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Differences Between: [Versions 310 and 311] [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   * Base class for editing question types like this one.
  19   *
  20   * @package    qtype_gapselect
  21   * @copyright  2011 The Open University
  22   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  defined('MOODLE_INTERNAL') || die();
  26  
  27  
  28  /**
  29   * Elements embedded in question text editing form definition.
  30   *
  31   * @copyright  2011 The Open University
  32   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  33   */
  34  class qtype_gapselect_edit_form_base extends question_edit_form {
  35  
  36      /** @var array of HTML tags allowed in choices / drag boxes. */
  37      protected $allowedhtmltags = array(
  38          'sub',
  39          'sup',
  40          'b',
  41          'i',
  42          'em',
  43          'strong',
  44          'span',
  45      );
  46  
  47      /** @var string regex to match HTML open tags. */
  48      private $htmltstarttagsandattributes = '~<\s*\w+\b[^>]*>~';
  49  
  50      /** @var string regex to match HTML close tags or br. */
  51      private $htmltclosetags = '~<\s*/\s*\w+\b[^>]*>~';
  52  
  53      /** @var string regex to select text like [[cat]] (including the square brackets). */
  54      private $squarebracketsregex = '/\[\[[^]]*?\]\]/';
  55  
  56      /**
  57       * Vaidate some input to make sure it does not contain any tags other than
  58       * $this->allowedhtmltags.
  59       * @param string $text the input to validate.
  60       * @return string any validation errors.
  61       */
  62      protected function get_illegal_tag_error($text) {
  63          // Remove legal tags.
  64          $strippedtext = $text;
  65          foreach ($this->allowedhtmltags as $htmltag) {
  66              $tagpair = "~<\s*/?\s*$htmltag\b\s*[^>]*>~";
  67              $strippedtext = preg_replace($tagpair, '', $strippedtext);
  68          }
  69  
  70          $textarray = array();
  71          preg_match_all($this->htmltstarttagsandattributes, $strippedtext, $textarray);
  72          if ($textarray[0]) {
  73              return $this->allowed_tags_message($textarray[0][0]);
  74          }
  75  
  76          preg_match_all($this->htmltclosetags, $strippedtext, $textarray);
  77          if ($textarray[0]) {
  78              return $this->allowed_tags_message($textarray[0][0]);
  79          }
  80  
  81          return '';
  82      }
  83  
  84      /**
  85       * Returns a message indicating what tags are allowed.
  86       *
  87       * @param string $badtag The disallowed tag that was supplied
  88       * @return string Message indicating what tags are allowed
  89       */
  90      private function allowed_tags_message($badtag) {
  91          $a = new stdClass();
  92          $a->tag = htmlspecialchars($badtag);
  93          $a->allowed = $this->get_list_of_printable_allowed_tags($this->allowedhtmltags);
  94          if ($a->allowed) {
  95              return get_string('tagsnotallowed', 'qtype_gapselect', $a);
  96          } else {
  97              return get_string('tagsnotallowedatall', 'qtype_gapselect', $a);
  98          }
  99      }
 100  
 101      /**
 102       * Returns a prinatble list of allowed HTML tags.
 103       *
 104       * @param array $allowedhtmltags An array for tag strings that are allowed
 105       * @return string A printable list of tags
 106       */
 107      private function get_list_of_printable_allowed_tags($allowedhtmltags) {
 108          $allowedtaglist = array();
 109          foreach ($allowedhtmltags as $htmltag) {
 110              $allowedtaglist[] = htmlspecialchars('<' . $htmltag . '>');
 111          }
 112          return implode(', ', $allowedtaglist);
 113      }
 114  
 115      /**
 116       * definition_inner adds all specific fields to the form.
 117       * @param object $mform (the form being built).
 118       */
 119      protected function definition_inner($mform) {
 120          global $CFG;
 121  
 122          // Add the answer (choice) fields to the form.
 123          $this->definition_answer_choice($mform);
 124  
 125          $this->add_combined_feedback_fields(true);
 126          $this->add_interactive_settings(true, true);
 127      }
 128  
 129      /**
 130       * Defines form elements for answer choices.
 131       *
 132       * @param object $mform The Moodle form object being built
 133       */
 134      protected function definition_answer_choice(&$mform) {
 135          $mform->addElement('header', 'choicehdr', get_string('choices', 'qtype_gapselect'));
 136          $mform->setExpanded('choicehdr', 1);
 137  
 138          $mform->addElement('checkbox', 'shuffleanswers', get_string('shuffle', 'qtype_gapselect'));
 139          $mform->setDefault('shuffleanswers', $this->get_default_value('shuffleanswers', 0));
 140  
 141          $textboxgroup = array();
 142          $textboxgroup[] = $mform->createElement('group', 'choices',
 143                  get_string('choicex', 'qtype_gapselect'), $this->choice_group($mform));
 144  
 145          if (!empty($this->question->options->answers)) {
 146              $repeatsatstart = count($this->question->options->answers);
 147          } else {
 148              $repeatsatstart = QUESTION_NUMANS_ADD * 2;
 149          }
 150  
 151          $repeatedoptions = $this->repeated_options();
 152          $mform->setType('answer', PARAM_RAW);
 153          $this->repeat_elements($textboxgroup, $repeatsatstart, $repeatedoptions,
 154                  'noanswers', 'addanswers', QUESTION_NUMANS_ADD,
 155                  get_string('addmorechoiceblanks', 'qtype_gapselect'), true);
 156      }
 157  
 158      /**
 159       * Return how many different groups of choices there should be.
