Re: Doubt - Policies and Invocation Chain

[Raymond Feng]

Sure. The Inteceptor is called on the "setNext()" method to receive the next 
interceptor in the chain. But the interceptor has freedom to decide if it 
should delegates to the next one.

For example, in the invoke(Message msg) implementation:

    // do something
    return getNext().invoke(msg);

or 
    // do something
    return myMsg;

Thanks,
Raymond


From: Douglas Leite 
Sent: Monday, October 19, 2009 11:15 AM
To: Tuscany-Developers 
Subject: Doubt - Policies and Invocation Chain


Hi,

I would like to know if is possible to invoke a specific method from a 
component inside an interceptor. For example, let's suppose the following 
scenario: A component CalcComponent that has the operations add and sub, and a 
reference to a AddComponent and a SubComponent. The add method uses the 
reference to the AddComponent to invoke the addMethod (that is part of the 
service interface of the AddComponent). The sub method works similarly to the 
add. Suppose that I am using some policy (like logging) in the add and sub 
methods.

The simplified invocation chain would work like that:

1) add -> Interceptor for the add -> Interceptor for the addMethod -> addMethod
2) sub -> Interceptor for the sub -> Interceptor for the subMethod -> subMethod

So, is possible, for example, in some interceptor at the fist invocation chain, 
invoke the subMethod instead of the addMethod, or return to the add method a 
combination of results of the addMethod and subMethod?

Thanks,

-- 
Douglas Siqueira Leite
Graduate student at University of Campinas (Unicamp), Brazil