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Differences Between: [Versions 39 and 310] [Versions 39 and 311] [Versions 39 and 400] [Versions 39 and 401] [Versions 39 and 402] [Versions 39 and 403]

   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   * Multiple choice question definition classes.
  19   *
  20   * @package    qtype
  21   * @subpackage multichoice
  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  require_once($CFG->dirroot . '/question/type/questionbase.php');
  30  
  31  /**
  32   * Base class for multiple choice questions. The parts that are common to
  33   * single select and multiple select.
  34   *
  35   * @copyright  2009 The Open University
  36   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  37   */
  38  abstract class qtype_multichoice_base extends question_graded_automatically {
  39      const LAYOUT_DROPDOWN = 0;
  40      const LAYOUT_VERTICAL = 1;
  41      const LAYOUT_HORIZONTAL = 2;
  42  
  43      public $answers;
  44  
  45      public $shuffleanswers;
  46      public $answernumbering;
  47      /**
  48       * @var int standard instruction to be displayed if enabled.
  49       */
  50      public $showstandardinstruction = 0;
  51      public $layout = self::LAYOUT_VERTICAL;
  52  
  53      public $correctfeedback;
  54      public $correctfeedbackformat;
  55      public $partiallycorrectfeedback;
  56      public $partiallycorrectfeedbackformat;
  57      public $incorrectfeedback;
  58      public $incorrectfeedbackformat;
  59  
  60      protected $order = null;
  61  
  62      public function start_attempt(question_attempt_step $step, $variant) {
  63          $this->order = array_keys($this->answers);
  64          if ($this->shuffleanswers) {
  65              shuffle($this->order);
  66          }
  67          $step->set_qt_var('_order', implode(',', $this->order));
  68      }
  69  
  70      public function apply_attempt_state(question_attempt_step $step) {
  71          $this->order = explode(',', $step->get_qt_var('_order'));
  72  
  73          // Add any missing answers. Sometimes people edit questions after they
  74          // have been attempted which breaks things.
  75          foreach ($this->order as $ansid) {
  76              if (isset($this->answers[$ansid])) {
  77                  continue;
  78              }
  79              $a = new stdClass();
  80              $a->id = 0;
  81              $a->answer = html_writer::span(get_string('deletedchoice', 'qtype_multichoice'),
  82                      'notifyproblem');
  83              $a->answerformat = FORMAT_HTML;
  84              $a->fraction = 0;
  85              $a->feedback = '';
  86              $a->feedbackformat = FORMAT_HTML;
  87              $this->answers[$ansid] = $this->qtype->make_answer($a);
  88              $this->answers[$ansid]->answerformat = FORMAT_HTML;
  89          }
  90      }
  91  
  92      public function get_question_summary() {
  93          $question = $this->html_to_text($this->questiontext, $this->questiontextformat);
  94          $choices = array();
  95          foreach ($this->order as $ansid) {
  96              $choices[] = $this->html_to_text($this->answers[$ansid]->answer,
  97                      $this->answers[$ansid]->answerformat);
  98          }
  99          return $question . ': ' . implode('; ', $choices);
 100      }
 101  
 102      public function get_order(question_attempt $qa) {
 103          $this->init_order($qa);
 104          return $this->order;
 105      }
 106  
 107      protected function init_order(question_attempt $qa) {
 108          if (is_null($this->order)) {
 109              $this->order = explode(',', $qa->get_step(0)->get_qt_var('_order'));
 110          }
 111      }
 112  
 113      public abstract function get_response(question_attempt $qa);
 114  
 115      public abstract function is_choice_selected($response, $value);
 116  
 117      public function check_file_access($qa, $options, $component, $filearea, $args, $forcedownload) {
 118          if ($component == 'question' && in_array($filearea,
 119                  array('correctfeedback', 'partiallycorrectfeedback', 'incorrectfeedback'))) {
 120              return $this->check_combined_feedback_file_access($qa, $options, $filearea, $args);
 121  
 122          } else if ($component == 'question' && $filearea == 'answer') {
 123              $answerid = reset($args); // Itemid is answer id.
 124              return  in_array($answerid, $this->order);
 125  
 126          } else if ($component == 'question' && $filearea == 'answerfeedback') {
 127              $answerid = reset($args); // Itemid is answer id.
