Abstract:
The thesis demonstrates that visual approaches to modelling event-based systems are more effective
than traditional textual scripts and code. We have both investigated existing approaches and
developed new techniques for visual event-based system integration. We have used domain-specific
visual languages with different high-level visual metaphors to specify event-handling support and
provide backend processing tool support for both event integration specification and visualisation of
event propagation.
We have developed three different visual metaphors for event-based system specification. The first,
ViTABaL-WS, uses the Tool Abstraction (TA) metaphor to support specification of web services
composition via higher level data and control flows and generation of BPEL4WS code. The second,
Kaitiaki, uses an Event-Query-Filter-Action (EQFA) metaphor to allow visual primitives
composition and java code generation for diagramming tool event handlers. The third, MaramaTatau,
uses a spreadsheet-like metaphor to construct metamodel formulae visually to specify structural
dependencies and constraints to be realised at runtime.
We have generalised from these three visual event-driven system metaphors to develop a new,
generic visual event handling metaphor. From this we have built a novel multi-paradigm hybrid
metamodelling environment for specifying generic event-based system behaviours.