RE: [picocontainer-dev] The Visitor on Pico

> 	I've never liked this.  I mean I like the visitor pattern for
> things like ASM, but it seemed gratuitous to shove it into Pico back in
> the day.
> 
> 	Originally Lifecycle's breadth first start() was tied to it.
> Then we put in a more conventional traversal.
> 
> 	Why don't I like it ?
> 
> 	Consider that child containers can choose different CAF,
> Lifecycle, Montor to parents.  They can also not register themselves
> with parent, so even start/stop does not cascade.
> 	The visitor concept seems to transcend these choices.  Indeed, a
> container cannot block/veto visiting.
> 
> 	I know people use this - can they speak up and give real world
> examples?  Pete ?
> ________________________________
> 
> The visitor is not used for the LC anymore, but it is used e.g. in
> remoting to collect the JMX enabled components. But I have to admit,
> that even there the process is not optimal (have a look at the efforts
> to avoid double registration).
> 
> The visitor is great for inspecting the Pico related structure though
> and might help to build a GUI.

What about the VerifyingVisitor?  

I use that regularly, and I yes, I use it for GUI-ish work.

I also tended to use it when implementing simple custom lifecycles, but I'm
sure there's other (better!) ways to do that.

I certainly don't mind, however, demoting the acceptVisitor() methods to the
Mutable pico only.  To me, the visitor is only really good for
management/privileged operations, and shouldn't belong in the sealed
container.

Would that compromise work? 
	
-Mike
 




---------------------------------------------------------------------
To unsubscribe from this list please visit:

    http://xircles.codehaus.org/manage_email