Re: [cgiapp] Re: register_hooks() proposal

[William McKee <suppressed>]

On Sat, Sep 25, 2004 at 02:00:08AM +1000, Cees Hek wrote:
> The terminology is somewhat confusing, and I've confused myself a couple of
> times while writing these messages to the list :).  Here is how I see it:

Glad to know it's not just me :). Thanks for the concise explanation.
The example you provided really helped clear things up for me. I guess
programmers can read code better than language; or perhaps codes has
more depth of meaning than expositions.


> A hook is a place in the execution path of a program where you can execute a bit
> of your own code.  So the cgiapp_init and cgiapp_prerun methods are examples of
> hooks into the execution path of a CGI::App program.  We are looking to add the
> ability to execute multiple bits of code at each hook.  I prefer to think of
> these bits of code as callbacks.  So we can register multiple callbacks at each
> hook.  We also want to be able to specify the order that the callbacks get
> executed in.

So we have hooks that contain callbacks which execute in some order (one
of default, first or last).


> I think it might clear things up if we actually call the hooks like
> this (init prerun postrun teardown)...

+1


> So as an example, the cgiapp_prerun callback will automatically be registered at
> the prerun hook with the default ordering (DONTCARE).  
> 
> Now if later on in the code another callback is registered at the prerun hook,
> it could be done like this:

So this would allow existing code that overrides the callback subroutine
to work while allowing new callbacks to be added. Nice! Now I'm starting
to grok this addition.

I think it would be helpful in your documentation update to include a
use case. Here's why: under "normal" operation, should a programmer
override the cgiapp_init subroutine or add a new callback? My guess is
to stick with existing behavior. What's your opinion?


> I hope that clarifies the terminology a little bit.  I am in the process of
> solidifying these ideas in a couple of new plugins, and I hope to have these
> available soon.

Looking forward to it.


William

-- 
Knowmad Services Inc.
http://www.knowmad.com

---------------------------------------------------------------------
Web Archive:  http://www.mail-archive.com/suppressed/
              http://marc.theaimsgroup.com/?l=cgiapp&r=1&w=2
To unsubscribe, e-mail: suppressed
For additional commands, e-mail: suppressed