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<?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/>.
/**
* Base class for players which handle external links
*
* @package core_media
* @copyright 2016 Marina Glancy
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* Base class for players which handle external links (YouTube etc).
*
* As opposed to media files.
*
* @package core_media
* @copyright 2016 Marina Glancy
* @author 2011 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class core_media_player_external extends core_media_player {
/**
* Array of matches from regular expression - subclass can assume these
* will be valid when the embed function is called, to save it rerunning
* the regex.
* @var array
*/
protected $matches;
/**
* Part of a regular expression, including ending ~ symbol (note: these
* regexes use ~ instead of / because URLs and HTML code typically include
* / symbol and makes harder to read if you have to escape it).
* Matches the end part of a link after you have read the 'important' data
* including optional #d=400x300 at end of url, plus content of <a> tag,
* up to </a>.
* @var string
*/
const END_LINK_REGEX_PART = '[^#]*(#d=([\d]{1,4})x([\d]{1,4}))?~si';
public function embed($urls, $name, $width, $height, $options) {
return $this->embed_external(reset($urls), $name, $width, $height, $options);
}
/**
* Obtains HTML code to embed the link.
* @param moodle_url $url Single URL to embed
* @param string $name Display name; '' to use default
* @param int $width Optional width; 0 to use default
* @param int $height Optional height; 0 to use default
* @param array $options Options array
* @return string HTML code for embed
*/
protected abstract function embed_external(moodle_url $url, $name, $width, $height, $options);
public function list_supported_urls(array $urls, array $options = array()) {
// These only work with a SINGLE url (there is no fallback).
if (count($urls) != 1) {
return array();
}
$url = reset($urls);
// Check against regex.
if (preg_match($this->get_regex(), $url->out(false), $this->matches)) {
return array($url);
}
return array();
}
/**
* Returns regular expression used to match URLs that this player handles
* @return string PHP regular expression e.g. '~^https?://example.org/~'
*/
protected function get_regex() {
return '~^unsupported~';
}
/**
* Annoyingly, preg_match $matches result does not always have the same
* number of parameters - it leaves out optional ones at the end. WHAT.
* Anyway, this function can be used to fix it.
* @param array $matches Array that should be adjusted
* @param int $count Number of capturing groups (=6 to make $matches[6] work)
*/
protected static function fix_match_count(&$matches, $count) {
for ($i = count($matches); $i <= $count; $i++) {
$matches[$i] = false;
}
}
}