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

   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   * Matching question definition class.
  19   *
  20   * @package   qtype_match
  21   * @copyright 2009 The Open University
  22   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  
  26  defined('MOODLE_INTERNAL') || die();
  27  
  28  require_once($CFG->dirroot . '/question/type/questionbase.php');
  29  
  30  /**
  31   * Represents a matching question.
  32   *
  33   * @copyright 2009 The Open University
  34   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  35   */
  36  class qtype_match_question extends question_graded_automatically_with_countback {
  37      /** @var boolean Whether the question stems should be shuffled. */
  38      public $shufflestems;
  39  
  40      public $correctfeedback;
  41      public $correctfeedbackformat;
  42      public $partiallycorrectfeedback;
  43      public $partiallycorrectfeedbackformat;
  44      public $incorrectfeedback;
  45      public $incorrectfeedbackformat;
  46  
  47      /** @var array of question stems. */
  48      public $stems;
  49      /** @var int[] FORMAT_... type for each stem. */
  50      public $stemformat;
  51      /** @var array of choices that can be matched to each stem. */
  52      public $choices;
  53      /** @var array index of the right choice for each stem. */
  54      public $right;
  55  
  56      /** @var array shuffled stem indexes. */
  57      protected $stemorder;
  58      /** @var array shuffled choice indexes. */
  59      protected $choiceorder;
  60  
  61      public function start_attempt(question_attempt_step $step, $variant) {
  62          $this->stemorder = array_keys($this->stems);
  63          if ($this->shufflestems) {
  64              shuffle($this->stemorder);
  65          }
  66          $step->set_qt_var('_stemorder', implode(',', $this->stemorder));
  67  
  68          $choiceorder = array_keys($this->choices);
  69          shuffle($choiceorder);
  70          $step->set_qt_var('_choiceorder', implode(',', $choiceorder));
  71          $this->set_choiceorder($choiceorder);
  72      }
  73  
  74      public function apply_attempt_state(question_attempt_step $step) {
  75          $this->stemorder = explode(',', $step->get_qt_var('_stemorder'));
  76          $this->set_choiceorder(explode(',', $step->get_qt_var('_choiceorder')));
  77  
  78          // Add any missing subquestions. Sometimes people edit questions after they
  79          // have been attempted which breaks things.
  80          foreach ($this->stemorder as $stemid) {
  81              if (!isset($this->stems[$stemid])) {
  82                  $this->stems[$stemid] = html_writer::span(
  83                          get_string('deletedsubquestion', 'qtype_match'), 'notifyproblem');
  84                  $this->stemformat[$stemid] = FORMAT_HTML;
  85                  $this->right[$stemid] = 0;
  86              }
  87          }
  88  
  89          // Add any missing choices. Sometimes people edit questions after they
  90          // have been attempted which breaks things.
  91          foreach ($this->choiceorder as $choiceid) {
  92              if (!isset($this->choices[$choiceid])) {
  93                  $this->choices[$choiceid] = get_string('deletedchoice', 'qtype_match');
  94              }
  95          }
  96      }
  97  
  98      /**
  99       * Helper method used by both {@link start_attempt()} and
 100       * {@link apply_attempt_state()}.
 101       * @param array $choiceorder the choices, in order.
 102       */
 103      protected function set_choiceorder($choiceorder) {
 104          $this->choiceorder = array();
 105          foreach ($choiceorder as $key => $choiceid) {
 106              $this->choiceorder[$key + 1] = $choiceid;
 107          }
 108      }
 109  
 110      public function get_question_summary() {
 111          $question = $this->html_to_text($this->questiontext, $this->questiontextformat);
 112          $stems = array();
 113          foreach ($this->stemorder as $stemid) {
 114              $stems[] = $this->html_to_text($this->stems[$stemid], $this->stemformat[$stemid]);
 115          }
 116          $choices = array();
 117          foreach ($this->choiceorder as $choiceid) {
 118              $choices[] = $this->choices[$choiceid];
 119          }
 120          return $question . ' {' . implode('; ', $stems) . '} -> {' .
 121                  implode('; ', $choices) . '}';
 122      }
 123  
 124      public function summarise_response(array $response) {
 125          $matches = array();
 126          foreach ($this->stemorder as $key => $stemid) {
 127              if (array_key_exists($this->field($key), $response) && $response[$this->field($key)]) {
 128                  $matches[] = $this->html_to_text($this->stems[$stemid],
 129                          $this->stemformat[$stemid]) . ' -> ' .
