> It overrides alert() but doesn't - and can't - duplicate its blocking behavior.
If you really wanted to, I think you could set up an endpoint on your server to be long polled with synchronous XHR in a while loop, while you set up the popup in an iframe. When the popup is clicked, you send a notification to the server so the next synchronous request returns 200 and you dispose of the iframe.
I'm surprised that the SO poster got the synchronous XHR approach to work. When I did some tests with Chromium last year they seemed to show that an iframe runs in the same thread as its parent window. I wasn't testing XHR though, just animation.
So if you ever do try this out, I would be interested to hear the results. Thanks!
If you really wanted to, I think you could set up an endpoint on your server to be long polled with synchronous XHR in a while loop, while you set up the popup in an iframe. When the popup is clicked, you send a notification to the server so the next synchronous request returns 200 and you dispose of the iframe.
On searching, I discover someone else has had this crazy idea already - http://stackoverflow.com/questions/16934667/what-methods-are...