provide small wrapper around server side events and provide a fallback for IE

1 files changed, 73 insertions, 0 deletions

diff --git a/lib/eventsource.php b/lib/eventsource.php
new file mode 100644
index 00000000000..c123eb4b837
--- /dev/null
+++ b/lib/eventsource.php
@@ -0,0 +1,73 @@
+<?php
+
+/**
+* ownCloud
+*
+* @author Robin Appelman
+* @copyright 2012 Robin Appelman icewind1991@gmail.com
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+* License as published by the Free Software Foundation; either
+* version 3 of the License, or any later version.
+*
+* This library 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 AFFERO GENERAL PUBLIC LICENSE for more details.
+*
+* You should have received a copy of the GNU Affero General Public
+* License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+*
+*/
+
+/**
+ * wrapper for server side events (http://en.wikipedia.org/wiki/Server-sent_events)
+ * includes a fallback for older browsers and IE
+ *
+ * use server side events with causion, to many open requests can hang the server
+ */
+class OC_EventSource{
+	private $fallback;
+	private $fallBackId=0;
+	
+	public function __construct(){
+		ob_end_clean();
+		header('Cache-Control: no-cache');
+		$this->fallback=isset($_GET['fallback']) and $_GET['fallback']=='true';
+		if($this->fallback){
+			$fallBackId=$_GET['fallback_id'];
+			header("Content-Type: text/html");
+			echo str_repeat('<span></span>'.PHP_EOL,10); //dummy data to keep IE happy
+		}else{
+			header("Content-Type: text/event-stream");
+		}
+		flush();
+
+	}
+
+	/**
+	 * send a message to the client
+	 * @param string type
+	 * @param object data
+	 *
+	 * if only one paramater is given, a typeless message will be send with that paramater as data
+	 */
+	public function send($type,$data=null){
+		if(is_null($data)){
+			$data=$type;
+			$type=null;
+		}
+		if($this->fallback){
+			$response='<script type="text/javascript">window.parent.OC.EventSource.fallBackCallBack('.$this->fallBackId.',"'.$type.'","'.json_encode($data).'")</script>'.PHP_EOL;
+			echo $response;
+		}else{
+			if($type){
+				echo 'event: '.$type.PHP_EOL;
+			}
+			echo 'data: '.json_encode($data).PHP_EOL;
+		}
+		echo PHP_EOL;
+		flush();
+	}
+}
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