Question

Is it possible to set the ‘this’ or caller of a function yet set that as a callback?

this.CallServer({ url: 'myurl', success: F.call(myDOMElement) });

F function(data){ $(this).text(data); }

I realize that I can wrap the callback function and pass the DOMElement as a param calling F like below but I was wondering if there is a way to do it closer to above.

this.CallServer({url: 'myurl', success: function(data){F(data, myDOMElement);}});
F function(data, elem){ $(elem).text(data); }

Answer 1

this.CallServer({ url: 'myurl', success: F.bind(myDOMElement) });

bind will return the same function, except that it has a fixed value of this whenever called.

Docs, including shim for older browsers.

Simply speaking, bind could be defined as:

func.bind = function(thisValue) {
    return function() {
        return func.apply(thisValue);
    };
};

E.g.

var func = function() { return this };
var bound = func.bind([1, 2, 3]);
var result = bound(); // [1, 2, 3]