Question

How do we make a web page to execute a JavaScript function immediately after Google Analytics creates/updates all its cookies and the page DOM is loaded.

Can it be done with jQuery? How?

This function gets information from the GA cookies. I’ve tried executing the function when the page DOM is loaded, but sometimes GA has not created it’s cookies yet.

Answer 1

There are 2 elements here: First, DOM ready with jQuery. That’s easy:

$(document).ready(function(){
//do something
});

The way to ensure that your function executes after Google Analytics has created its cookies (once it had implicitly executed initData()) is to pass the function within the _gaq array queue so that it gets executed after the _trackPageview call.

For example:

_gaq.push(["_trackPageview"]);
_gaq.push(function(){
    //when this executes, the google analytics cookies definitely exist
});

So, you could put the following anywhere on the page below _gaq.push(["_trackPageview"]) (or after any _gaq call that initiates the cookies; most commonly, _trackPageview, _trackEvent, and _setCustomVar.

_gaq.push(function(){
    //do something
});

Now to ensure that the function both executes after DOM Ready and that initData() is implicitly called, you can either do this:

_gaq.push(function(){
    $(document).ready(function(){
        //do something
    });
});

Or:

$(document).ready(function(){
    _gaq.push(function(){
        //do something
   });
});

They both do what you’re looking for, though it sounds like the first one better fits your mental model of what you’re trying to accomplish.