Calling BSP application in same session

Question

Hi,
I am trying to arrange a few BSP pages into some sort of "BSP pool" so I can call them from different applications. Means: I want to create something like a few base objects to re-use in other BSP applications. My BSP applications have to be stateful - so when I embed those pool pages (using iframe or similar technology) I do get a new session and cannot share the model data. :-((
Is there any way of avoiding this session problem? Can I force a call to a new URL (on the same server) to re-use my previous session?
Interface method "IF_BSP_NAVIGATION->goto_page" sports a parameter "session", but this parameter does not what I would have expected when fed with the current session ID.
I could not find any documentation on the session handling in the WAS either. All I learnt is that a new session seems to be created whenever a URL with a different ICF path is called - even on the same server. If this is the case I will definitely have problems pooling BSP pages into a "toolbox" BSP application.
Sharing the model data via server-side cookies could be a way, but fails for object references (like class instances or data references).
Any experience with writing the model data (and references!) into ABAP memory to be re-used in the same GUI session (e.g. CIC)? That might be a workaround (?).
Any hint greatly appreciated.
TIA
Peter

Answer 1

I can tell you what I have used in the pass to acomplish this: BSP Extension Elements or Reusable Controller classes. 
BSP Extensions are really designed for just this kind of reusability.  You have static interface into and out of the extensions.  All the rendering is encosed in the extension, yet will be befored in-line in the rendering of the main page.  You don't have to worry about separate sessions, or the overhead of iFrames.
Another very similar approach is to create reusable controller classes.  Rendering logic can actually be placed in the controller as well (instead of calling a view). Brian McKellar has an SDN Weblog on how to use a controller class to build a pattern engine.
If you are really trying to create a reusable toolbox - then I highly suggest the Extension approach.  However I have done the sharing of model data between two applications.  I have an example here:
/people/thomas.jung3/blog/2005/05/27/custom-bsp-extension-element-for-field-level-help
Basically I serialize the model class and write it into a server cookie.  Then I pass a unquie ID for that model instance to the second application.  It can then retrieve and deserialize the model.