Interception in Flowscript (was: [RT] Improving Sitemap and Flowscript)

[Reinhard Pötz <re...@apache.org>]

From: Christian Haul [mailto:haul@informatik.tu-darmstadt.de] 

> >   Interception in Flowscript
> >  ----------------------------

> > Something that can be modelled very well as an aspect is 
> > authentication/authorization (aka login) because it's not
> something that
> > is part of the webapp (at least, it shouldn't be!) but it's
> something
> > that is "wrapped" around it to allow people to access it
> without the
> > proper authorization.
> 
> Here I like to disagree, sort of. While I agree that
> authentication is a 
> good use case for AOP, I don't come to the same conclusion. 
> In fact, by 
> using an action to protect a complete URI space very much the 
> same can 
> be achieved. I know, actions are not liked by everyone, but 
> this is one 
> of the best applications for them.
> 
> So, please provide a more convincing use case for the introduction of
> AOP in Cocoon ;-)


(Warning: the concept of AOP is rather new to me ...)


When we polished the FOM some weeks ago we talked a lot about 

 - pooled components

I think AOP would be a great advantage because I only have to 
implement it once to get a Hibernate session and releasing it.


Other use cases are 

 - customized flows that have user exits without having to change 
   the core flow
 - maybe error handling
 - logging 
 - ... and of course authentication/authorization because I like to 
   have it within the flow because IMHO applications are very easy 
   to understand if the whole logic can be found at a single place.


I think these are some good reasons and worth of thinking more about
integrating AOP in flow.


Cheers,
Reinhard