[jboss-user] [JBoss Seam] - seam conversations - conceptual design issues

[wschwendt]

Hello,

(first of all excuse my bad English).

when a conversationId is restored from the PageContext (this happens when a Faces request is received), the validateLongRunningConversation property of org.jboss.seam.core.ConversationPropagation is set to page.isConversationLongRunning().

Consequently, in the case of a long-running conversation, org.jboss.seam.core.Manager.restoreConversation() returns true or false, depending on whether or not the conversation was successfully restored.


In contrast,  when a non-faces request is received,  the conversationId  is retrieved from the request parameters and the validateLongRunningConversation of org.jboss.seam.core.ConversationPropagation remains false.

Consequently, in the case of a long-running conversation, org.jboss.seam.core.Manager.restoreConversation() always returns true, even when it was not possible anymore to restore the long-running conversation and a fresh temporary conversation was  therefore created instead.    (see the last line of org.jboss.seam.core.Manager.restoreConversation() ).
 // last line of org.jboss.seam.core.Manager.restoreConversation() 
  | 
  | public boolean restoreConversation() 
  | { ConversationPropagation cp = ConversationPropagation.instance();
  | ...
  | 
  |   return restoreAndLockConversation(ce) || !cp.isValidateLongRunningConversation();
  | }
  | 

It follows that for non-faces requests we don't have a validation of long-running conversations.  


  | class org.jboss.seam.jsf.SeamPhaseListener  {
  | ...
  | 
  |  /**
  |     * Restore the page and conversation contexts during a JSF request
  |     */
  |    protected void afterRestoreView(FacesContext facesContext)
  |    {
  |       FacesLifecycle.resumePage();
  |       Map parameters = facesContext.getExternalContext().getRequestParameterMap();
  |             ConversationPropagation.instance().restoreConversationId(parameters);
  |       boolean conversationFound = Manager.instance().restoreConversation();
  |       FacesLifecycle.resumeConversation( facesContext.getExternalContext() );
  | 
  |       // see my notes above:  For non-faces requests conversationFound is 
  | // always true, even if the conversation was actually not found  and a 
  | // temporary conversation was created
  |       if (!conversationFound)
  |       {
  |          Pages.instance().redirectToNoConversationView();
  |       }
  |  


I thought about what could be Gavin's intention that there is no validation of long-running conversations when a non-faces request is received. 
Perhaps the reason is that URLs are bookmarkable and the user could bookmark a URL that contains a conversationID of a long-running conversation.    If the user then makes a request with this bookmarked URL, he would not be able to access the corresponding page if the conversationID contained in the URL was validated.

But we pay a big price if we simply give up the validation of long-running conversations.        I think it would be much better if the last line of
org.jboss.seam.core.Manager.restoreConversation()  was simply as follows:



  |  // last line of org.jboss.seam.core.Manager.restoreConversation() 
  | 
  | public boolean restoreConversation() 
  | { ConversationPropagation cp = ConversationPropagation.instance();
  | ...
  | 
  |   return restoreAndLockConversation(ce);
  | }
  | 


In order to support bookmarkable URLs where a contained conversation ID should not be validated, we could simply add another request parameter to indicate that restoreConversation should return true even if the long-running conversation couldn't be successfully restored.

 
Please give us the same validation behavior for non-faces requests as we have for faces requests!


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