 128              $response = $this->get_response($qa);
 129              $isselected = false;
 130              foreach ($this->order as $value => $ansid) {
 131                  if ($ansid == $answerid) {
 132                      $isselected = $this->is_choice_selected($response, $value);
 133                      break;
 134                  }
 135              }
 136              // Param $options->suppresschoicefeedback is a hack specific to the
 137              // oumultiresponse question type. It would be good to refactor to
 138              // avoid refering to it here.
 139              return $options->feedback && empty($options->suppresschoicefeedback) &&
 140                      $isselected;
 141  
 142          } else if ($component == 'question' && $filearea == 'hint') {
 143              return $this->check_hint_file_access($qa, $options, $args);
 144  
 145          } else {
 146              return parent::check_file_access($qa, $options, $component, $filearea,
 147                      $args, $forcedownload);
 148          }
 149      }
 150  }
 151  
 152  
 153  /**
 154   * Represents a multiple choice question where only one choice should be selected.
 155   *
 156   * @copyright  2009 The Open University
 157   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 158   */
 159  class qtype_multichoice_single_question extends qtype_multichoice_base {
 160      public function get_renderer(moodle_page $page) {
 161          return $page->get_renderer('qtype_multichoice', 'single');
 162      }
 163  
 164      public function get_min_fraction() {
 165          $minfraction = 0;
 166          foreach ($this->answers as $ans) {
 167              $minfraction = min($minfraction, $ans->fraction);
 168          }
 169          return $minfraction;
 170      }
 171  
 172      /**
 173       * Return an array of the question type variables that could be submitted
 174       * as part of a question of this type, with their types, so they can be
 175       * properly cleaned.
 176       * @return array variable name => PARAM_... constant.
 177       */
 178      public function get_expected_data() {
 179          return array('answer' => PARAM_INT);
 180      }
 181  
 182      public function summarise_response(array $response) {
 183          if (!$this->is_complete_response($response)) {
 184              return null;
 185          }
 186          $ansid = $this->order[$response['answer']];
 187          return $this->html_to_text($this->answers[$ansid]->answer,
 188                  $this->answers[$ansid]->answerformat);
 189      }
 190  
 191      public function classify_response(array $response) {
 192          if (!$this->is_complete_response($response)) {
 193              return array($this->id => question_classified_response::no_response());
 194          }
 195          $choiceid = $this->order[$response['answer']];
 196          $ans = $this->answers[$choiceid];
 197          return array($this->id => new question_classified_response($choiceid,
 198                  $this->html_to_text($ans->answer, $ans->answerformat), $ans->fraction));
 199      }
 200  
 201      public function get_correct_response() {
 202          foreach ($this->order as $key => $answerid) {
 203              if (question_state::graded_state_for_fraction(
 204                      $this->answers[$answerid]->fraction)->is_correct()) {
 205                  return array('answer' => $key);
 206              }
 207          }
 208          return array();
 209      }
 210  
 211      public function prepare_simulated_post_data($simulatedresponse) {
 212          $ansid = 0;
 213          foreach ($this->answers as $answer) {
 214              if (clean_param($answer->answer, PARAM_NOTAGS) == $simulatedresponse['answer']) {
 215                  $ansid = $answer->id;
 216              }
 217          }
 218          if ($ansid) {
 219              return array('answer' => array_search($ansid, $this->order));
 220          } else {
 221              return array();
 222          }
 223      }
 224  
 225      public function get_student_response_values_for_simulation($postdata) {
 226          if (!isset($postdata['answer'])) {
 227              return array();
 228          } else {
 229              $answer = $this->answers[$this->order[$postdata['answer']]];
 230              return array('answer' => clean_param($answer->answer, PARAM_NOTAGS));
 231          }
 232      }
 233  
 234      public function is_same_response(array $prevresponse, array $newresponse) {
 235          if (!$this->is_complete_response($prevresponse)) {
 236              $prevresponse = [];
 237          }
 238          if (!$this->is_complete_response($newresponse)) {
 239              $newresponse = [];
 240          }
 241          return question_utils::arrays_same_at_key($prevresponse, $newresponse, 'answer');
 242      }
 243  
 244      public function is_complete_response(array $response) {
 245          return array_key_exists('answer', $response) && $response['answer'] !== ''
 246                  && (string) $response['answer'] !== '-1';
 247      }
 248  
 249      public function is_gradable_response(array $response) {
 250          return $this->is_complete_response($response);
 251      }
 252  
 253      public function grade_response(array $response) {
 254          if (array_key_exists('answer', $response) &&
 255                  array_key_exists($response['answer'], $this->order)) {
 256              $fraction = $this->answers[$this->order[$response['answer']]]->fraction;
 257          } else {
 258              $fraction = 0;
 259          }
 260          return array($fraction, question_state::graded_state_for_fraction($fraction));
 261      }
 262  
 263      public function get_validation_error(array $response) {
 264          if ($this->is_gradable_response($response)) {
 265              return '';
 266          }
 267          return get_string('pleaseselectananswer', 'qtype_multichoice');
 268      }
 269  
 270      public function get_response(question_attempt $qa) {
 271          return $qa->get_last_qt_var('answer', -1);
 272      }
 273  
 274      public function is_choice_selected($response, $value) {
 275          return (string) $response === (string) $value;
 276      }
 277  }
 278  
 279  
 280  /**
 281   * Represents a multiple choice question where multiple choices can be selected.
