AOM Core Discussion

UML/Models 2005Workshop 7: “Aspect Oriented Modeling”

Jörn Guy Süß,Research Officer

05/05/23

AOM Core

What is an aspect?

You don not really know what aspects do

• “Solves one problem, but in another situation creates craps”

What if you have model with 200+ classes

Trivial examples...

• Logging standard example – yawn…• Easily scalable for a large application• Real program models

– Not available– Functional crosscuting concerns hard to find– Different granularities you can look at aspects

Works in the small only

• Conflicting aspects– “Would not like to log confidential information”– Composition is problematic because of interrelations

between aspects easy to break the structure by removing aspect

– Analyse and verify agasint requirements• Impacts on other aspects

– Order of aspects

Common Core Metamodel needed to scale

• Something as base to compare different models• Should UML be base notation or something more simpler?

– UML is missing possibilities to express relationships between the models– One needs AML– Unified type space to have one tool for UML and aspects– UML ->CWM; CWM -> UML– Class based models should be base

• MOF is just class diagrams– You draw your class diagram– Generate your stuff– Glue GUI on top of generated– Allows to define structure, signatures of operations

• No way to specify how to execute it• Methods, and then text for what methods actually do

Assembly process of aspects required

• Takes care of fact that we are not using the same definition of aspect

• Integration of approaches wont work as people wont agree what aspect is– Not the problem different terminology but lack of catalogue

• For reasons of traceability– People wont useone megalanguage

• Reuse– So far case studies dont show reuse as you need more– Need to educate students from very first days– Root commonality required

• For example benefits of design patters– Doest happen on the abstract, metamodel required

Tools

Tool vendors lock you in.

• Need to get stuff out of modelling tool and do it externally

• Hard to extend tools

Work with single model at a time

• Need to look at aspect and primary model at the same time. Relationships between models required.

• Lot of mental work still needed

Tools for defining model transformations exist

• Tefkat – The engine formerly known as Tarzan(a DSTC eclipse plugin)

• For example from class model to ERM • Target model as the view of the source model• Those things have very little publicity

What decisions are human decisions and where can you start automatic choices?

Restrain the Aspect?

Components vs. Aspects

• Components did promise"Buy your facility to have concern X managed“ Failed

• Will Aspects deliver?• Yes! Aspects are very flexible• No! Aspects are so flexible as too be useless in

application

The Two sides "(Gregor Kiczales)

• Yes!– Teaching students– Distributing work– Runtime Properties, NFPs

• No!What happens "when tomorrow comes

Why AOM is great! (for industry!)