OCL for rich domain models implementation: An incremental aspect based solution

Object Constraint Language (OCL) can be used to express domain model constraints. Those related to a single object are easy to implement. However, when a constraint depends on the state of more than one object (domain and class constraints) the problem turns much more complicated. Developers must deal with several difficulties: how to write the invariant check, when to execute the constraint verification, over what objects and what to do in case of a constraint violation. Things are harder if we add feasible performance as requirement. We propose a tool that combines incremental OCL processing, with translation into aspect code and execution inside an atomicity execution context. The output is aspect code, ready to be integrated with business code that checks all the invariants efficiently at the end of the atomic operation.