now we know the comment is the same, so check the mark, if present. 412 $previousfraction = $this->qa->get_fraction(); 413 $newmark = question_utils::clean_param_mark($pendingstep->get_behaviour_var('mark')); 414 415 if (is_null($previousfraction)) { 416 return is_null($newmark) || $newmark === ''; 417 } else if (is_null($newmark) || $newmark === '') { 418 return false; 419 } 420 421 $newfraction = $newmark / $pendingstep->get_behaviour_var('maxmark'); 422 423 return abs($newfraction - $previousfraction) < 0.0000001; 424 } 425 426 /** 427 * The main entry point for processing an action. 428 * 429 * All the various operations that can be performed on a 430 * {@link question_attempt} get channeled through this function, except for 431 * {@link question_attempt::start()} which goes to {@link init_first_step()}. 432 * {@link question_attempt::finish()} becomes an action with im vars 433 * finish => 1, and manual comment/grade becomes an action with im vars 434 * comment => comment text, and mark => ..., max_mark => ... if the question 435 * is graded. 436 * 437 * This method should first determine whether the action is significant. For 438 * example, if no actual action is being performed, but instead the current 439 * responses are being saved, and there has been no change since the last 440 * set of responses that were saved, this the action is not significatn. In 441 * this case, this method should return {@link question_attempt::DISCARD}. 442 * Otherwise it should return {@link question_attempt::KEEP}. 443 * 444 * If the action is significant, this method should also perform any 445 * necessary updates to $pendingstep. For example, it should call 446 * {@link question_attempt_step::set_state()} to set the state that results 447 * from this action, and if this is a grading action, it should call 448 * {@link question_attempt_step::set_fraction()}. 449 * 450 * This method can also call {@link question_attempt_step::set_behaviour_var()} to 451 * store additional infomation. There are two main uses for this. This can 452 * be used to store the result of any randomisation done. It is important to 453 * store the result of randomisation once, and then in future use the same 454 * outcome if the actions are ever replayed. This is how regrading works. 455 * The other use is to cache the result of expensive computations performed 456 * on the raw response data, so that subsequent display and review of the 457 * question does not have to repeat the same expensive computations. 458 * 459 * Often this method is implemented as a dispatching method that examines 460 * the pending step to determine the kind of action being performed, and 461 * then calls a more specific method like {@link process_save()} or 462 * {@link process_comment()}. Look at some of the standard behaviours 463 * for examples. 464 * 465 * @param question_attempt_pending_step $pendingstep a partially initialised step 466 * containing all the information about the action that is being peformed. This 467 * information can be accessed using {@link question_attempt_step::get_behaviour_var()}. 468 * @return bool either {@link question_attempt::KEEP} or {@link question_attempt::DISCARD} 469 */ 470 public abstract function process_action(question_attempt_pending_step $pendingstep); 471 472 /** 473 * Auto-saved data. By default this does nothing. interesting processing is 474 * done in {@link question_behaviour_with_save}. 475 * 476 * @param question_attempt_pending_step $pendingstep a partially initialised step 477 * containing all the information about the action that is being peformed. This 478 * information can be accessed using {@link question_attempt_step::get_behaviour_var()}. 479 * @return bool either {@link question_attempt::KEEP} or {@link question_attempt::DISCARD} 480 */ 481 public function process_autosave(question_attempt_pending_step $pendingstep) { 482 return question_attempt::DISCARD; 483 } 484 485 /** 486 * Implementation of processing a manual comment/grade action that should 487 * be suitable for most subclasses. 488 * @param question_attempt_pending_step $pendingstep a partially initialised step 489 * containing all the information about the action that is being peformed. 