Preloader: executing code asynchronous

[Olivier_S]

Dear experts,

I'd like to make a preloader for a heavy bsp which displays the steps being executed.

Basic scenario:

Client side, I want to make one ajax call to start the server side processing, after which a periodic (every x seconds) ajax call is made to retrieve the step currently being processed. Once the ajax call receives a signal the execution has ended, it redirects to the next page.

The steps are currently being tracked by making use of the shared buffer.

Problems/questions:

How to execute code asynchronously? The only clue I've found is to call a function module in a background task.

Is it possible to use the shared buffer's variables in a different task? When I use an FM in a background task to export to the shared buffer, I can't seem to import the values in the main code. Are there alternatives aside from a database table?

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An example of the shared buffer code and FM in background task can be found here:

http://pastebin.com/m37b505a0

Edited by: Olivier Schietecat on Sep 9, 2009 11:22 AM

[Olivier_S]

Decided to look back on this question, and close it.

The easiest way to make a preloader was to not do it asynchronous, but to use ajax to make each load of an object a separate http call.

This method of course, is only useable when doing custom code, so you can adjust its flow to it.

Having done other server-side scripting languages, I wish the http plugin was able to do this asynchronously. I guess this belongs to my wishlist, such as: "correct usage of back and forth browser buttons", "use html 5 for making sap mobile" and "separate html and css", "limit the usage of frames".