Halt JavaScript execution without locking up the browser

javascript execution
cllpse picture cllpse · Jan 19, 2010 · Viewed 13.3k times · Source

Are you able to halt JavaScript execution without locking up the browser? The way you would normally halt execution is to do an infinite while()-loop, but in the case of FireFox, it locks up the browser until the loop has ended.

What's your take on this?


I am trying to override window.confirm() to implement my own dialog using HTML. I am doing this so I don't have to change existing code (it's a pretty big code-base).

I need to be able to halt execution to allow user-input; to in turn return a boolean like the standard confirm function does:

if (confirm("..."))
{
    // user pressed "OK"
}
else
{
    // user pressed "Cancel"
}



Update

To my knowledge; this cannot be done using setTimeout() or setInterval() since these functions execute the code thats given to them asynchronously.

Answer

Ben Zotto picture Ben Zotto · Jan 19, 2010

confirm() prompt() and alert() are special functions--they call out of the JavaScript sandbox into the browser, and the browser suspends JavaScript execution. You can't do the same thing, since you need to build your functionality into JavaScript.

I don't think there's a great way to drop in a replacement without doing some restructuring along the lines of:

myconfirmfunction(function() {
   /* OK callback */
}, function() {
   /* cancel callback */
});

Related questions

How to force Sequential Javascript Execution?

I've only found rather complicated answers involving classes, event handlers and callbacks (which seem to me to be a somewhat sledgehammer approach). I think callbacks may be useful but I cant seem to apply these in the simplest context. See …

Read More
How does Asynchronous Javascript Execution happen? and when not to use return statement?

// synchronous Javascript var result = db.get('select * from table1'); console.log('I am syncronous'); // asynchronous Javascript db.get('select * from table1', function(result){ // do something with the result }); console.log('I am asynchronous') I know in synchronous code, …

Read More
Prevent JavaScript function from running twice (setTimeout)

I have this function that runs for several seconds with the use of setTimeout. This function is ran when a button is clicked. function complete() { var div = document.getElementById('log'); setTimeout(function(){ div.innerHTML = div.innerHTML + intro[Math.floor(Math.…

Read More