Re: Interesting Observation

I've been experimenting.

As expected these don't work:

<span jwcid="@PageLink" page="framework:contrib/inspector/Inspector"/>

and

<span jwcid="@PageLink" page="contrib/inspector/Inspector"/>

I know the first wouldn't work as "framework" is special and not can't
be referred to in this way.

I was worried about the second as one of the page lookup rules is
"check the framework" and contrib/inspector/Inspector is a valid path
relative to Framework.library.

I see now how the framework is protected from this, again by it's
special status.

I was able to do this though:

<span jwcid="@PageLink" page="contrib:inspector/Inspector"/>

Tapestry finds/instantiates the page ok but subsequently breaks as
Inspector's implementation won't work if the page is referenced in
this way.

And I was able to show that references to the components in Inspector
can be made  **without** adding

<library id="inspector"
        specification-path="/org/apache/tapestry/contrib/inspector/Inspector.library"/>

to the application file. As long as Contrib is in there:

@contrib:inspector/ShowEngine - is legal

And now I have all the interesting engine 'stuff' in my page.

Geoff









On 2/19/06, Geoff Longman <[email protected]> wrote:
> Did you know that the namespaces for Framework and Contrib overlap?
>
> I'm writing some code to detect when namespaces (based on the location
> of the spec file) overlap and as a lark I added a test case that
> checks if Framework and Contrib clash. They do.
>
> Of course Framework is "special" and you couldn't exploit the overlap like this:
>
> @framework:contrib/components/Choose
>
> and Contrib.library is a package below Framework. You can't refer to a
> framework component from contrib unless this was legal:
>
> @contrib:../form/Button [General Q] illegal in classpath? - what about
> in the context?
>
> So I guess it's no big deal. But an interesting example of the
> boundary crossing stuff I've been blathering about lately.
>
> Note though that user libraries do not have the special status of
> Framework and thus no protection from strange behaviour based on name
> choice.
>
> ahh, but the following are both legal even though the inspector
> library is 'private' to Contrib.
>
> @contrib:inspector/DumpObject
> @contrib:DumpObject
>
> In that case no immedaite ill effects would be observed as both
> libraries refer to the same .jwc file and the meta's for
> 'org.apache.tapestry.component-class-packages' are the same in both
> Contrib.libary and Inspector.library. ie:
>
>   <meta key="org.apache.tapestry.component-class-packages"
> value="org.apache.tapestry.contrib.components"/>
>
> I think this is a very unusual case though as I've not seen two
> libraries declare the same component this way.
>
> These are also legal and serve only to expose components/pages  in
> Inspector that are not for public use:
>
> @contrib:inspector/ShowProperties
> @contrib:inspector/ShowDescription
> @contrib:inspector/ShowEngine
>
> <span jwcid="@PageLink" page="contrib:inspector/Inspector"/>
>
> etc.
>
> Geoff
>
> --
> The Spindle guy.          http://spindle.sf.net
> Get help with Spindle:
> http://lists.sourceforge.net/mailman/listinfo/spindle-user
> Blog:                     http://jroller.com/page/glongman
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>


--
The Spindle guy.          http://spindle.sf.net
Get help with Spindle:   
http://lists.sourceforge.net/mailman/listinfo/spindle-user
Blog:                     http://jroller.com/page/glongman
Feature Updates:          http://spindle.sf.net/updates