Javascript this object inside intervals/timeouts

Question

I have a method that is a big setInterval statement, and it needs access to the this object of the object that owns the method from inside the interval. I implemented a simple closure, but it doesn't seem very elegant:

connect: function(to, rate, callback){
    var cthis = this,                             //set cthis to this,
    connectIntervalID = setInterval(function(){
        if(cthis.attemptConnect(to)){             //reference it here,
            clearInterval(connectIntervalID)
            cthis.startListening(10)              //here,
            callback && callback.apply(cthis, []) //and here
        }
    }, rate)
}

You could also do it with apply or call, if you wanted to use this instead of cthis

connect: function(to, rate, callback){
    var cthis = this,
    tempFunc = function(){
        if(this.attemptConnect(to)){                 
            clearInterval(connectIntervalID)
            this.startListening(10)              
            callback && callback.apply(this, []) 
         }
     }�       
     connectIntervalID = setInterval(function(){tempFunc.apply(cthis, [])}, rate)
 }

However, that seems even worse...

Answer 1

Using a .bind makes it a bit better (in my opinion, you may or may not agree):

support code:

function $A(args){
   var out = [];
   for(var i=0, l=args.length; i<l; i++){ out.push(args[i]); }
   return out;
}

Function.prototype.bind = function() {
   var __method = this, args = $A(arguments), object = args.shift();

   return function() {
      return __method.apply(object || this, args.concat( $A(arguments) ));
   };
};

and your code becomes:

connect: function(to, rate, callback){
    connectIntervalID = setInterval((function(){
        if(this.attemptConnect(to)){             //reference it here,
            clearInterval(connectIntervalID)
            this.startListening(10)              //here,
            callback && callback.apply(this, []) //and here
        }
    }).bind(this), rate)
}

But I'm afraid you won't get a whole lot better.