repository/url/lib.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  * This plugin is used to access files by providing an url
  20  *
  21  * @since Moodle 2.0
  22  * @package    repository_url
  23  * @copyright  2010 Dongsheng Cai {@link http://dongsheng.org}
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26 require_once($CFG->dirroot . '/repository/lib.php');
  27 require_once(__DIR__.'/locallib.php');
  28
  29 /**
  30  * repository_url class
  31  * A subclass of repository, which is used to download a file from a specific url
  32  *
  33  * @since Moodle 2.0
  34  * @package    repository_url
  35  * @copyright  2009 Dongsheng Cai {@link http://dongsheng.org}
  36  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  37  */
  38 class repository_url extends repository {
  39     /** @var int Maximum time of recursion. */
  40     const MAX_RECURSION_TIME = 5;
  41     var $processedfiles = array();
  42     /** @var int Recursion counter. */
  43     var $recursioncounter = 0;
  44
  45     /**
  46      * @param int $repositoryid
  47      * @param object $context
  48      * @param array $options
  49      */
  50     public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array()){
  51         global $CFG;
  52         parent::__construct($repositoryid, $context, $options);
  53         $this->file_url = optional_param('file', '', PARAM_RAW);
  54         $this->file_url = $this->escape_url($this->file_url);
  55     }
  56
  57     public function check_login() {
  58         if (!empty($this->file_url)) {
  59             return true;
  60         } else {
  61             return false;
  62         }
  63     }
  64     /**
  65      * @return mixed
  66      */
  67     public function print_login() {
  68         $strdownload = get_string('download', 'repository');
  69         $strname     = get_string('rename', 'repository_url');
  70         $strurl      = get_string('url', 'repository_url');
  71         if ($this->options['ajax']) {
  72             $url = new stdClass();
  73             $url->label = $strurl.': ';
  74             $url->id   = 'fileurl';
  75             $url->type = 'text';
  76             $url->name = 'file';
  77
  78             $ret['login'] = array($url);
  79             $ret['login_btn_label'] = get_string('download', 'repository_url');
  80             $ret['allowcaching'] = true; // indicates that login form can be cached in filepicker.js
  81             return $ret;
  82         } else {
  83             echo <<<EOD
  84 <table>
  85 <tr>
  86 <td>{$strurl}: </td><td><input name="file" type="text" /></td>
  87 </tr>
  88 </table>
  89 <input type="submit" value="{$strdownload}" />
  90 EOD;
  91
  92         }
  93     }
  94
  95     /**
  96      * @param mixed $path
  97      * @param string $search
  98      * @return array
  99      */
 100     public function get_listing($path='', $page='') {
 101         $ret = array();
 102         $ret['list'] = array();
 103         $ret['nosearch'] = true;
 104         $ret['norefresh'] = true;
 105         $ret['nologin'] = true;
 106
 107         $this->file_url = clean_param($this->file_url, PARAM_URL);
 108         if (empty($this->file_url)) {
 109             throw new repository_exception('validfiletype', 'repository_url');
 110         }
 111
 112         $this->parse_file(null, $this->file_url, $ret, true);
 113         return $ret;
 114     }
 115
 116     /**
 117      * Parses one file (either html or css)
 118      *
 119      * @param string $baseurl (optional) URL of the file where link to this file was found
 120      * @param string $relativeurl relative or absolute link to the file
 121      * @param array $list
 122      * @param bool $mainfile true only for main HTML false and false for all embedded/linked files
 123      */
 124     protected function parse_file($baseurl, $relativeurl, &$list, $mainfile = false) {
 125         if (preg_match('/([\'"])(.*)\1/', $relativeurl, $matches)) {
 126             $relativeurl = $matches[2];
 127         }
 128         if (empty($baseurl)) {
 129             $url = $relativeurl;
 130         } else {
 131             $url = htmlspecialchars_decode(url_to_absolute($baseurl, $relativeurl));
 132         }
 133         if (in_array($url, $this->processedfiles)) {
 134             // Avoid endless recursion for the same URL with same parameters.
 135             return;
 136         }
 137         // Remove the query string before check.
 138         $recursioncheckurl = preg_replace('/\?.*/', '', $url);
 139         if (in_array($recursioncheckurl, $this->processedfiles)) {
 140             $this->recursioncounter++;
 141         }
 142         if ($this->recursioncounter >= self::MAX_RECURSION_TIME) {
 143             // Avoid endless recursion for the same URL with different parameters.
