Question

Is is possible to intercept browser messages such as:

Firefox:

A script on this page may be busy, or
it may have stopped responding. You
can stop the script now, open the
script in the debugger, or let the
script continue.

I.E.

A script on this page is causing your
web browser to run slowly. If it
continues to run, your computer might
become unresponsive.

These messages are occuring due to the page having alot of javascript/jquery activity.

I appricate that the fact the these messages are appearing in the first place indicate a wider problem, but is there a way of intercerping this message/situation on the client side so that a more user friendly message can be shown?

Answer 1

No there’s no way to do this, imagine a malicious user writing a script which slows down your browser until is completely unusable, now the “Slow Script” Warning may come to the rescue, but what if he could intercept it and prevent it from being shown?

You’ll need to find a solution for the underlying problem, that is, in case that you’re doing a lot of calculations(which I suppose you do), you need to split those of into chunks, put them into a queue and process them either asynchronously(if possible) or in order, but with a small timeout in between.

In pseudo code it may look like this:

var queue = []; // put your functions or the data in here
function() processQueue{
    if (queue.length > 0) {
        var item = queue.shift() // pop of the first item of the queue
        item(); // call the function, or in case of data pass it to th processing function
        setTimeout(processQueue, 100); // wait 100 ms before processing the next chunck
    }
}

setTimeout(processQueue, 0);