How to stall onunload event to finish ajax script first?

[tuktik]

Hello everyone,

I want to notify user if he modifies some data in the form and leaves the page without saving. So I use onunload event to call ajax file to check if the data in the form elements are different from the one in the database, and make an alert message to notify user. I found that my ajax script have not finished the process but the browser already loaded a new page and the user will never see the alert message.

Are there some ways to stall browser until the ajax script finishes?

[rnd me]

Hello everyone,

I want to notify user if he modifies some data in the form and leaves the page without saving. So I use onunload event to call ajax file to check if the data in the form elements are different from the one in the database, and make an alert message to notify user. I found that my ajax script have not finished the process but the browser already loaded a new page and the user will never see the alert message.

Are there some ways to stall browser until the ajax script finishes?

a warning alert box usually buys you enough time.
IE has a onbeforeunload that works better for that kind of thing.

some browsers let setTimeout delayed strings stick around, even after the page is long gone, but i don't remember any specifics...

if you are not worried about user annoyance, as in this is something for work, popup a new window onunload, and update with that.

[acoder]

You could also try making the Ajax script synchronous.