 130                          $this->choices[$this->choiceorder[$response[$this->field($key)]]];
 131              }
 132          }
 133          if (empty($matches)) {
 134              return null;
 135          }
 136          return implode('; ', $matches);
 137      }
 138  
 139      public function classify_response(array $response) {
 140          $selectedchoicekeys = array();
 141          foreach ($this->stemorder as $key => $stemid) {
 142              if (array_key_exists($this->field($key), $response) && $response[$this->field($key)]) {
 143                  $selectedchoicekeys[$stemid] = $this->choiceorder[$response[$this->field($key)]];
 144              } else {
 145                  $selectedchoicekeys[$stemid] = 0;
 146              }
 147          }
 148  
 149          $parts = array();
 150          foreach ($this->stems as $stemid => $stem) {
 151              if ($this->right[$stemid] == 0 || !isset($selectedchoicekeys[$stemid])) {
 152                  // Choice for a deleted subquestion, ignore. (See apply_attempt_state.)
 153                  continue;
 154              }
 155              $selectedchoicekey = $selectedchoicekeys[$stemid];
 156              if (empty($selectedchoicekey)) {
 157                  $parts[$stemid] = question_classified_response::no_response();
 158                  continue;
 159              }
 160              $choice = $this->choices[$selectedchoicekey];
 161              if ($choice == get_string('deletedchoice', 'qtype_match')) {
 162                  // Deleted choice, ignore. (See apply_attempt_state.)
 163                  continue;
 164              }
 165              $parts[$stemid] = new question_classified_response(
 166                      $selectedchoicekey, $choice,
 167                      ($selectedchoicekey == $this->right[$stemid]) / count($this->stems));
 168          }
 169          return $parts;
 170      }
 171  
 172      public function clear_wrong_from_response(array $response) {
 173          foreach ($this->stemorder as $key => $stemid) {
 174              if (!array_key_exists($this->field($key), $response) ||
 175                      $response[$this->field($key)] != $this->get_right_choice_for($stemid)) {
 176                  $response[$this->field($key)] = 0;
 177              }
 178          }
 179          return $response;
 180      }
 181  
 182      public function get_num_parts_right(array $response) {
 183          $numright = 0;
 184          foreach ($this->stemorder as $key => $stemid) {
 185              $fieldname = $this->field($key);
 186              if (!array_key_exists($fieldname, $response)) {
 187                  continue;
 188              }
 189  
 190              $choice = $response[$fieldname];
 191              if ($choice && $this->choiceorder[$choice] == $this->right[$stemid]) {
 192                  $numright += 1;
 193              }
 194          }
 195          return array($numright, count($this->stemorder));
 196      }
 197  
 198      /**
 199       * @param int $key stem number
 200       * @return string the question-type variable name.
 201       */
 202      protected function field($key) {
 203          return 'sub' . $key;
 204      }
 205  
 206      public function get_expected_data() {
 207          $vars = array();
 208          foreach ($this->stemorder as $key => $notused) {
 209              $vars[$this->field($key)] = PARAM_INT;
 210          }
 211          return $vars;
 212      }
 213  
 214      public function get_correct_response() {
 215          $response = array();
 216          foreach ($this->stemorder as $key => $stemid) {
 217              $response[$this->field($key)] = $this->get_right_choice_for($stemid);
 218          }
 219          return $response;
 220      }
 221  
 222      public function prepare_simulated_post_data($simulatedresponse) {
 223          $postdata = array();
 224          $stemtostemids = array_flip(clean_param_array($this->stems, PARAM_NOTAGS));
 225          $choicetochoiceno = array_flip($this->choices);
 226          $choicenotochoiceselectvalue = array_flip($this->choiceorder);
 227          foreach ($simulatedresponse as $stem => $choice) {
 228              $choice = clean_param($choice, PARAM_NOTAGS);
 229              $stemid = $stemtostemids[$stem];
 230              $shuffledstemno = array_search($stemid, $this->stemorder);
 231              if (empty($choice)) {
 232                  $choiceselectvalue = 0;
 233              } else if ($choicetochoiceno[$choice]) {
 234                  $choiceselectvalue = $choicenotochoiceselectvalue[$choicetochoiceno[$choice]];
 235              } else {
 236                  throw new coding_exception("Unknown choice {$choice} in matching question - {$this->name}.");
 237              }
 238              $postdata[$this->field($shuffledstemno)] = $choiceselectvalue;
 239          }
 240          return $postdata;
 241      }
 242  
 243      public function get_student_response_values_for_simulation($postdata) {
 244          $simulatedresponse = array();
 245          foreach ($this->stemorder as $shuffledstemno => $stemid) {
 246              if (!empty($postdata[$this->field($shuffledstemno)])) {
 247                  $choiceselectvalue = $postdata[$this->field($shuffledstemno)];
 248                  $choiceno = $this->choiceorder[$choiceselectvalue];
 249                  $choice = clean_param($this->choices[$choiceno], PARAM_NOTAGS);
