Question

Given this var:

somevar = {dothis: function(){console('yay')}};

If I want to hijack it, I would think i’d do something like:

tempvar = somevar;
somevar = function(){ console.log('yoink'); tempvar();};

But if I know that the var is going to be redefined in 60 seconds, and I want to hijack it in 65 seconds, how do I do that? Wouldn’t a setTimeout parse the function immediately, and then refer to the old hijacked function?

Thanks in advance.

Answer 1

Try something like this:

// initial data
var somevar = {
  dothis: function(){
    console.log('yay');
  }
};

somevar.dothis(); // output: yay

// hijacking in 1 second
setTimeout(function () {
    console.log('hijacking');
    somevar.dothis = (function (orig) {
        return function () {
            console.log('yoink');
            orig.apply(this, arguments);
        };
    }(somevar.dothis));
}, 1000);

// saved reference running 1.5 seconds later (0.5 seconds after hijacking)
setTimeout(somevar.dothis, 1500); // output (still): yay

// live reference running 2 seconds later (1 second after hijacking)
setTimeout(function () {
  somevar.dothis(); // output: yoink / yay
}, 2000);

demo: http://jsfiddle.net/MDLZt/