Ive got some particularly nasty Javascript I am trying to debug. Specifically, I am trying to determine what functions are making certain http requests. Due to the shear size of the .js file and the generally poor quality, it is not as easy as hunting through the file manually.
I am vaguely experienced with Fiddler and Firebug, is this a capability built into those applications? Is there a better way to do this, if it is even possible?
Regardless of size or quality of the file, you should be able to grep for the keyword 'XMLHttpRequest' and set breakpoints where it's used.
You could also, on page load, before anything else is called, monkeypatch the XMLHttpRequest global:
var open = XMLHttpRequest.open;
XMLHttpRequest.open = function(){
console.log(this, arguments);
return open.apply(this, arguments);
};
Or something more sophisticated.
In the development version of Google Chrome you now have the ability to break the code on any XHR that is made. (wrench > tools > developer tools)
Yup! In firebug go to 'Net' on the top menu and choose 'XHR' from the menu right below to see all ajax calls being made during a visit to the page. This will display a wealth of information like the duration of the calls, and request / response headers.
