filter.php

<?php
// This file is part of Moodle-botr-Filter
//
// Moodle-botr-Filter 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-botr-Filter 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-botr-Filter.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Filter for botr tags from actXcellence  botr.actxc.de
 * need help? ask help@actxc.de !
 * just paste the preview link into the text file.
 * it will recalculate the time for expiring and the signature key. 
 * example: 
 * http://botr.actxc.de/previews/f00b3lAw-YwSJg8N6?exp=1355928017&sig=5b40b2a48d1e29e5d4f2377c389a77a1
 * 
 * @package   filter_botr
 * @copyright 2012 Guido Hornig, actxcellence.de
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

 
defined('MOODLE_INTERNAL') || die();

require_once($CFG->libdir.'/filelib.php');

class filter_botr extends moodle_text_filter {

    function filter($text, array $options = array()) {

		// non string data can not be filtered anyway
        if (!is_string($text) or empty($text)) {
            return $text;
        }
		
        if (stripos($text, '[botr ' ) === false) {
            // performance shortcut - all regexes below contain botr.actxc tag,
            // if not present nothing can match
           return $text;
        }

        $newtext = $text; // we need to return the original value if regex fails!
		
        $search = '#(\[botr ([0-9a-z]{8})(?:[-_])?([0-9a-z]{8})?\])#is';
		
		// replace with video-player
        $newtext = preg_replace_callback($search, 'botr_create_js_embed', $newtext);

        if (empty($newtext) or $newtext === $text) {
            // error or not filtered
            unset($newtext);
           
		   // return original text
           return $text;
        }

        return $newtext;
    }
}

// Create the JS embed code for the BotR player
// $arguments is an array:
/*
    Array
    (
        [0] => [botr rdLv6JvZ-yIjjc1dh]
        [1] => [botr rdLv6JvZ-yIjjc1dh]
        [2] => rdLv6JvZ // video
        [3] => yIjjc1dh // optional player
    )
*/
function botr_create_js_embed($arguments) {
    global $CFG;

    $video_hash = $arguments[2];
    if (!empty($arguments[3])){
        $player_hash = $arguments[3];  // User player hash from user
    } else {
        $player_hash = $CFG->botr_defaultplayer; // no player specified, we take the default player
    }
    $content_mask = $CFG->botr_dnsmask; // allowed domains where embedding is allowed
    $timeout = $CFG->botr_timeout; // player timeout from config
    $path = "players/$video_hash-$player_hash.js";
    if($timeout < 1) {
        $url = "https://$content_mask/$path";  // no signed player wanted
    } else {
        $api_secret = $CFG->botr_secret;
        $expires = time() + 60 * $timeout;
        $signature = md5("$path:$expires:$api_secret");
        $url = "https://"."$content_mask/$path?exp=$expires&sig=$signature";
    }
	
	// final player
    return "<script type='text/javascript' src='$url'></script>";
}
?>