Integrating OCL and Textual Modelling Languages

In the past years, many OCL tools achieved a transition of OCL from a language meant to constrain UML models to a universal constraint language applied to various modelling and metamodelling languages. However, OCL users still experience a discrepancy between the now highly extensible parsing and evaluation backend of OCL tools and the lack of appropriate frontend tooling like advanced OCL editors that adapt to the different application scenarios. We argue that this has to be addressed both at a technical and methodological level. Therefore, this paper provides an overview of the technical foundations to provide an integrated OCL tooling frontend and backend for arbitrary textual modelling languages and contributes a stepwise process for such an integration. We distinguish two kinds of integration: external definition of OCL constraints and embedded definition of OCL constraints. Due to the textual notation of OCL the second kind provides particularly deep integration with textual modelling languages. We apply our approach in two case studies and discuss the benefits and limitations of the approach in general and both integration kinds in particular.