[seam-dev] qualified bean names

[Dan Allen]

On Fri, Apr 9, 2010 at 10:53 AM, Pete Muir <pmuir at redhat.com> wrote:

> * Changed the requirement to be to use org.jboss.seam.* as the prefix for
> the bean name. We will add an extension for CDI that allows aliasing
> namespaces such as org.jboss.seam to a short prefix (such as seam.). Anyone
> fancy coding this up quickly for Weld Extensions?
>

I missed this one. We had a long chat about this in #seam-dev a few weeks
ago and drew these conclusions.

Using long qualified bean names (i.e.,
@Named("com.acme.framework.module.beanName")) immediately introduces the
need to shorten (or import) them in someway. The approach that was taken in
Seam 2 was to qualify every name with the prefix "org.jboss.seam." and then
add all of these namespaces to a list of auto-imports in jboss-seam.jar. But
that defeated the whole purpose of having a qualified name since now each
component had two names, the short one (e.g., "statusMessages" and the long
one "org.jboss.seam.international.statusMessages"). So global imports
provided by the library are meaningless.

That brings us to local imports. Since bean names are only meant to be used
in the EL (which in most cases is the view), we ask, how to we import the
names in the view? I posed this very question to Lincoln. I suggested:

<s:importNames namespace="org.jboss.seam.faces"/>

Understandably, he challenged me by saying (paraphrase) "you must be doing
something wrong if you need that".

We came to the understanding that having a protected namespace is good, but
having a namespace that you can't easily type is bad. We concluded that
since we "own" the Seam name, people should be willing to accept that we can
prefix our names with "seam" and that should be enough to ensure that they
don't conflict with application names. In the example above, I can avoid the
import by using the name:

seam.statusMessages

I think bean names should be unique across all our modules so we can avoid
having to put the module name in the bean name
"seam.international.statusMessages". You can always tweak the name to make
it unique.

The question we need to ask, is, why not?

-Dan

-- 
Dan Allen
Senior Software Engineer, Red Hat | Author of Seam in Action
Registered Linux User #231597

http://mojavelinux.com
http://mojavelinux.com/seaminaction
http://www.google.com/profiles/dan.j.allen
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