Re: [aspectj-users] intercept Class but not SubClass

["Charles N. Harvey III" <charlieh@xxxxxxxxx>]

Ron,
First, thanks for the tip yesterday, very slick.  Every day that I learn 
more AspectJ
I marvel at how code can be written so elegantly.

Second, I have a question about the difference between call and 
execution.  I want to
be using call because I want my aspect to intercept into the calling 
class, not the
class that is getting executed.  That said, does call return the 
instantiated object?
I tried running:

public aspect MyAspect
{
   pointcut myIntercept() : call( MyClass.new() ) &&
                            !within( MyAspect ) &&
                            !this( MySubClass.new() );

   after() : myIntercept()
   {
       MyClass mc = (MyClass)thisJoinPoint.getTarget();
   }
}

But when I "getTarget()" the object is null.  Is this because only the 
call has been
made and the object hasn't actually been created yet.  That is what I am 
lead to believe.
I used execution but after reading the FAQ entry I see that my intercept 
is going into
MyClass and not the class that is calling MyClass.

Should I be using "initialization" instead?  I want the aspect placed in 
the calling class
but I need to use the instance of the object that I am making a call 
to.  Does this make
sense?  I think I am confusing myself.

Thanks again.


Charlie




Ron Bodkin said the following on 6/9/2004 7:45 PM:

> See also the a FAQ entry on the differences between call and execution join points to determine which is the right one to use in a given scenario: http://dev.eclipse.org/viewcvs/indextech.cgi/~checkout~/aspectj-home/doc/faq.html#q:comparecallandexecution
>
>  
>
> > ------------Original Message------------
> > From: Wes Isberg <wes@xxxxxxxxxxxxxx>
> > To: aspectj-users@xxxxxxxxxxx
> > Date: Wed, Jun-9-2004 4:10 PM
> > Subject: Re: [aspectj-users] intercept Class but not SubClass
> >
> > To add to what's said,
> >
> >   call(MyClass.new())
> >
> > will pick out a constructor-call join point
> > but not the corresponding constructor-execution join point,
> > which as Ron points out runs when subclasses are being
> > initialized.
> >
> > (As for what the pointcuts mean, I encourage you{/me/everyone}
> > to closely read the programming guide semantics appendix.
> > 30-90 minutes spent really absorbing those definitions will
> > pay off a lot in avoiding common mistakes.)
> >
> > Wes
> >
> > Charles N. Harvey III wrote:
> >    
> >
> > > Hello.
> > > I have written a simple aspect to run after MyClass.new is executed.
> > > Thing is, I also have MySubClass which extends MyClass.  And the aspect
> > > seems to be intercepting that as well.
> > >
> > > public pointcut myCutting() : execution( MyClass.new() ) && !execution( 
> > > MySubClass.new() );
> > >
> > >
> > > That doesn't seem to be doing it.  Is that correct or is there some other
> > > way to make sure that no sub-classes get intercepted?
> > >
> > > Thanks a lot.
> > >
> > >
> > > Charlie
> > >
> > > _______________________________________________
> > > aspectj-users mailing list
> > > aspectj-users@xxxxxxxxxxx
> > > http://dev.eclipse.org/mailman/listinfo/aspectj-users
> > >
> > >      
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> >
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