Reactive behavior in object-oriented applications: an analysis and a research roadmap

Reactive applications are difficult to implement. Traditional solutions based on event systems and the Observer pattern have a number of inconveniences, but programmers bear them in return for the benefits of OO design. On the other hand, reactive approaches based on automatic updates of dependencies - like functional reactive programming and dataflow languages - provide undoubted advantages but do not fit well with mutable objects. In this paper, we provide a research roadmap to overcome the limitations of the current approaches and to support reactive applications in the OO setting. To establish a solid background for our investigation, we propose a conceptual framework to model the design space of reactive applications and we study the flaws of the existing solutions. Then we highlight how reactive languages have the potential to address those issues and we formulate our research plan.