I don't know why you were being downvoted but I don't think -anything- should ever be able to block the execution thread. I never liked the fact that you could force lock a user by spamming alert/confirm boxes and I saw this effect as a bug of the default behavior of the operating system over a feature of the browser.
I used to work in applications that require you to do -as much as possible- to keep the window open. This isn't for spam reasons, it is because we did assessment and you really, really didn't want someone closing half-way through an assessment, especially one that is timed. You also don't want to freeze the timer because you might leave the user an opportunity to cheat (close window, research, relaunch assessment, repeat).
So this was real example of something that really should be single-execution. However, even with all the popups, checks, refresh-push-forward, launch-window-on-exit hacks we tried we STILL got users lost out of the system. Not only that but we wound up annoying/angering/confusing 1000 users for every 1 user it helped.
shrug
YMMV, but I believe 99.999% of all issues can be solved with user/session caches and clear wording over blocking the execution thread.
I used to work in applications that require you to do -as much as possible- to keep the window open. This isn't for spam reasons, it is because we did assessment and you really, really didn't want someone closing half-way through an assessment, especially one that is timed. You also don't want to freeze the timer because you might leave the user an opportunity to cheat (close window, research, relaunch assessment, repeat).
So this was real example of something that really should be single-execution. However, even with all the popups, checks, refresh-push-forward, launch-window-on-exit hacks we tried we STILL got users lost out of the system. Not only that but we wound up annoying/angering/confusing 1000 users for every 1 user it helped.
shrug
YMMV, but I believe 99.999% of all issues can be solved with user/session caches and clear wording over blocking the execution thread.