 160       *
 161       * @return int the maximum group number.
 162       */
 163      function get_maximum_choice_group_number() {
 164          return 8;
 165      }
 166  
 167      /**
 168       * Creates an array with elements for a choice group.
 169       *
 170       * @param object $mform The Moodle form we are working with
 171       * @param int $maxgroup The number of max group generate element select.
 172       * @return array Array for form elements
 173       */
 174      protected function choice_group($mform) {
 175          $options = array();
 176          for ($i = 1; $i <= $this->get_maximum_choice_group_number(); $i += 1) {
 177              $options[$i] = question_utils::int_to_letter($i);
 178          }
 179          $grouparray = array();
 180          $grouparray[] = $mform->createElement('text', 'answer',
 181                  get_string('answer', 'qtype_gapselect'), array('size' => 30, 'class' => 'tweakcss'));
 182          $grouparray[] = $mform->createElement('select', 'choicegroup',
 183                  get_string('group', 'qtype_gapselect'), $options);
 184          return $grouparray;
 185      }
 186  
 187      /**
 188       * Returns an array for form repeat options.
 189       *
 190       * @return array Array of repeate options
 191       */
 192      protected function repeated_options() {
 193          $repeatedoptions = array();
 194          $repeatedoptions['choicegroup']['default'] = '1';
 195          $repeatedoptions['choices[answer]']['type'] = PARAM_RAW;
 196          return $repeatedoptions;
 197      }
 198  
 199      public function data_preprocessing($question) {
 200          $question = parent::data_preprocessing($question);
 201          $question = $this->data_preprocessing_combined_feedback($question, true);
 202          $question = $this->data_preprocessing_hints($question, true, true);
 203  
 204          $question = $this->data_preprocessing_answers($question, true);
 205          if (!empty($question->options->answers)) {
 206              $key = 0;
 207              foreach ($question->options->answers as $answer) {
 208                  $question = $this->data_preprocessing_choice($question, $answer, $key);
 209                  $key++;
 210              }
 211          }
 212  
 213          if (!empty($question->options)) {
 214              $question->shuffleanswers = $question->options->shuffleanswers;
 215          }
 216  
 217          return $question;
 218      }
 219  
 220      protected function data_preprocessing_choice($question, $answer, $key) {
 221          $question->choices[$key]['answer'] = $answer->answer;
 222          $question->choices[$key]['choicegroup'] = $answer->feedback;
 223          return $question;
 224      }
 225  
 226      public function validation($data, $files) {
 227          $errors = parent::validation($data, $files);
 228          $questiontext = $data['questiontext'];
 229          $choices = $data['choices'];
 230  
 231          // Check the whether the slots are valid.
 232          $errorsinquestiontext = $this->validate_slots($questiontext['text'], $choices);
 233          if ($errorsinquestiontext) {
 234              $errors['questiontext'] = $errorsinquestiontext;
 235          }
 236          foreach ($choices as $key => $choice) {
 237              $answer = $choice['answer'];
 238  
 239              // Check whether the HTML tags are allowed tags.
 240              $tagerror = $this->get_illegal_tag_error($answer);
 241              if ($tagerror) {
 242                  $errors['choices['.$key.']'] = $tagerror;
 243              }
 244          }
 245          return $errors;
 246      }
 247  
 248      /**
 249       * Finds errors in question slots.
 250       *
 251       * @param string $questiontext The question text
 252       * @param array $choices Question choices
 253       * @return string|bool Error message or false if no errors
 254       */
 255      private function validate_slots($questiontext, $choices) {
 256          $error = 'Please check the Question text: ';
 257          if (!$questiontext) {
 258              return get_string('errorquestiontextblank', 'qtype_gapselect');
 259          }
 260  
 261          $matches = array();
 262          preg_match_all($this->squarebracketsregex, $questiontext, $matches);
 263          $slots = $matches[0];
 264  
 265          if (!$slots) {
 266              return get_string('errornoslots', 'qtype_gapselect');
 267          }
 268  
 269          $cleanedslots = array();
 270          foreach ($slots as $slot) {
 271              // The 2 is for'[[' and 4 is for '[[]]'.
 272              $cleanedslots[] = substr($slot, 2, (strlen($slot) - 4));
 273          }
 274          $slots = $cleanedslots;
 275  
 276          foreach ($slots as $slot) {
 277              $found = false;
 278              foreach ($choices as $key => $choice) {
 279                  if ($slot == $key + 1) {
 280                      if ($choice['answer'] === '') {
 281                          return get_string('errorblankchoice', 'qtype_gapselect',
 282                                  html_writer::tag('b', $slot));
 283                      }
 284                      $found = true;
 285                      break;
 286                  }
 287              }
 288              if (!$found) {
 289                  return get_string('errormissingchoice', 'qtype_gapselect',
 290                          html_writer::tag('b', $slot));
 291              }
 292          }
 293          return $this->extra_slot_validation($slots, $choices) ?? false;
 294      }
 295  
 296      public function qtype() {
 297          return '';
 298      }
 299  
 300      /**
 301       * Finds more errors in question slots.
 302       *
 303       * @param array $slots The question text
 304       * @param array $choices Question choices
 305       * @return string|null Error message or false if no errors
 306       */
 307      protected function extra_slot_validation(array $slots, array $choices): ?string {
 308          return null;
 309      }
 310  }