 282   *
 283   * @copyright  2009 The Open University
 284   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 285   */
 286  class qtype_multichoice_multi_question extends qtype_multichoice_base {
 287      public function get_renderer(moodle_page $page) {
 288          return $page->get_renderer('qtype_multichoice', 'multi');
 289      }
 290  
 291      public function get_min_fraction() {
 292          return 0;
 293      }
 294  
 295      public function clear_wrong_from_response(array $response) {
 296          foreach ($this->order as $key => $ans) {
 297              if (array_key_exists($this->field($key), $response) &&
 298                      question_state::graded_state_for_fraction(
 299                      $this->answers[$ans]->fraction)->is_incorrect()) {
 300                  $response[$this->field($key)] = 0;
 301              }
 302          }
 303          return $response;
 304      }
 305  
 306      public function get_num_parts_right(array $response) {
 307          $numright = 0;
 308          foreach ($this->order as $key => $ans) {
 309              $fieldname = $this->field($key);
 310              if (!array_key_exists($fieldname, $response) || !$response[$fieldname]) {
 311                  continue;
 312              }
 313  
 314              if (!question_state::graded_state_for_fraction(
 315                      $this->answers[$ans]->fraction)->is_incorrect()) {
 316                  $numright += 1;
 317              }
 318          }
 319          return array($numright, count($this->order));
 320      }
 321  
 322      /**
 323       * @param int $key choice number
 324       * @return string the question-type variable name.
 325       */
 326      protected function field($key) {
 327          return 'choice' . $key;
 328      }
 329  
 330      public function get_expected_data() {
 331          $expected = array();
 332          foreach ($this->order as $key => $notused) {
 333              $expected[$this->field($key)] = PARAM_BOOL;
 334          }
 335          return $expected;
 336      }
 337  
 338      public function summarise_response(array $response) {
 339          $selectedchoices = array();
 340          foreach ($this->order as $key => $ans) {
 341              $fieldname = $this->field($key);
 342              if (array_key_exists($fieldname, $response) && $response[$fieldname]) {
 343                  $selectedchoices[] = $this->html_to_text($this->answers[$ans]->answer,
 344                          $this->answers[$ans]->answerformat);
 345              }
 346          }
 347          if (empty($selectedchoices)) {
 348              return null;
 349          }
 350          return implode('; ', $selectedchoices);
 351      }
 352  
 353      public function classify_response(array $response) {
 354          $selectedchoices = array();
 355          foreach ($this->order as $key => $ansid) {
 356              $fieldname = $this->field($key);
 357              if (array_key_exists($fieldname, $response) && $response[$fieldname]) {
 358                  $selectedchoices[$ansid] = 1;
 359              }
 360          }
 361          $choices = array();
 362          foreach ($this->answers as $ansid => $ans) {
 363              if (isset($selectedchoices[$ansid])) {
 364                  $choices[$ansid] = new question_classified_response($ansid,
 365                          $this->html_to_text($ans->answer, $ans->answerformat), $ans->fraction);
 366              }
 367          }
 368          return $choices;
 369      }
 370  
 371      public function get_correct_response() {
 372          $response = array();
 373          foreach ($this->order as $key => $ans) {
 374              if (!question_state::graded_state_for_fraction(
 375                      $this->answers[$ans]->fraction)->is_incorrect()) {
 376                  $response[$this->field($key)] = 1;
 377              }
 378          }
 379          return $response;
 380      }
 381  
 382      public function prepare_simulated_post_data($simulatedresponse) {
 383          $postdata = array();
 384          foreach ($simulatedresponse as $ans => $checked) {
 385              foreach ($this->answers as $ansid => $answer) {
 386                  if (clean_param($answer->answer, PARAM_NOTAGS) == $ans) {
 387                      $fieldno = array_search($ansid, $this->order);
 388                      $postdata[$this->field($fieldno)] = $checked;
 389                      break;
 390                  }
 391              }
 392          }
 393          return $postdata;
 394      }
 395  
