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Binding

Simple Story

Knowing that a paper is about to be picked up is not enough. You need to know which paper.

Binding is how that gets handed to the teacher. Without it you could only ever answer yes or no to "may this pupil pick up papers at all", never "may they pick up this one".

What it is​

Binding passes the context of the join point into the advice: the arguments, the target object, the signature of the intercepted member.

Binding is exactly what the architecture layer lacks. Static analysis is argument-insensitive: it sees that a file-opening method is reachable, not which path is passed. The aspect-oriented programming (AOP) layer has the actual argument at the moment of the call, which is why a policy can permit something.txt and deny secret.txt and have that distinction mean something at runtime.

It is why a narrow allowance stays narrow even though the static layer cannot represent it.

Further reading​