Detecting alerts with a Chrome extension

Question

Is there some way for a Chrome extension to detect an alert box which shows up immediately after an external website's page-load? I understand that once an alert box shows up, JavaScript execution is suspended.

A certain website throws a specific alert and I need to be able to listen for that. Ideally, I want to extract the text within the alert.

Answer 1

You can overwrite the native alert() function

var native_alert = alert;

alert = function(msg) {
    console.log('call to alert() - message: '+msg);
    native_alert(msg);    
}

alert('intercepted!');

DEMO : http://jsfiddle.net/jHTeK/2/