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

1 files changed, 94 insertions, 0 deletions

diff --git a/core/js/eventsource.js b/core/js/eventsource.js
new file mode 100644
index 00000000000..422f97657bd
--- /dev/null
+++ b/core/js/eventsource.js
@@ -0,0 +1,94 @@
+/**
+ * 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
+ */
+
+OC.EventSource=function(src){
+	if(!this.useFallBack && typeof EventSource !='undefined'){
+		this.source=new EventSource(src);
+		this.source.onmessage=function(e){
+			for(var i=0;i<this.typelessListeners.length;i++){
+				this.typelessListeners[i](JSON.parse(e.data));
+			}
+		}
+	}else{
+		iframeId='oc_eventsource_iframe_'+OC.EventSource.iframeCount;
+		OC.EventSource.fallBackSources[OC.EventSource.iframeCount]=this;
+		this.iframe=$('<iframe/>');
+		this.iframe.attr('id',iframeId);
+		this.iframe.hide();
+		this.iframe.attr('src',src+'?fallback=true&fallback_id='+OC.EventSource.iframeCount);
+		$('body').append(this.iframe);
+		this.useFallBack=true;
+		OC.EventSource.iframeCount++
+
+	}
+}
+OC.EventSource.fallBackSources=[];
+OC.EventSource.iframeCount=0;//number of fallback iframes
+OC.EventSource.fallBackCallBack=function(id,type,data){
+	OC.EventSource.fallBackSources[id].fallBackCallBack(type,JSON.parse(data));
+}
+OC.EventSource.prototype={
+	typelessListeners:[],
+	iframe:null,
+	listeners:{},//only for fallback
+	useFallBack:false,
+	fallBackCallBack:function(type,data){
+		if(type){
+			for(var i=0;i<this.listeners[type].length;i++){
+				this.listeners[type][i](data);
+			}
+		}else{
+			for(var i=0;i<this.typelessListeners.length;i++){
+				this.typelessListeners[i](data);
+			}
+		}
+	},
+	lastLength:0,//for fallback
+	listen:function(type,callback){
+		if(callback && callback.call){
+			
+			if(type){
+				if(this.useFallBack){
+					if(!this.listeners[type]){
+						this.listeners[type]=[];
+					}
+					this.listeners[type].push(callback);
+				}else{
+					this.source.addEventListener(type,function(e){
+						callback(JSON.parse(e.data));
+					},false);
+				}
+			}else{
+				typelessListeners.push(callback);
+			}
+		}
+	},
+	close:function(){
+		this.source.close();
+	}
+}