 396      public function get_student_response_values_for_simulation($postdata) {
 397          $simulatedresponse = array();
 398          foreach ($this->order as $fieldno => $ansid) {
 399              if (isset($postdata[$this->field($fieldno)])) {
 400                  $checked = $postdata[$this->field($fieldno)];
 401                  $simulatedresponse[clean_param($this->answers[$ansid]->answer, PARAM_NOTAGS)] = $checked;
 402              }
 403          }
 404          ksort($simulatedresponse);
 405          return $simulatedresponse;
 406      }
 407  
 408      public function is_same_response(array $prevresponse, array $newresponse) {
 409          foreach ($this->order as $key => $notused) {
 410              $fieldname = $this->field($key);
 411              if (!question_utils::arrays_same_at_key_integer($prevresponse, $newresponse, $fieldname)) {
 412                  return false;
 413              }
 414          }
 415          return true;
 416      }
 417  
 418      public function is_complete_response(array $response) {
 419          foreach ($this->order as $key => $notused) {
 420              if (!empty($response[$this->field($key)])) {
 421                  return true;
 422              }
 423          }
 424          return false;
 425      }
 426  
 427      public function is_gradable_response(array $response) {
 428          return $this->is_complete_response($response);
 429      }
 430  
 431      /**
 432       * @param array $response responses, as returned by
 433       *      {@link question_attempt_step::get_qt_data()}.
 434       * @return int the number of choices that were selected. in this response.
 435       */
 436      public function get_num_selected_choices(array $response) {
 437          $numselected = 0;
 438          foreach ($response as $key => $value) {
 439              // Response keys starting with _ are internal values like _order, so ignore them.
 440              if (!empty($value) && $key[0] != '_') {
 441                  $numselected += 1;
 442              }
 443          }
 444          return $numselected;
 445      }
 446  
 447      /**
 448       * @return int the number of choices that are correct.
 449       */
 450      public function get_num_correct_choices() {
 451          $numcorrect = 0;
 452          foreach ($this->answers as $ans) {
 453              if (!question_state::graded_state_for_fraction($ans->fraction)->is_incorrect()) {
 454                  $numcorrect += 1;
 455              }
 456          }
 457          return $numcorrect;
 458      }
 459  
 460      public function grade_response(array $response) {
 461          $fraction = 0;
 462          foreach ($this->order as $key => $ansid) {
 463              if (!empty($response[$this->field($key)])) {
 464                  $fraction += $this->answers[$ansid]->fraction;
 465              }
 466          }
 467          $fraction = min(max(0, $fraction), 1.0);
 468          return array($fraction, question_state::graded_state_for_fraction($fraction));
 469      }
 470  
 471      public function get_validation_error(array $response) {
 472          if ($this->is_gradable_response($response)) {
 473              return '';
 474          }
 475          return get_string('pleaseselectatleastoneanswer', 'qtype_multichoice');
 476      }
 477  
 478      /**
 479       * Disable those hint settings that we don't want when the student has selected
 480       * more choices than the number of right choices. This avoids giving the game away.
 481       * @param question_hint_with_parts $hint a hint.
 482       */
 483      protected function disable_hint_settings_when_too_many_selected(
 484              question_hint_with_parts $hint) {
 485          $hint->clearwrong = false;
 486      }
 487  
 488      public function get_hint($hintnumber, question_attempt $qa) {
 489          $hint = parent::get_hint($hintnumber, $qa);
 490          if (is_null($hint)) {
 491              return $hint;
 492          }
 493  
 494          if ($this->get_num_selected_choices($qa->get_last_qt_data()) >
 495                  $this->get_num_correct_choices()) {
 496              $hint = clone($hint);
 497              $this->disable_hint_settings_when_too_many_selected($hint);
 498          }
 499          return $hint;
 500      }
 501  
 502      public function get_response(question_attempt $qa) {
 503          return $qa->get_last_qt_data();
 504      }
 505  
 506      public function is_choice_selected($response, $value) {
 507          return !empty($response['choice' . $value]);
 508      }
 509  }