RE: [aspectwerkz-user] Hot deployment questions

Hi Alex,

> -----Original Message-----
> From: Alexandre Vasseur [mailto:[email protected]]
> Sent: lundi 11 avril 2005 09:36
> To: [email protected]
> Subject: Re: [aspectwerkz-user] Hot deployment questions

[snip]

> 1/ accessing the definition model to get the scope
> should be :
>  DeploymentScope scope =
> SystemDefinitionCONTAINER.getDefinitionFor(loader,
>  systemId).getDeploymentScope("toString");
> No new() - that would not do anything.

Ok cool, then http://aspectwerkz.codehaus.org/dynamic_aop.html needs to be
fixed.

BTW you mentioned last time that you would fix it to make it clear that
aop.xml was required. That said, I've found that it works without aop.xml
(at least in some cases), see below.

Also, the "Deployment scopes" section is not clear where it says that the
scope can be defined in aop.xml or in an annotation:

- The sentence " They are needed due to the fact that no JVMs today support
schema redefinition when redefining your classes." should be improved to
better explain what it means.

- It should be more clearly stated whether defining the deployment scope in
the code also requires an aop.xml file or not.
 
> 2/ aop.xml is mandatory in all cases

My example works without an aop.xml file... :-) I'd really like to know when
an aop.xml file is required and when it isn't. It seems that if you don't
use a deployment scope it might not be required?

> If the scope is defined as an annotation, ie in an aspect, then it is
> mandatory to declare the aspect in aop.xml

Ok. I haven't tried this yet. This is should be clearly documented in
http://aspectwerkz.codehaus.org/dynamic_aop.html
 
> > Thus it seems possible not to have anything defined in aop.xml. Thus
> > something like this would work, right?
> >
> > <aspectwerkz>
> >  <system id="cactus2"/>
> > </aspectwerkz>
> >
> 
> No, won't work (nothing would be prepared for the scope to be further
> used)

It did work but probably because I was not using a deployment scope and that
probably worked only because the hot deployment is done before my weaved are
loaded. 

So I think you're right in the general case where a deployment scope is
required, then an aop.xml file is required.
 
> > 3/ Would it also work if I have a generic deployment scope such as:
> >
> > <aspectwerkz>
> >  <system id="cactus2">
> >    <deployment-scope name="allcode" expression="within(..)"/>
> >  </system>
> > </aspectwerkz>
> >
> 
> 3/ generic scope is supported (and that s the motivation of it: allow
> deployment to a subset of that scope upon user/app needs but thus
> under control by the deployer)
> Yes, very generic scope should work. The idea there would be to deploy
> to a subset of this wide scope

Ok, cool. Actually this syntax did not work but I'll try again with another
syntax.

[snip]

> Should we write a more comprehensice tutorial on that ?

I think improving the http://aspectwerkz.codehaus.org/dynamic_aop.html page
would help a lot :-)

It's a complex topic (with lots of options) and wherever I look
(documentation, blog posts, etc) there are lots of ambiguous statements. In
other words I was not able to find a single document that clearly described
all the possibilities and the required configuration.

Thanks
-Vincent