RE: [aspectj-users] after advice with overridden methods

["Lendvai Attila" <Attila.Lendvai@xxxxxxxxxxx>]

:: I think the aspect is behaving correctly.
:: 
:: Programming Guide, Semantics appendix:
:: 
::    At a method execution join point, the signature [is]
::    a method signature whose qualifying type is the
::    declaring type of the method.
:: 
:: So a method-execution pointcut will match not only the 
:: declaring type, but also any implementation of that method 
:: (i.e., any overriding methods).
:: 
:: Rather than cflow, try
:: 
::     execution(void init()) && within(A)
:: 
:: This is staticly-determinable (read: more efficient).
:: 
:: You might also prefer to use call(..).


i'm still having trouble...

- i can't use call() because the method is called from a different jar
(it's Echo's void Component.init()). i would not use injars if possible.
- using within(A) is problematic because A varies over several classes.
and if i forget to list one of my subclasses then it silently won't work
for that class. i hate such error-prone solutions. (not to mention that
there would be several such within(A)'s)

for the big picture: i subclass various components that come from a
Echo's jar, and in a mixin-like aspect i declare an after advice on a
method named init() (gets called by the framework when the component is
added). i would like to have an  advice run once, and only once for all
of my component subclasses on which the aspect is applied. but i
subclass my components further, so simply by execution(void
Component+.init()) the advice runs as many times as i subclass my first
class in the inheritance tree.

having a special execution() and this() combined pointcut would help. in
fact two of them, one that catches the most specific version of the
method, and one that catches the most general one (from those that are
visible for the weaver of course).

btw, i couldn't solve it with cflow() variants either, but it could be
my limitation. in some cases, that i can't identify, the advice didn't
run.

any ideas?

- 101



:: 
:: Wes
:: 
:: Lendvai Attila wrote:
:: > hello all,
:: > 
:: > if i have the following setup: (three classes, extending 
:: each other 
:: > and overriding a function)
:: > 
:: > class A
:: > {
:: >         void init()
:: >         {
:: >                 System.out.println("A.init()");
:: >         }
:: > }
:: > 
:: > class B extends A
:: > {
:: >         void init()
:: >         {
:: >                 System.out.println("B.init()");
:: >                
:: >                 super.init();
:: >         }
:: > }
:: > 
:: > class C extends B
:: > {
:: >         void init()
:: >         {
:: >                 System.out.println("C.init()");
:: >                
:: >                 super.init();
:: >         }
:: > }
:: > 
:: > private static aspect Chain {
:: >         pointcut f() : execution(void A.init());
:: > 
:: >         after(A a) : f() && this(a)
:: >         {
:: >                 System.out.println("After init, this [" + a + "] 
:: > thisJoinPoint [" + thisJoinPoint + "]");
:: >         }
:: > }
:: > 
:: > 
:: > in the main:
:: > 
:: > C c = new C();
:: > c.init();
:: > 
:: > output:
:: > 
:: > C.init()
:: > B.init()
:: > A.init()
:: > After init, this [com.netvisor.nvsr.client.Factorial$C@1fc2fb]
:: > thisJoinPoint [execution(void 
:: > com.netvisor.nvsr.client.Factorial.A.init())]
:: > After init, this [com.netvisor.nvsr.client.Factorial$C@1fc2fb]
:: > thisJoinPoint [execution(void 
:: > com.netvisor.nvsr.client.Factorial.B.init())]
:: > After init, this [com.netvisor.nvsr.client.Factorial$C@1fc2fb]
:: > thisJoinPoint [execution(void 
:: > com.netvisor.nvsr.client.Factorial.C.init())]
:: > 
:: > 
:: > 
:: > shouldn't be there only one After init message? note that it's 
:: > A.init(), not A+.init() in the pointcut! changing to A+ 
:: does not have 
:: > any effect on the output.
:: > 
:: > i can workaround the problem by adding && !cflowbelow(f()) to the 
:: > advice, but in a much more complex scenario it does not 
:: get called for 
:: > all the object i would like to... :(
:: > 
:: > so my question is: is everything ok with the above output?
:: > 
:: > thanks in advance,
:: > 
:: > 101
:: > 
:: >  
:: > 
:: >  
:: > 
:: > 
:: 
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