490 * @return bool either {@link question_attempt::KEEP} 491 */ 492 public function process_comment(question_attempt_pending_step $pendingstep) { 493 if (!$this->qa->get_state()->is_finished()) { 494 throw new coding_exception('Cannot manually grade a question before it is finshed.'); 495 } 496 497 if ($this->is_same_comment($pendingstep)) { 498 return question_attempt::DISCARD; 499 } 500 501 if ($pendingstep->has_behaviour_var('mark')) { 502 $mark = question_utils::clean_param_mark($pendingstep->get_behaviour_var('mark')); 503 if ($mark === null) { 504 throw new coding_exception('Inalid number format ' . $pendingstep->get_behaviour_var('mark') . 505 ' when processing a manual grading action.', 'Question ' . $this->question->id . 506 ', slot ' . $this->qa->get_slot()); 507 508 } else if ($mark === '') { 509 $fraction = null; 510 511 } else { 512 $fraction = $mark / $pendingstep->get_behaviour_var('maxmark'); 513 if ($fraction > $this->qa->get_max_fraction() || $fraction < $this->qa->get_min_fraction()) { 514 throw new coding_exception('Score out of range when processing ' . 515 'a manual grading action.', 'Question ' . $this->question->id . 516 ', slot ' . $this->qa->get_slot() . ', fraction ' . $fraction); 517 } 518 } 519 520 $pendingstep->set_fraction($fraction); 521 } 522 523 $pendingstep->set_state($this->qa->get_state()->corresponding_commented_state( 524 $pendingstep->get_fraction())); 525 return question_attempt::KEEP; 526 } 527 528 /** 529 * @param $comment the comment text to format. If omitted, 530 * $this->qa->get_manual_comment() is used. 531 * @param $commentformat the format of the comment, one of the FORMAT_... constants. 532 * @param $context the quiz context. 533 * @return string the comment, ready to be output. 534 */ 535 public function format_comment($comment = null, $commentformat = null, $context = null) { 536 $formatoptions = new stdClass(); 537 $formatoptions->noclean = true; 538 $formatoptions->para = false; 539 540 if (is_null($comment)) { 541 list($comment, $commentformat, $commentstep) = $this->qa->get_manual_comment(); 542 } 543 544 if ($context !== null) { 545 $comment = $this->qa->rewrite_response_pluginfile_urls($comment, $context->id, 'bf_comment', $commentstep); 546 } 547 548 return format_text($comment, $commentformat, $formatoptions); 549 } 550 551 /** 552 * @return string a summary of a manual comment action. 553 * @param question_attempt_step $step 554 */ 555 protected function summarise_manual_comment($step) { 556 $a = new stdClass(); 557 if ($step->has_behaviour_var('comment')) { 558 $comment = question_utils::to_plain_text($step->get_behaviour_var('comment'), 559 $step->get_behaviour_var('commentformat')); 560 $a->comment = shorten_text($comment, 200); 561 } else { 562 $a->comment = ''; 563 } 564 565 $mark = question_utils::clean_param_mark($step->get_behaviour_var('mark')); 566 if (is_null($mark) || $mark === '') { 567 return get_string('commented', 'question', $a->comment); 568 } else { 569 $a->mark = $mark / $step->get_behaviour_var('maxmark') * $this->qa->get_max_mark(); 570 return get_string('manuallygraded', 'question', $a); 571 } 572 } 573 574 public function summarise_start($step) { 575 return get_string('started', 'question'); 576 } 577 578 public function summarise_finish($step) { 579 return get_string('attemptfinished', 'question'); 580 } 581 582 /** 583 * Does this step include a response submitted by a student? 584 * 585 * This method should return true for any attempt explicitly submitted by a student. The question engine itself will also 586 * automatically recognise any last saved response before the attempt is finished, you don't need to return true here for these 587 * steps with responses which are not explicitly submitted by the student. 588 * 589 * @param question_attempt_step $step 590 * @return bool is this a step within a question attempt that includes a submitted response by a student. 591 */ 592 public function step_has_a_submitted_response($step) { 593 return false; 594 } 595 } 596 597 598 /** 599 * A subclass of {@link question_behaviour} that implements a save 600 * action that is suitable for most questions that implement the 601 * {@link question_manually_gradable} interface. 