debug JS code which triggers an alert()

Question

I have a system which is built using the ext-js library. Part of the system lists orders that are flowing through an online store. When a row is clicked, additional order detail

Answer 1

Firebug has a command line API to programmatically create breakpoints. For example:

debug(fn);

creates a breakpoint to the function fn. Unfortunately this can't be used for functions with native code (built-in functions like alert). However, you can use this trick.

Insert a script block in your code with this script-

window.alert_ = window.alert;
window.alert = function() {
    alert_.apply(window,arguments)
};

What you've done is to redefine window.alert with your own which does the same thing.

Now attach the breakpoint in firebug with:

debug(alert);

Now the next time a script calls alert, you will get a breakpoint in your function. You can then analyze the stack trace and find out where it is getting called from.