Re: inheriting pages in page flows

Thu, 23 Jun 2005 16:44:08 -0700

I think the confusion is about what paths are inherited. Forwards (and SimpleActions) are the only things that specify paths. If you override an inherited action, you wouldn't be inheriting its forwards at all, so you'd only have the ones you defined on the inherited action. Here's an example: 

/base/BaseController.jpf:
---
@Jpf.Controller(
   simpleActions={
       @Jpf.SimpleAction(name="simple1", path="base_simple1.jsp"),
       @Jpf.SimpleAction(name="simple2", path="base_simple2.jsp")
   }
)
public class BaseController
{
   @Jpf.Action(
       forwards={
           @Jpf.Forward(name="complex1", path="base_complex1.jsp")
       }
   )
   public Forward complex1()
   {
       ...
   }

   @Jpf.Action(
       forwards={
           @Jpf.Forward(name="complex2", path="base_complex2.jsp")
       }
   )
   public Forward complex2()
   {
       ...
   }
}

/derived/DerivedController.jpf:
---
@Jpf.Controller(
   simpleActions={
       @Jpf.SimpleAction(name="simple2", path="derived_simple2.jsp")
   },
   inheritLocalPaths=true
)
public class BaseController
{
   @Jpf.Action(
       forwards={
           @Jpf.Forward(name="complex2", path="derived_complex2.jsp")
       }
   )
   public Forward complex2()
   {
       ...
   }
}
Here's a table of actions/destinations (all actions being raised in the context of /derived): 

   simple1       /base/base_simple1.jsp
   complex1      /base/base_complex1.jsp
   simple2       /derived/derived_simple2.jsp
   complex2      /derived/derived_complex2.jsp

Does this answer your question?
Rich 
John Rohrlich wrote:


By at that level I mean in the directory of the page flow with the
overriding action.

also see inline comment

- john

-----Original Message-----
From: Rich Feit [mailto:[EMAIL PROTECTED] Sent: Thursday, June 23, 2005 2:59 PM 
To: Beehive Developers
Subject: Re: inheriting pages in page flows
I'm not sure what you mean by "at that level" -- are you asking whether overriding an action implies that you have to create a JSP that's associated with the derived page flow? If so, the answer is no -- that's the whole point behind the idea of inheriting JSPs. But I'm probably misunderstanding what you're asking. :) 

[JR] If the answer is no then I'm not sure how this is different from
what I originally suggested. If you don't need to add a JSP if you
override then how do you know if the local path is present? You are
suggesting that the annotation be at the class level which leaves open
the possibility that some JSPs will be local and some will be in the
directory of the base class page flow.

Suppose you have two actions that you override. In case one you forward
to foo.jsp which is found local to the base page flow. In case two you
forward to bar.jsp and you add a bar.jsp in the directory of the
extending page flow

baseFlow/
                foo.jsp
                bar.jsp
extendingFlow/
                bar.jsp


From what you've said so far I'm not certain what happens. I belive that

if I set inheritLocalPaths=false then the action forwarding to foo.jsp
will fail from the extending page flow. If I set inheritLocalPaths=true
then I would expect foo.jsp to be found. But what about the action
forwarding to bar.jsp? I assume that I get the one in the extending flow
directory in both cases (true or false). 
If you don't follow this maybe you could set up your own example to
better explain your design.

thanks - john


John Rohrlich wrote:


So are you saying that overriding an action means also adding a jsp at
that level?

- john

-----Original Message-----
From: Rich Feit [mailto:[EMAIL PROTECTED] Sent: Thursday, June 23, 2005 2:44 PM 
To: Beehive Developers
Subject: Re: inheriting pages in page flows

Hi John,
I agree that this would be ideal, but I don't think it's possible (should have made it clear in the original email). There's no way at build time to know for certain whether a local path is "present", and there's also no way at runtime to know if it's "present" beyond trying to hit it and looking for a 404 result. This is true for JSPs as well as for other arbitrary Servlet paths. 

Rich

John Rohrlich wrote:




A good start Rich, but I'd like to see some additional behavior.

Allow action overrides to use pages local to the overridden actions

page



flow directory if the page is not found local to the overriding class.
This should work for n levels of inheritance. If class B extends class
C, and class A extends class B, and both extending classes override

the

same action then you would first look for a jsp in A's directory. If

you



didn't find the jsp you would look in B's directory and then finally

C's



directory.

- john



-----Original Message-----
From: Rich Feit [mailto:[EMAIL PROTECTED] Sent: Thursday, June 23, 2005 11:13 AM 
To: Beehive Developers
Subject: inheriting pages in page flows

Hi all,
I'd like some design feedback here. http://issues.apache.org/jira/browse/BEEHIVE-400 deals with a 
much-asked



question: if you have a page flow that inherits from another page

flow,
how can you also inherit pages from the base page flow? Currently, there's no good way to do it, which is an obvious hole. My thought is 


to do something really simple (from the user's point of view :) ),

like




have a class-level annotation attribute:

 inheritLocalPaths=true
This would cause local paths in *inherited* actions to be used in the context of the current page flow. I think this might be sufficient, 
and
even if it turns out it's not, it seems like a good start. Any thoughts/comments on this? 

Thanks,
Rich

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