Window.unload triggers post after unload
javascript, jquery, ruby-on-rails
Solution
Try the `beforeUnload` event
The exact handling of the unload event has varied from version to version of browsers. For example, some versions of Firefox trigger the event when a link is followed, but not when the window is closed. In practical usage, behavior should be tested on all supported browsers, and contrasted with the proprietary beforeunload event.
- https://developer.mozilla.org/en-US/docs/DOM/window.onbeforeunload
UPDATE
The unload event is triggered when the page has unloaded.
- https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest/Synchronous_and_Asynchronous_Requests#XMLHttpRequests_being_stopped
UPDATE 2
To disable the `Are you sure that you want to leave this page?` popup try returning `null` from the `beforeUnload` callback function
- How to show the "Are you sure you want to navigate away from this page?" when changes committed?
UPDATE 3
Check this for cross-browser compatiblity
- http://jonathonhill.net/2011-03-04/catching-the-javascript-beforeunload-event-the-cross-browser-way/
Problem
I am trying to do a post to server before unloading a page and I followed this and it's working fine. My problem is the $.post on window.unload is triggered after it has unloaded. I tried it with a signout link and checking on my logs, I get the following: ``` Started GET "/signout" for 127.0.0.1 at 2012-11-22 00:15:08 +0800 Processing by SessionsController#destroy as HTML Redirected to http://localhost:3000/ Completed 302 Found in 1ms Started GET "/" for 127.0.0.1 at 2012-11-22 00:15:08 +0800 Processing by HomeController#index as HTML Rendered home/index.html.erb within layouts/application (0.4ms) Rendered layouts/_messages.html.erb (0.1ms) Completed 200 OK in 13ms (Views: 12.9ms) Started POST "/unloading" for 127.0.0.1 at 2012-11-22 00:15:08 +0800 Processing by HomeController#unloading as */* Parameters: {"p1"=>"1"} WARNING: Can't verify CSRF token authenticity Completed 500 Internal Server Error in 0ms NoMethodError (undefined method `id' for nil:NilClass): app/controllers/home_controller.rb:43:in `unloading' ``` First part is the signout and then user gets redirected to root then it runs the post ('/unloading'). Is there a way to make the '/unloading' execute first then execute whatever the unload action was? I have this as my jquery post ``` $(window).unload -> $.ajax { async: false, beforeSend: (xhr) -> xhr.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content')) , url: '/unloading' , type: 'Post' , data: { p1: '1' } } ``` Update So I did transfer the ajax request to beforeunload and it was working but I had to do a `return null` to remove the dialog box appearing because if I don't, the ajax was still triggering on popup of dialog (even without answering "yes/no i want to leave this page"). Result is this: ``` window.onbeforeunload -> $.ajax { async: false, beforeSend: (xhr) -> xhr.setRequestHeader('X-CSRF-Token', $('meta[name="csrf-token"]').attr('content')) , url: '/unloading' , type: 'Post' , data: { p1: '1' } } return null ``` Also, I have only tried it with Chrome for now and it's working as expected. Yet to try on other browsers.