Proyectos de Subversion Moodle

<?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/>.

/**

 * This plugin is used to access files by providing an url

 *

 * @since Moodle 2.0

 * @package    repository_url

 * @copyright  2010 Dongsheng Cai {@link http://dongsheng.org}

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

require_once($CFG->dirroot . '/repository/lib.php');

require_once(__DIR__.'/locallib.php');

/**

 * repository_url class

 * A subclass of repository, which is used to download a file from a specific url

 *

 * @since Moodle 2.0

 * @package    repository_url

 * @copyright  2009 Dongsheng Cai {@link http://dongsheng.org}

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class repository_url extends repository {

    /** @var int Maximum time of recursion. */

    const MAX_RECURSION_TIME = 5;

    /** @var int Maximum number of CSS imports. */

    protected const MAX_CSS_IMPORTS = 10;

    /** @var int CSS import counter. */

    protected int $cssimportcounter = 0;

    var $processedfiles = array();

    /** @var int Recursion counter. */

    var $recursioncounter = 0;

    /** @var string file URL. */

    public $file_url;

    /**

     * @param int $repositoryid

     * @param object $context

     * @param array $options

     */

    public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array()){

        global $CFG;

        parent::__construct($repositoryid, $context, $options);

        $this->file_url = optional_param('file', '', PARAM_RAW);

        $this->file_url = $this->escape_url($this->file_url);

    }

    public function check_login() {

        if (!empty($this->file_url)) {

            return true;

        } else {

            return false;

        }

    }

    /**

     * @return mixed

     */

    public function print_login() {

        $strdownload = get_string('download', 'repository');

        $strname     = get_string('rename', 'repository_url');

        $strurl      = get_string('url', 'repository_url');

        if ($this->options['ajax']) {

            $url = new stdClass();

            $url->label = $strurl.': ';

            $url->id   = 'fileurl';

            $url->type = 'text';

            $url->name = 'file';

            $ret['login'] = array($url);

            $ret['login_btn_label'] = get_string('download', 'repository_url');

            $ret['allowcaching'] = true; // indicates that login form can be cached in filepicker.js

            return $ret;

        } else {

            echo <<<EOD

<table>

<tr>

<td>{$strurl}: </td><td><input name="file" type="text" /></td>

</tr>

</table>

<input type="submit" value="{$strdownload}" />

EOD;

        }

    }

    /**

     * @param mixed $path

     * @param string $search

     * @return array

     */

    public function get_listing($path='', $page='') {

        $ret = array();

        $ret['list'] = array();

        $ret['nosearch'] = true;

        $ret['norefresh'] = true;

        $ret['nologin'] = true;

        $this->file_url = clean_param($this->file_url, PARAM_URL);

        if (empty($this->file_url)) {

            throw new repository_exception('validfiletype', 'repository_url');

        }

        $this->parse_file(null, $this->file_url, $ret, true);

        return $ret;

    }

    /**

     * Parses one file (either html or css)

     *

     * @param string $baseurl (optional) URL of the file where link to this file was found

     * @param string $relativeurl relative or absolute link to the file

     * @param array $list

     * @param bool $mainfile true only for main HTML false and false for all embedded/linked files

     */

    protected function parse_file($baseurl, $relativeurl, &$list, $mainfile = false) {

        if (preg_match('/([\'"])(.*)\1/', $relativeurl, $matches)) {

            $relativeurl = $matches[2];

        }

        if (empty($baseurl)) {

            $url = $relativeurl;

        } else {

            $url = htmlspecialchars_decode(url_to_absolute($baseurl, $relativeurl), ENT_COMPAT);

        }

        if (in_array($url, $this->processedfiles)) {

            // Avoid endless recursion for the same URL with same parameters.

            return;

        }

        // Remove the query string and anchors before check.

        $recursioncheckurl = (new moodle_url($url))->out_omit_querystring();

        if (in_array($recursioncheckurl, $this->processedfiles)) {

            $this->recursioncounter++;

        }

        if ($this->recursioncounter >= self::MAX_RECURSION_TIME) {

            // Avoid endless recursion for the same URL with different parameters.

            return;

        }

        $this->processedfiles[] = $url;

        $curl = new curl([

            'proxy' => true,

        ]);

        $curl->setopt([

            'CURLOPT_FOLLOWLOCATION' => true,

            'CURLOPT_MAXREDIRS' => 3,

        ]);

        $msg = $curl->head($url);

        $info = $curl->get_info();

        if ($info['http_code'] != 200) {

            if ($mainfile) {

                $list['error'] = $msg;

