nextcloud/core/js/eventsource.js

109 lines
3.0 KiB
JavaScript

/**
* 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
*/
/**
* create a new event source
* @param string src
* @param object data to be send as GET
*/
OC.EventSource=function(src,data){
var dataStr='';
for(name in data){
dataStr+=name+'='+encodeURIComponent(data[name])+'&';
}
if(!this.useFallBack && typeof EventSource !='undefined'){
this.source=new EventSource(src+'?'+dataStr);
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+'&'+dataStr);
$('body').append(this.iframe);
this.useFallBack=true;
OC.EventSource.iframeCount++
}
//add close listener
this.listen('__internal__',function(data){
if(data=='close'){
this.close();
}
}.bind(this));
}
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();
}
}