Multiple Timers with setTimeInterval
- by visibleinvisibly
I am facing a problem with setInterval being used in a loop.
I have a function subscribeFeed( ) which takes an array of urls as input.
It loops through the url array and subscribes each url to getFeedAutomatically() using a setInterval function.
so if three URL's are there in the array, then 3 setInterval's will be called.
The problem is
1)how to distinguish which setInterval is called for which URL.
2)it is causing Runtime exception in setInterval( i guess because of closure problem in javascript)
//constructor
function myfeed(){
this.feedArray = [];
}
myfeed.prototype.constructor= myfeed;
myfeed.prototype.subscribeFeed =function(feedUrl){
var i=0;
var url;
var count = 0;
var _this = this;
var feedInfo = {
url : [],
status : ""
};
var urlinfo = [];
feedUrl = (feedUrl instanceof Array) ? feedUrl : [feedUrl];
//notifyInterval = (notifyInterval instanceof Array) ? notifyInterval: [notifyInterval];
for (i = 0; i < feedUrl.length; i++) {
urlinfo[i] = {
url:'',
notifyInterval:5000,// Default Notify/Refresh interval for the feed
isenable:true, // true allows the feed to be fetched from the URL
timerID: null, //default ID is null
called : false,
position : 0,
getFeedAutomatically : function(url){
_this.getFeedUpdate(url);
},
};
urlinfo[i].url = feedUrl[i].URL;
//overide the default notify interval
if(feedUrl[i].NotifyInterval /*&& (feedUrl[i] !=undefined)*/){
urlinfo[i].notifyInterval = feedUrl[i].NotifyInterval;
}
// Trigger the Feed registered event with the info about URL and status
feedInfo.url[i] = feedUrl[i].URL;
//Set the interval to get the feed.
urlinfo[i].timerID = setInterval(function(){
urlinfo[i].getFeedAutomatically(urlinfo[i].url);
}, urlinfo[i].notifyInterval);
this.feedArray.push(urlinfo[i]);
}
}
// The getFeedUpate function will make an Ajax request and coninue
myfeed.prototype.getFeedUpdate = function( ){
}
I am posting the same on jsfiddle
http://jsfiddle.net/visibleinvisibly/S37Rj/
Thanking you in advance
