[Summary view]

   1  <?php
   2  
   3  // This file is part of Moodle - http://moodle.org/
   4  //
   5  // Moodle is free software: you can redistribute it and/or modify
   6  // it under the terms of the GNU General Public License as published by
   7  // the Free Software Foundation, either version 3 of the License, or
   8  // (at your option) any later version.
   9  //
  10  // Moodle is distributed in the hope that it will be useful,
  11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  // GNU General Public License for more details.
  14  //
  15  // You should have received a copy of the GNU General Public License
  16  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17  
  18  /**
  19   * Filter converting emoticon texts into images
  20   *
  21   * This filter uses the emoticon settings in Site admin > Appearance > HTML settings
  22   * and replaces emoticon texts with images.
  23   *
  24   * @package    filter
  25   * @subpackage emoticon
  26   * @see        emoticon_manager
  27   * @copyright  2010 David Mudrak <david@moodle.com>
  28   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  29   */
  30  
  31  defined('MOODLE_INTERNAL') || die();
  32  
  33  class filter_emoticon extends moodle_text_filter {
  34  
  35      /**
  36       * Internal cache used for replacing. Multidimensional array;
  37       * - dimension 1: language,
  38       * - dimension 2: theme.
  39       * @var array
  40       */
  41      protected static $emoticontexts = array();
  42  
  43      /**
  44       * Internal cache used for replacing. Multidimensional array;
  45       * - dimension 1: language,
  46       * - dimension 2: theme.
  47       * @var array
  48       */
  49      protected static $emoticonimgs = array();
  50  
  51      /**
  52       * Apply the filter to the text
  53       *
  54       * @see filter_manager::apply_filter_chain()
  55       * @param string $text to be processed by the text
  56       * @param array $options filter options
  57       * @return string text after processing
  58       */
  59      public function filter($text, array $options = array()) {
  60  
  61          if (!isset($options['originalformat'])) {
  62              // if the format is not specified, we are probably called by {@see format_string()}
  63              // in that case, it would be dangerous to replace text with the image because it could
  64              // be stripped. therefore, we do nothing
  65              return $text;
  66          }
  67          if (in_array($options['originalformat'], explode(',', get_config('filter_emoticon', 'formats')))) {
  68              return $this->replace_emoticons($text);
  69          }
  70          return $text;
  71      }
  72  
  73      ////////////////////////////////////////////////////////////////////////////
  74      // internal implementation starts here
  75      ////////////////////////////////////////////////////////////////////////////
  76  
  77      /**
  78       * Replace emoticons found in the text with their images
  79       *
  80       * @param string $text to modify
  81       * @return string the modified result
  82       */
  83      protected function replace_emoticons($text) {
  84          global $CFG, $OUTPUT, $PAGE;
  85  
  86          $lang = current_language();
  87          $theme = $PAGE->theme->name;
  88  
  89          if (!isset(self::$emoticontexts[$lang][$theme]) or !isset(self::$emoticonimgs[$lang][$theme])) {
  90              // prepare internal caches
  91              $manager = get_emoticon_manager();
  92              $emoticons = $manager->get_emoticons();
  93              self::$emoticontexts[$lang][$theme] = array();
  94              self::$emoticonimgs[$lang][$theme] = array();
  95              foreach ($emoticons as $emoticon) {
  96                  self::$emoticontexts[$lang][$theme][] = $emoticon->text;
  97                  self::$emoticonimgs[$lang][$theme][] = $OUTPUT->render($manager->prepare_renderable_emoticon($emoticon));
  98              }
  99              unset($emoticons);
 100          }
 101  
 102          if (empty(self::$emoticontexts[$lang][$theme])) { // No emoticons defined, nothing to process here.
 103              return $text;
 104          }
 105  
 106          // Detect all zones that we should not handle (including the nested tags).
 107          $processing = preg_split('/(<\/?(?:span|script|pre)[^>]*>)/is', $text, 0, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
 108  
 109          // Initialize the results.
 110          $resulthtml = "";
 111          $exclude = 0;
 112  
 113          // Define the patterns that mark the start of the forbidden zones.
 114          $excludepattern = array('/^<script/is', '/^<span[^>]+class="nolink[^"]*"/is', '/^<pre/is');
 115  
 116          // Loop through the fragments.
 117          foreach ($processing as $fragment) {
 118              // If we are not ignoring, we MUST test if we should.
 119              if ($exclude == 0) {
 120                  foreach ($excludepattern as $exp) {
 121                      if (preg_match($exp, $fragment)) {
 122                          $exclude = $exclude + 1;
 123                          break;
 124                      }
 125                  }
 126              }
 127              if ($exclude > 0) {
 128                  // If we are ignoring the fragment, then we must check if we may have reached the end of the zone.
 129                  if (strpos($fragment, '</span') !== false || strpos($fragment, '</script') !== false
 130                      || strpos($fragment, '</pre') !== false) {
 131                      $exclude -= 1;
 132                      // This is needed because of a double increment at the first element.
 133                      if ($exclude == 1) {
 134                          $exclude -= 1;
 135                      }
 136                  } else if (strpos($fragment, '<span') !== false || strpos($fragment, '<script') !== false
 137                      || strpos($fragment, '<pre') !== false) {
 138                      // If we find a nested tag we increase the exclusion level.
 139                      $exclude = $exclude + 1;
 140                  }
 141              } else if (strpos($fragment, '<span') === false ||
 142                         strpos($fragment, '</span') === false) {
 143                  // This is the meat of the code - this is run every time.
 144                  // This code only runs for fragments that are not ignored (including the tags themselves).
 145                  $fragment = str_replace(self::$emoticontexts[$lang][$theme], self::$emoticonimgs[$lang][$theme], $fragment);
 146              }
 147              $resulthtml .= $fragment;
 148          }
 149  
 150          return $resulthtml;
 151      }
 152  }