<?php // This file is part of Moodle - http://moodle.org/ // // Moodle is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // Moodle is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with Moodle. If not, see <http://www.gnu.org/licenses/>. /** * Filter converting URLs in the text to HTML links * * @package filter * @subpackage urltolink * @copyright 2010 David Mudrak <david@moodle.com> * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ defined('MOODLE_INTERNAL') || die(); class filter_urltolink extends moodle_text_filter { /** * @var array global configuration for this filter * * This might be eventually moved into parent class if we found it * useful for other filters, too. */ protected static $globalconfig; /** * Apply the filter to the text * * @see filter_manager::apply_filter_chain() * @param string $text to be processed by the text * @param array $options filter options * @return string text after processing */ public function filter($text, array $options = array()) { if (!isset($options['originalformat'])) { // if the format is not specified, we are probably called by {@see format_string()} // in that case, it would be dangerous to replace URL with the link because it could // be stripped. therefore, we do nothing return $text; } if (in_array($options['originalformat'], explode(',', $this->get_global_config('formats')))) { $this->convert_urls_into_links($text); } return $text; } //////////////////////////////////////////////////////////////////////////// // internal implementation starts here //////////////////////////////////////////////////////////////////////////// /** * Returns the global filter setting * * If the $name is provided, returns single value. Otherwise returns all * global settings in object. Returns null if the named setting is not * found. * * @param mixed $name optional config variable name, defaults to null for all * @return string|object|null */ protected function get_global_config($name=null) { $this->load_global_config(); if (is_null($name)) { return self::$globalconfig; } elseif (array_key_exists($name, self::$globalconfig)) { return self::$globalconfig->{$name}; } else { return null; } } /** * Makes sure that the global config is loaded in $this->globalconfig * * @return void */ protected function load_global_config() { if (is_null(self::$globalconfig)) { self::$globalconfig = get_config('filter_urltolink'); } } /** * Given some text this function converts any URLs it finds into HTML links * * @param string $text Passed in by reference. The string to be searched for urls. */ protected function convert_urls_into_links(&$text) { //I've added img tags to this list of tags to ignore. //See MDL-21168 for more info. A better way to ignore tags whether or not //they are escaped partially or completely would be desirable. For example: //<a href="blah"> //&lt;a href="blah"&gt; //&lt;a href="blah"> $filterignoretagsopen = array('<a\s[^>]+?>'); $filterignoretagsclose = array('</a>'); filter_save_ignore_tags($text,$filterignoretagsopen,$filterignoretagsclose,$ignoretags); // Check if we support unicode modifiers in regular expressions. Cache it. // TODO: this check should be a environment requirement in Moodle 2.0, as far as unicode // chars are going to arrive to URLs officially really soon (2010?) // Original RFC regex from: http://www.bytemycode.com/snippets/snippet/796/ // Various ideas from: http://alanstorm.com/url_regex_explained // Unicode check, negative assertion and other bits from Moodle. static $unicoderegexp; if (!isset($unicoderegexp)) { $unicoderegexp = @preg_match('/\pL/u', 'a'); // This will fail silently, returning false, } // TODO MDL-21296 - use of unicode modifiers may cause a timeout $urlstart = '(?:http(s)?://|(?<!://)(www\.))'; $domainsegment = '(?:[\pLl0-9][\pLl0-9-]*[\pLl0-9]|[\pLl0-9])'; $numericip = '(?:(?:[0-9]{1,3}\.){3}[0-9]{1,3})'; $port = '(?::\d*)'; $pathchar = '(?:[\pL0-9\.!$&\'\(\)*+,;=_~:@-]|%[a-f0-9]{2})'; $path = "(?:/$pathchar*)*"; $querystring = '(?:\?(?:[\pL0-9\.!$&\'\(\)*+,;=_~:@/?-]|%[a-fA-F0-9]{2})*)'; $fragment = '(?:\#(?:[\pL0-9\.!$&\'\(\)*+,;=_~:@/?-]|%[a-fA-F0-9]{2})*)'; // Lookbehind assertions. // Is not HTML attribute or CSS URL property. Unfortunately legit text like "url(http://...)" will not be a link. $lookbehindstart = "(?<!=[\"']|\burl\([\"' ]|\burl\()"; $lookbehindend = "(?<![]),.;])"; $regex = "$lookbehindstart$urlstart((?:$domainsegment\.)+$domainsegment|$numericip)" . "($port?$path$querystring?$fragment?)$lookbehindend"; if ($unicoderegexp) { $regex = '#' . $regex . '#ui'; } else { $regex = '#' . preg_replace(array('\pLl', '\PL'), 'a-z', $regex) . '#i'; } $text = preg_replace($regex, '<a href="http$1://$2$3$4" class="_blanktarget">$0</a>', $text); if (!empty($ignoretags)) { $ignoretags = array_reverse($ignoretags); /// Reversed so "progressive" str_replace() will solve some nesting problems. $text = str_replace(array_keys($ignoretags),$ignoretags,$text); } if ($this->get_global_config('embedimages')) { // now try to inject the images, this code was originally in the mediapluing filter // this may be useful only if somebody relies on the fact the links in FORMAT_MOODLE get converted // to URLs which in turn change to real images $search = '/<a href="([^"]+\.(jpg|png|gif))" class="_blanktarget">([^>]*)<\/a>/is'; $text = preg_replace_callback($search, 'filter_urltolink_img_callback', $text); } } } /** * Change links to images into embedded images. * * This plugin is intended for automatic conversion of image URLs when FORMAT_MOODLE used. * * @param $link * @return string */ function filter_urltolink_img_callback($link) { if ($link[1] !== $link[3]) { // this is not a link created by this filter, because the url does not match the text return $link[0]; } return '<img class="filter_urltolink_image" alt="" src="'.$link[1].'" />'; }