602 * 603 * @copyright 2009 The Open University 604 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 605 */ 606 abstract class question_behaviour_with_save extends question_behaviour { 607 public function required_question_definition_type() { 608 return 'question_manually_gradable'; 609 } 610 611 public function apply_attempt_state(question_attempt_step $step) { 612 parent::apply_attempt_state($step); 613 if ($this->question->is_complete_response($step->get_qt_data())) { 614 $step->set_state(question_state::$complete); 615 } 616 } 617 618 /** 619 * Work out whether the response in $pendingstep are significantly different 620 * from the last set of responses we have stored. 621 * @param question_attempt_step $pendingstep contains the new responses. 622 * @return bool whether the new response is the same as we already have. 623 */ 624 protected function is_same_response(question_attempt_step $pendingstep) { 625 return $this->question->is_same_response( 626 $this->qa->get_last_step()->get_qt_data(), $pendingstep->get_qt_data()); 627 } 628 629 /** 630 * Work out whether the response in $pendingstep represent a complete answer 631 * to the question. Normally this will call 632 * {@link question_manually_gradable::is_complete_response}, but some 633 * behaviours, for example the CBM ones, have their own parts to the 634 * response. 635 * @param question_attempt_step $pendingstep contains the new responses. 636 * @return bool whether the new response is complete. 637 */ 638 protected function is_complete_response(question_attempt_step $pendingstep) { 639 return $this->question->is_complete_response($pendingstep->get_qt_data()); 640 } 641 642 public function process_autosave(question_attempt_pending_step $pendingstep) { 643 // If already finished. Nothing to do. 644 if ($this->qa->get_state()->is_finished()) { 645 return question_attempt::DISCARD; 646 } 647 648 // If the new data is the same as we already have, then we don't need it. 649 if ($this->is_same_response($pendingstep)) { 650 return question_attempt::DISCARD; 651 } 652 653 // Repeat that test discarding any existing autosaved data. 654 if ($this->qa->has_autosaved_step()) { 655 $this->qa->discard_autosaved_step(); 656 if ($this->is_same_response($pendingstep)) { 657 return question_attempt::DISCARD; 658 } 659 } 660 661 // OK, we need to save. 662 return $this->process_save($pendingstep); 663 } 664 665 /** 666 * Implementation of processing a save action that should be suitable for 667 * most subclasses. 668 * @param question_attempt_pending_step $pendingstep a partially initialised step 669 * containing all the information about the action that is being peformed. 670 * @return bool either {@link question_attempt::KEEP} or {@link question_attempt::DISCARD} 671 */ 672 public function process_save(question_attempt_pending_step $pendingstep) { 673 if ($this->qa->get_state()->is_finished()) { 674 return question_attempt::DISCARD; 675 } else if (!$this->qa->get_state()->is_active()) { 676 throw new coding_exception('Question is not active, cannot process_actions.'); 677 } 678 679 if ($this->is_same_response($pendingstep)) { 680 return question_attempt::DISCARD; 681 } 682 683 if ($this->is_complete_response($pendingstep)) { 684 $pendingstep->set_state(question_state::$complete); 685 } else { 686 $pendingstep->set_state(question_state::$todo); 687 } 688 return question_attempt::KEEP; 689 } 690 691 public function summarise_submit(question_attempt_step $step) { 692 return get_string('submitted', 'question', 693 $this->question->summarise_response($step->get_qt_data())); 694 } 695 696 public function summarise_save(question_attempt_step $step) { 697 $data = $step->get_submitted_data(); 698 if (empty($data)) { 699 return $this->summarise_start($step); 700 } 701 return get_string('saved', 'question', 702 $this->question->summarise_response($step->get_qt_data())); 703 } 704 705 706 public function summarise_finish($step) { 707 $data = $step->get_qt_data(); 708 if ($data) { 709 return get_string('attemptfinishedsubmitting', 'question', 710 $this->question->summarise_response($data)); 711 } 712 return get_string('attemptfinished', 'question'); 713 } 714 } 715 716 abstract class question_behaviour_with_multiple_tries extends question_behaviour_with_save { 717 public function step_has_a_submitted_response($step) { 718 return $step->has_behaviour_var('submit') && $step->get_state() != question_state::$invalid; 719 } 720 } 721 722 /** 723 * This helper class contains the constants and methods required for 724 * manipulating scores for certainty based marking. 