            }

        } else {

            $csstoanalyze = '';

            if ($mainfile && (strstr($info['content_type'], 'text/html') || empty($info['content_type']))) {

                // parse as html

                $htmlcontent = $curl->get($info['url']);

                $ddoc = new DOMDocument();

                @$ddoc->loadHTML($htmlcontent);

                // extract <img>

                $tags = $ddoc->getElementsByTagName('img');

                foreach ($tags as $tag) {

                    $url = $tag->getAttribute('src');

                    $this->add_image_to_list($info['url'], $url, $list);

                }

                // analyse embedded css (<style>)

                $tags = $ddoc->getElementsByTagName('style');

                foreach ($tags as $tag) {

                    if ($tag->getAttribute('type') == 'text/css') {

                        $csstoanalyze .= $tag->textContent."\n";

                    }

                }

                // analyse links to css (<link type='text/css' href='...'>)

                $tags = $ddoc->getElementsByTagName('link');

                foreach ($tags as $tag) {

                    if ($tag->getAttribute('type') == 'text/css' && strlen($tag->getAttribute('href'))) {

                        $this->parse_file($info['url'], $tag->getAttribute('href'), $list);

                    }

                }

            } else if (strstr($info['content_type'], 'css')) {

                // parse as css

                $csscontent = $curl->get($info['url']);

                $csstoanalyze .= $csscontent."\n";

            } else if (strstr($info['content_type'], 'image/')) {

                // download this file

                $this->add_image_to_list($info['url'], $info['url'], $list);

            } else {

                $list['error'] = get_string('validfiletype', 'repository_url');

            }

            // parse all found css styles

            if (strlen($csstoanalyze)) {

                $urls = extract_css_urls($csstoanalyze);

                if (!empty($urls['property'])) {

                    foreach ($urls['property'] as $url) {

                        $this->add_image_to_list($info['url'], $url, $list);

                    }

                }

                if (!empty($urls['import'])) {

                    foreach ($urls['import'] as $cssurl) {

                        // Limit the number of CSS imports to avoid infinite imports.

                        if ($this->cssimportcounter >= self::MAX_CSS_IMPORTS) {

                            return;

                        }

                        $this->cssimportcounter++;

                        $this->parse_file($info['url'], $cssurl, $list);

                    }

                }

            }

        }

    }

    protected function add_image_to_list($baseurl, $url, &$list) {

        if (empty($list['list'])) {

            $list['list'] = array();

        }

        $src = url_to_absolute($baseurl, htmlspecialchars_decode($url, ENT_COMPAT));

        foreach ($list['list'] as $image) {

            if ($image['source'] == $src) {

                return;

            }

        }

        $list['list'][] = array(

            'title'=>$this->guess_filename($url, ''),

            'source'=>$src,

            'thumbnail'=>$src,

            'thumbnail_height'=>84,

            'thumbnail_width'=>84

        );

    }

    public function guess_filename($url, $type) {

        $pattern = '#\/([\w_\?\-.]+)$#';

        $matches = null;

        preg_match($pattern, $url, $matches);

        if (empty($matches[1])) {

            return $url;

        } else {

            return $matches[1];

        }

    }

    /**

     * Escapes a url by replacing spaces with %20.

     *

     * Note: In general moodle does not automatically escape urls, but for the purposes of making this plugin more user friendly

     * and make it consistent with some other areas in moodle (such as mod_url), urls will automatically be escaped.

     *

     * If moodle_url or PARAM_URL is changed to clean characters that need to be escaped, then this function can be removed

     *

     * @param string $url An unescaped url.

     * @return string The escaped url

     */

    protected function escape_url($url) {

        $url = str_replace('"', '%22', $url);

        $url = str_replace('\'', '%27', $url);

        $url = str_replace(' ', '%20', $url);

        $url = str_replace('<', '%3C', $url);

        $url = str_replace('>', '%3E', $url);

        return $url;

    }

    public function supported_returntypes() {

        return (FILE_INTERNAL | FILE_EXTERNAL);

    }

    /**

     * Return the source information

     *

     * @param stdClass $url

     * @return string|null

     */

    public function get_file_source_info($url) {

        return $url;

    }

    /**

     * file types supported by url downloader plugin

     *

     * @return array

     */

    public function supported_filetypes() {

        return array('web_image');

    }

    /**

     * Is this repository accessing private data?

     *

     * @return bool

     */

    public function contains_private_data() {

        return false;

    }

}