Re: Self-configuring classes

Lew <lew@lewscanon.nospam>
Fri, 03 Aug 2007 19:02:39 -0400
Chris wrote:

I'd like a developer to be able to be able to write his own class that implements one of our interfaces. The developer would then register the class with our app which would use it. Our app would discover what configuration parameters the class needed, and then throw up a page in our UI so an end user could fill them in.

Jini, JNDI and Web services UDDI are stabs at this same target. Arguably, so
is EJB. The Spring framework and the pattern called "Inversion of Control".

The question is, what is the best way for the class to tell the app
what parameters it requires? Are there any good design patterns for this?

One way is to let the component handle its own initialization.

All the extant approaches of which I'm aware work off the concept of a
registry or a set of descriptors that map implementations to their
abstractions. Many involve a run-time discovery process similar to or based
on reflection. JavaBeans property sheets come to mind.

Just for starters.


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