filter/emoticon/filter.php

   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      * @var array global configuration for this filter
  37      *
  38      * This might be eventually moved into parent class if we found it
  39      * useful for other filters, too.
  40      */
  41     protected static $globalconfig;
  42
  43     /**
  44      * Apply the filter to the text
  45      *
  46      * @see filter_manager::apply_filter_chain()
  47      * @param string $text to be processed by the text
  48      * @param array $options filter options
  49      * @return string text after processing
  50      */
  51     public function filter($text, array $options = array()) {
  52
  53         if (!isset($options['originalformat'])) {
  54             // if the format is not specified, we are probably called by {@see format_string()}
  55             // in that case, it would be dangerous to replace text with the image because it could
  56             // be stripped. therefore, we do nothing
  57             return $text;
  58         }
  59         if (in_array($options['originalformat'], explode(',', $this->get_global_config('formats')))) {
  60             $this->replace_emoticons($text);
  61         }
  62         return $text;
  63     }
  64
  65     ////////////////////////////////////////////////////////////////////////////
  66     // internal implementation starts here
  67     ////////////////////////////////////////////////////////////////////////////
  68
  69     /**
  70      * Returns the global filter setting
  71      *
  72      * If the $name is provided, returns single value. Otherwise returns all
  73      * global settings in object. Returns null if the named setting is not
  74      * found.
  75      *
  76      * @param mixed $name optional config variable name, defaults to null for all
  77      * @return string|object|null
  78      */
  79     protected function get_global_config($name=null) {
  80         $this->load_global_config();
  81         if (is_null($name)) {
  82             return self::$globalconfig;
  83
  84         } elseif (array_key_exists($name, self::$globalconfig)) {
  85             return self::$globalconfig->{$name};
  86
  87         } else {
  88             return null;
  89         }
  90     }
  91
  92     /**
  93      * Makes sure that the global config is loaded in $this->globalconfig
  94      *
  95      * @return void
  96      */
  97     protected function load_global_config() {
  98         if (is_null(self::$globalconfig)) {
  99             self::$globalconfig = get_config('filter_emoticon');
 100         }
 101     }
 102
 103     /**
 104      * Replace emoticons found in the text with their images
 105      *
 106      * @param string $text to modify
 107      * @return void
 108      */
 109     protected function replace_emoticons(&$text) {
 110         global $CFG, $OUTPUT, $PAGE;
 111         static $emoticontexts = array();    // internal cache used for replacing
 112         static $emoticonimgs = array();     // internal cache used for replacing
 113
 114         $lang = current_language();
 115         $theme = $PAGE->theme->name;
 116
 117         if (!isset($emoticontexts[$lang][$theme]) or !isset($emoticonimgs[$lang][$theme])) {
 118             // prepare internal caches
 119             $manager = get_emoticon_manager();
 120             $emoticons = $manager->get_emoticons();
 121             $emoticontexts[$lang][$theme] = array();
 122             $emoticonimgs[$lang][$theme] = array();
 123             foreach ($emoticons as $emoticon) {
 124                 $emoticontexts[$lang][$theme][] = $emoticon->text;
 125                 $emoticonimgs[$lang][$theme][] = $OUTPUT->render($manager->prepare_renderable_emoticon($emoticon));
 126             }
 127             unset($emoticons);
 128         }
 129
 130         if (empty($emoticontexts[$lang][$theme])) { // No emoticons defined, nothing to process here
 131             return;
 132         }
 133
 134         // detect all the <script> zones to take out
 135         $excludes = array();
 136         preg_match_all('/<script language(.+?)<\/script>/is', $text, $listofexcludes);
 137
 138         // take out all the <script> zones from text
 139         foreach (array_unique($listofexcludes[0]) as $key => $value) {
 140             $excludes['<+'.$key.'+>'] = $value;
 141         }
 142         if ($excludes) {
 143             $text = str_replace($excludes, array_keys($excludes), $text);
 144         }
 145
 146         // this is the meat of the code - this is run every time
 147         $text = str_replace($emoticontexts[$lang][$theme], $emoticonimgs[$lang][$theme], $text);
 148
 149         // Recover all the <script> zones to text
 150         if ($excludes) {
 151             $text = str_replace(array_keys($excludes), $excludes, $text);
 152         }
 153     }
 154 }