Method which is called by browser-close resp. session close

[mathias_essenpreis]

Hi,

When a user closes the browser or a session expires I need to call an unlock-method for some objects. This method should prevent that the lock for this object is always there.

Can you tell me how or is there another approach for this problem?

thanks

Mathias

[Former Member · Accepted solution]

Hi Mathias,

the browser sends an event on close (and unload) for which an event handler is registered in the WD runtime. This handler exits the corresponding component controller, which leads to a call of the wdDoExit() methods of the component and all dependant controllers. So it should be sufficient to put the "unlock" functionality you need into the wdDoExit methods of the controller(s) which locked the objects.

Hope that helps.

Regards

Stefan

[Former Member · Accepted solution]

Hi Stefan

I did a trace on the wdDoExit method and indeed it is called when the object is unloaded . But try doing a multiple refresh on the page and it is interesting to see that in some cases the wdDoInit of the next object is called before the wdDoExit method of the previous object is called and in some cases wdDoExit is never called and you would have to wait for Web Dynpro time out for these objects to actually be unloaded and release any connections they are holding.

Mathias : We too implemented locking via RFC but we saw that the user locks himself out if he does multiple refreshes(fast) on the same page , specifically because the wdDoExit is not being called and the lock not being released

Regards

Pran

[mathias_essenpreis · Accepted solution]

Hi,

thanks for participating. Well I think the situation you mentioned doesn't happen often, or?

And After a period of time (WD timeout) the wdDoExit is called, or?

So wdDoExit should work.

Regards

Mathias

[Former Member · Accepted solution]

Hi Pran,

ok, but what are the alternatives? I don't see any other possibility to "catch" the end of a session and do the cleanup/unlock. Any ideas?

Best regards

Stefan

[Former Member · Accepted solution]

Yep,

import com.sap.tc.webdynpro.services.session.IMaintainScope;
import com.sap.tc.webdynpro.services.session.IScopeListener;
import com.sap.tc.webdynpro.services.session.Utils;
import com.sap.tc.webdynpro.services.session.api.WDScopeType;

...

private void sessionSample()
{
  final IMaintainScope sessionManager = Utils.getScopeMaintainer( WDScopeType.CLIENTSESSION_SCOPE );
  sessionManager.registerToBeDestroyedListener
  (
    new IScopeListener()
    {
      public void scopeToBeDestroyed(IMaintainScope maintainScope)
      {  		
        /* Your cleanup logic here */
        maintainScope.unregisterToBeDestroyedListener( this );	
      }
    }
  );
}

WBR,

VS

[Former Member · Accepted solution]

Nope,

this is <b>not</b> a solution, i only see usage of non-public API except WDScopeType. Didn't your mother tell you not to use these?

Best regards

Stefan

[Former Member · Accepted solution]

Hi,

Thanks God my mom doesn't stay behind me when I'm typing this...

Conventional wisdom says that if somethig forbidden is very desirable, then it is allowed

Seriously, there is no way to do a LOT of things in WD without resorting to such API calls. I agree that these calls should be avoided at all cost, but...

1. How to use Servlet-like session without IScope?

2. How to intercept request/response cycle without IPhaseListener?

3. How to use ThreadLocal safely in WD (where java threads are allocated from pool and swaped between users) without ITask?

4. How to embedd arbitary component interface view dynamically without calls to addRelatedModelObject / setRelatedModelObject with hard-coded internal relation names?

5. How to replicate runtime repository content to external storage and further restore it on different server without refering classes in *.repository package?

6. How to... you may continue the list

Well, I need such functionality now and cannot wait till SP_XXX to be released in several monthes from now.

Regards,

VS

[Former Member · Accepted solution]

All nice and well. But you should not promote here in SDN a programming practice that is neither supported nor guaranteed to work over time.

Rule: Never use non-public Web Dynpro APIs or classes. Exceptions: none.

If you have proposals or requests, feel free to post them here.

Armin

[Former Member · Accepted solution]

Armin,

I firmly believe you understand, that it is more like complaining rather then promoting of BAD THINGS

VS

[Former Member · Accepted solution]

Psst Valery ... (read in whisper tone)

Dont let the guys above know but how did you figure out how to use them :B

[Former Member · Accepted solution]

Hello Valery,

could you please elaborate on the problems you found, perhaps for each problem in a separate thread?

Thank you.

Armin

[mathias_essenpreis · Accepted solution]

Hi Armin,

thanks for participating...

Do you have a solution for my problem?

Best Regards

Mathias

Message was edited by: Mathias Essenpreis

Sorry. I got an Exception after posting my question. Thus I thougt that my question wasn't posted.

[mathias_essenpreis · Accepted solution]

Hi Armin,

thanks for participating...

Do you have a solution for my problem?

Best Regards

Mathias

[Former Member · Accepted solution]

(Java Browsing Perspecive) + (JADClipse plugin) + Beer - (Free time)

VS

[mathias_essenpreis]

Hi Armin,

thanks for participating...

Do you have a solution for my problem?

Best Regards

Mathias