[Dojo-interest] Re: xdomain and synchronous calls

[tf]

Sten,

I've been using 

window.addEventListener("beforeunload", function_name, false)

to trap for a similar situation.  To be fair, it was recently brought to my attention that this is not working for one of our users and I suspect it is a browser compatibility issue with the beforeunload event, but I have not had time to investigate yet.

You may want to investigate the beforeunload event to see if it will work for you.  Perhaps you can trap that event and use it to make the asynch call?

Troy
  "Sten Duncan" <stenduncan at gmail.com> wrote in message news:8b78b9ae0702281029m3ac8323djce4f875b6caf1ce5 at mail.gmail.com...
  I am struggling with a problem involving cross-domain processing and the page unload action. 

  Briefly, when the user closes a page (onunload or onbeforeunload) I need to make an xdomain call to the server - to unregister the user. I don't know until the page is unloading that the call needs to be made so I can't do it in advance. The problem is that with an asynch call, once the thread is released after the io.bind call, the browser exits almost immediately and the server call never gets made.

  In a non-xdomain environment, this works fine since I can make the io.bind call synchronous. But in the xdomain environment, the io.bind is by definition asynch (I'm using the iframe proxy: XhrIframeProxy).

  I've also tried ways to pause the main thread to give the io.bind time to execute and return, but as we all know there is no "sleep" in Javascript. And if I use something like a timer (setTimeout) I have the same problem with the thread being released and the page exiting before the server call is made/completed. Putting the main thread into a loop doesn't help either - I get the popup telling me that a script appears to have stopped running, etc. and this is completely unacceptable for a user app. 

  Does anyone have any ideas about how to either:

  1. do a synchronous xdomain server call?
  2. pause the main thread so that an asynch xdomain call has time to return?

  Any help would be enormously appreciated. 




------------------------------------------------------------------------------


  _______________________________________________
  Dojo FAQ: http://dojo.jot.com/FAQ
  Dojo Book: http://manual.dojotoolkit.org/DojoDotBook
  Dojo-interest at dojotoolkit.org
  http://dojotoolkit.org/mailman/listinfo/dojo-interest
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://dojotoolkit.org/pipermail/dojo-interest/attachments/20070228/ddf7b96f/attachment.html