725 * 726 * @copyright 2009 The Open University 727 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 728 */ 729 abstract class question_cbm { 730 /**#@+ @var integer named constants for the certainty levels. */ 731 const LOW = 1; 732 const MED = 2; 733 const HIGH = 3; 734 /**#@-*/ 735 736 /** @var array list of all the certainty levels. */ 737 public static $certainties = array(self::LOW, self::MED, self::HIGH); 738 739 /**#@+ @var array coefficients used to adjust the fraction based on certainty. */ 740 protected static $rightscore = array( 741 self::LOW => 1, 742 self::MED => 2, 743 self::HIGH => 3, 744 ); 745 protected static $wrongscore = array( 746 self::LOW => 0, 747 self::MED => -2, 748 self::HIGH => -6, 749 ); 750 /**#@-*/ 751 752 /**#@+ @var array upper and lower limits of the optimal window. */ 753 protected static $lowlimit = array( 754 self::LOW => 0, 755 self::MED => 0.666666666666667, 756 self::HIGH => 0.8, 757 ); 758 protected static $highlimit = array( 759 self::LOW => 0.666666666666667, 760 self::MED => 0.8, 761 self::HIGH => 1, 762 ); 763 /**#@-*/ 764 765 /** 766 * @return int the default certaintly level that should be assuemd if 767 * the student does not choose one. 768 */ 769 public static function default_certainty() { 770 return self::LOW; 771 } 772 773 /** 774 * Given a fraction, and a certainty, compute the adjusted fraction. 775 * @param number $fraction the raw fraction for this question. 776 * @param int $certainty one of the certainty level constants. 777 * @return number the adjusted fraction taking the certainty into account. 778 */ 779 public static function adjust_fraction($fraction, $certainty) { 780 if ($certainty == -1) { 781 // Certainty -1 has never been used in standard Moodle, but is 782 // used in Tony-Gardiner Medwin's patches to mean 'No idea' which 783 // we intend to implement: MDL-42077. In the mean time, avoid 784 // errors for people who have used TGM's patches. 785 return 0; 786 } 787 if ($fraction <= question_utils::MARK_TOLERANCE) { 788 return self::$wrongscore[$certainty]; 789 } else { 790 return self::$rightscore[$certainty] * $fraction; 791 } 792 } 793 794 /** 795 * @param int $certainty one of the LOW/MED/HIGH constants. 796 * @return string a textual description of this certainty. 797 */ 798 public static function get_string($certainty) { 799 return get_string('certainty' . $certainty, 'qbehaviour_deferredcbm'); 800 } 801 802 /** 803 * @param int $certainty one of the LOW/MED/HIGH constants. 804 * @return string a short textual description of this certainty. 805 */ 806 public static function get_short_string($certainty) { 807 return get_string('certaintyshort' . $certainty, 'qbehaviour_deferredcbm'); 808 } 809 810 /** 811 * Add information about certainty to a response summary. 812 * @param string $summary the response summary. 813 * @param int $certainty the level of certainty to add. 814 * @return string the summary with information about the certainty added. 815 */ 816 public static function summary_with_certainty($summary, $certainty) { 817 if (is_null($certainty)) { 818 return $summary; 819 } 820 return $summary . ' [' . self::get_short_string($certainty) . ']'; 821 } 822 823 /** 824 * @param int $certainty one of the LOW/MED/HIGH constants. 825 * @return float the lower limit of the optimal probability range for this certainty. 826 */ 827 public static function optimal_probablility_low($certainty) { 828 return self::$lowlimit[$certainty]; 829 } 830 831 /** 832 * @param int $certainty one of the LOW/MED/HIGH constants. 833 * @return float the upper limit of the optimal probability range for this certainty. 834 */ 835 public static function optimal_probablility_high($certainty) { 836 return self::$highlimit[$certainty]; 837 } 838 }
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