AOP use cases

[John Roth]

"Peter Hansen" <peter at engcorp.com> wrote in message
news:0pydnSB4WYuieuLdRVn-hQ at powergate.ca...
> Will Stuyvesant wrote:
>
> > What are good usage examples?
>
> I would be very interested to hear some real-world and real useful
> use cases for AOP as well.  So far, the logging example seems to
> be put forth so often that I'm starting to suspect that's the
> *only* "useful" thing people are doing with it. :-)
>
>  From direct personal experience, could some AOP folks please
> point out some compelling use cases so that the doubting
> Thomases (and Wills, and Peters) can better understand and
> accept the idea of AOP as being more than just a few fringe
> cases?
>
> (The logging one actually annoys me: the only time I've ever
> wanted such logging was when debugging very complicated problems,
> and since switching to TDD I have never encountered anything
> that even remotely made me consider writing such logging wrappers
> again.)
>
> -Peter

I suspect you're not going to get any really compelling ones.
The reason I say this is a lot of experience I had about 30
years ago, when I was supporting an installation with IBM
mainframes, using MFT and MVT (the predecessors to MVS.)
One of my favorite methods of installing patches and modifications
was to insert code in the call paths between modules, using
patches and link editor gyrations.

Why? Because I couldn't get the source code to change it,
and even if I could have done so, changing it would have
exposed me to horrendous integration problems with
upgrades (something I had to learn the hard way.)

When you're supporting a monolithic proprietary application,
sometimes you have to do what you have to do, but today
the entire idea simply smells of a high-tech way to do
ad-hoc patching where a really well designed application
would not need it (and I don't really care if the design is
up front or emergent.)

John Roth