 250                  $stem = clean_param($this->stems[$stemid], PARAM_NOTAGS);
 251                  $simulatedresponse[$stem] = $choice;
 252              }
 253          }
 254          ksort($simulatedresponse);
 255          return $simulatedresponse;
 256      }
 257  
 258      public function get_right_choice_for($stemid) {
 259          foreach ($this->choiceorder as $choicekey => $choiceid) {
 260              if ($this->right[$stemid] == $choiceid) {
 261                  return $choicekey;
 262              }
 263          }
 264      }
 265  
 266      public function is_complete_response(array $response) {
 267          $complete = true;
 268          foreach ($this->stemorder as $key => $stemid) {
 269              $complete = $complete && !empty($response[$this->field($key)]);
 270          }
 271          return $complete;
 272      }
 273  
 274      public function is_gradable_response(array $response) {
 275          foreach ($this->stemorder as $key => $stemid) {
 276              if (!empty($response[$this->field($key)])) {
 277                  return true;
 278              }
 279          }
 280          return false;
 281      }
 282  
 283      public function get_validation_error(array $response) {
 284          if ($this->is_complete_response($response)) {
 285              return '';
 286          }
 287          return get_string('pleaseananswerallparts', 'qtype_match');
 288      }
 289  
 290      public function is_same_response(array $prevresponse, array $newresponse) {
 291          foreach ($this->stemorder as $key => $notused) {
 292              $fieldname = $this->field($key);
 293              if (!question_utils::arrays_same_at_key_integer(
 294                      $prevresponse, $newresponse, $fieldname)) {
 295                  return false;
 296              }
 297          }
 298          return true;
 299      }
 300  
 301      public function grade_response(array $response) {
 302          list($right, $total) = $this->get_num_parts_right($response);
 303          $fraction = $right / $total;
 304          return array($fraction, question_state::graded_state_for_fraction($fraction));
 305      }
 306  
 307      public function compute_final_grade($responses, $totaltries) {
 308          $totalstemscore = 0;
 309          foreach ($this->stemorder as $key => $stemid) {
 310              $fieldname = $this->field($key);
 311  
 312              $lastwrongindex = -1;
 313              $finallyright = false;
 314              foreach ($responses as $i => $response) {
 315                  if (!array_key_exists($fieldname, $response) || !$response[$fieldname] ||
 316                          $this->choiceorder[$response[$fieldname]] != $this->right[$stemid]) {
 317                      $lastwrongindex = $i;
 318                      $finallyright = false;
 319                  } else {
 320                      $finallyright = true;
 321                  }
 322              }
 323  
 324              if ($finallyright) {
 325                  $totalstemscore += max(0, 1 - ($lastwrongindex + 1) * $this->penalty);
 326              }
 327          }
 328  
 329          return $totalstemscore / count($this->stemorder);
 330      }
 331  
 332      public function get_stem_order() {
 333          return $this->stemorder;
 334      }
 335  
 336      public function get_choice_order() {
 337          return $this->choiceorder;
 338      }
 339  
 340      public function check_file_access($qa, $options, $component, $filearea, $args, $forcedownload) {
 341          if ($component == 'qtype_match' && $filearea == 'subquestion') {
 342              $subqid = reset($args); // Itemid is sub question id.
 343              return array_key_exists($subqid, $this->stems);
 344  
 345          } else if ($component == 'question' && in_array($filearea,
 346                  array('correctfeedback', 'partiallycorrectfeedback', 'incorrectfeedback'))) {
 347              return $this->check_combined_feedback_file_access($qa, $options, $filearea, $args);
 348  
 349          } else if ($component == 'question' && $filearea == 'hint') {
 350              return $this->check_hint_file_access($qa, $options, $args);
 351  
 352          } else {
 353              return parent::check_file_access($qa, $options, $component, $filearea,
 354                      $args, $forcedownload);
 355          }
 356      }
 357  
 358      /**
 359       * Return the question settings that define this question as structured data.
 360       *
 361       * @param question_attempt $qa the current attempt for which we are exporting the settings.
 362       * @param question_display_options $options the question display options which say which aspects of the question
 363       * should be visible.
 364       * @return mixed structure representing the question settings. In web services, this will be JSON-encoded.
 365       */
 366      public function get_question_definition_for_external_rendering(question_attempt $qa, question_display_options $options) {
 367          // This is a partial implementation, returning only the most relevant question settings for now,
 368          // ideally, we should return as much as settings as possible (depending on the state and display options).
 369  
 370          return [
 371              'shufflestems' => $this->shufflestems,
 372          ];
 373      }
 374  }