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Subject: [axis] Smart(er) Handlers
From: Richard Sitze <rsitze@us.ibm.com>
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 <OFFAC4717C.4EDA115E-ON86256C40.0053D05F-86256C40.005558E0@us.ibm.com>
Date: Thu, 26 Sep 2002 10:32:13 -0500
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Given a list of handlers to load:

        H1, H2, H3

in WSDD, what I'm proposing is that the runtime query each handler as it 
identifies it in a service configuration and *ask* the handler if it wants 
to be loaded in the current environment:

        if (handler->isEnvironmentallyFriendly())
                put handler in chain...

Semantically, we can do the same thing by letting the handler (when 
called) return immediately IF it doesn't have anything to do.

Why:
        - I'm a performance bigot, and if the handler isn't going to *do* 
anything, then I don't want it called.
        - It's easy to code.

Example 1:
        A Service Handler: verify that required service/classes are 
(loadable) and disable handler if not.

Example 2:
        Debug Handler: enable only if debug-mode ON


****

So, having put some effort into trying to give you an example (I can't 
really SAY what my internal requirements are, now can I :-), it stricks me 
that a reasonable and cool alternate might be:

        realHandler = configuredHandler->getRealHandler();
        if (realHanderl != null)
                put realHandler in chain...

[names should be changed to protect the innocent..]

Default behaviour is getRealHandler() { return this; }

So, the method getRealHandler can act as a factory...  a security handler 
could return a 64 or 128 bit security scheme.


*******************************************
Richard A. Sitze
IBM WebSphere WebServices Development