 144             return;
 145         }
 146         $this->processedfiles[] = $url;
 147         $curl = new curl;
 148         $curl->setopt(array('CURLOPT_FOLLOWLOCATION' => true, 'CURLOPT_MAXREDIRS' => 3));
 149         $msg = $curl->head($url);
 150         $info = $curl->get_info();
 151         if ($info['http_code'] != 200) {
 152             if ($mainfile) {
 153                 $list['error'] = $msg;
 154             }
 155         } else {
 156             $csstoanalyze = '';
 157             if ($mainfile && (strstr($info['content_type'], 'text/html') || empty($info['content_type']))) {
 158                 // parse as html
 159                 $htmlcontent = $curl->get($info['url']);
 160                 $ddoc = new DOMDocument();
 161                 @$ddoc->loadHTML($htmlcontent);
 162                 // extract <img>
 163                 $tags = $ddoc->getElementsByTagName('img');
 164                 foreach ($tags as $tag) {
 165                     $url = $tag->getAttribute('src');
 166                     $this->add_image_to_list($info['url'], $url, $list);
 167                 }
 168                 // analyse embedded css (<style>)
 169                 $tags = $ddoc->getElementsByTagName('style');
 170                 foreach ($tags as $tag) {
 171                     if ($tag->getAttribute('type') == 'text/css') {
 172                         $csstoanalyze .= $tag->textContent."\n";
 173                     }
 174                 }
 175                 // analyse links to css (<link type='text/css' href='...'>)
 176                 $tags = $ddoc->getElementsByTagName('link');
 177                 foreach ($tags as $tag) {
 178                     if ($tag->getAttribute('type') == 'text/css' && strlen($tag->getAttribute('href'))) {
 179                         $this->parse_file($info['url'], $tag->getAttribute('href'), $list);
 180                     }
 181                 }
 182             } else if (strstr($info['content_type'], 'css')) {
 183                 // parse as css
 184                 $csscontent = $curl->get($info['url']);
 185                 $csstoanalyze .= $csscontent."\n";
 186             } else if (strstr($info['content_type'], 'image/')) {
 187                 // download this file
 188                 $this->add_image_to_list($info['url'], $info['url'], $list);
 189             } else {
 190                 $list['error'] = get_string('validfiletype', 'repository_url');
 191             }
 192
 193             // parse all found css styles
 194             if (strlen($csstoanalyze)) {
 195                 $urls = extract_css_urls($csstoanalyze);
 196                 if (!empty($urls['property'])) {
 197                     foreach ($urls['property'] as $url) {
 198                         $this->add_image_to_list($info['url'], $url, $list);
 199                     }
 200                 }
 201                 if (!empty($urls['import'])) {
 202                     foreach ($urls['import'] as $cssurl) {
 203                         $this->parse_file($info['url'], $cssurl, $list);
 204                     }
 205                 }
 206             }
 207         }
 208     }
 209     protected function add_image_to_list($baseurl, $url, &$list) {
 210         if (empty($list['list'])) {
 211             $list['list'] = array();
 212         }
 213         $src = url_to_absolute($baseurl, htmlspecialchars_decode($url));
 214         foreach ($list['list'] as $image) {
 215             if ($image['source'] == $src) {
 216                 return;
 217             }
 218         }
 219         $list['list'][] = array(
 220             'title'=>$this->guess_filename($url, ''),
 221             'source'=>$src,
 222             'thumbnail'=>$src,
 223             'thumbnail_height'=>84,
 224             'thumbnail_width'=>84
 225         );
 226     }
 227     public function guess_filename($url, $type) {
 228         $pattern = '#\/([\w_\?\-.]+)$#';
 229         $matches = null;
 230         preg_match($pattern, $url, $matches);
 231         if (empty($matches[1])) {
 232             return $url;
 233         } else {
 234             return $matches[1];
 235         }
 236     }
 237
 238     /**
 239      * Escapes a url by replacing spaces with %20.
 240      *
 241      * Note: In general moodle does not automatically escape urls, but for the purposes of making this plugin more user friendly
 242      * and make it consistent with some other areas in moodle (such as mod_url), urls will automatically be escaped.
 243      *
 244      * If moodle_url or PARAM_URL is changed to clean characters that need to be escaped, then this function can be removed
 245      *
 246      * @param string $url An unescaped url.
 247      * @return string The escaped url
 248      */
 249     protected function escape_url($url) {
 250         $url = str_replace('"', '%22', $url);
 251         $url = str_replace('\'', '%27', $url);
 252         $url = str_replace(' ', '%20', $url);
 253         $url = str_replace('<', '%3C', $url);
 254         $url = str_replace('>', '%3E', $url);
 255         return $url;
 256     }
 257
 258     public function supported_returntypes() {
 259         return (FILE_INTERNAL | FILE_EXTERNAL);
 260     }
 261
 262     /**
 263      * Return the source information
 264      *
 265      * @param stdClass $url
 266      * @return string|null
 267      */
 268     public function get_file_source_info($url) {
 269         return $url;
 270     }
 271
 272     /**
 273      * file types supported by url downloader plugin
 274      *
 275      * @return array
 276      */
 277     public function supported_filetypes() {
 278         return array('web_image');
 279     }
 280
 281     /**
 282      * Is this repository accessing private data?
 283      *
 284      * @return bool
 285      */
 286     public function contains_private_data() {
 287         return false;
 288     }
 289 }