Question

I’m trying to hook into a function that loads Facebook’s news feed:

UIIntentionalStream.instance && UIIntentionalStream.instance.loadOlderPosts();

on Facebook.com.

Is there a way for me to do this with my own JavaScript? Basically, I need to have some sort of callback – when that function is called, I’d like my own function to be called.

Answer 1

Try something like this:

var old = UIIntentionalStream.instance.loadOlderPosts;
UIIntentionalStream.instance.loadOlderPosts = function() {
    // hook before call
    old();
    // hook after call
};

Just hook in wherever you want, before or after the original function’s call.