StaBL - State Based Language for Specification of Web Applications

Context and motivation: Usage of Formal Specification languages is scarce in web application development as compared to safety critical/hardware systems. Question/problem: An apt formal specification language should provide the following features: Firstly, it should have well-defined semantics, so that specifications written in it can not be inherently ambiguous. Secondly, it should have tool support for automatic detection of specification bugs. Additionally, for domains like web development, it is important that specification formalisms build over familiar notations, as the benefits of learning highly mathematical notations in such domains are perceived to be low. Principal ideas/results: This work presents a State Based Language inspired by Statecharts called StaBL for specification of web applications, and how StaBL can be used for writing such specifications. We also present modifications to the language w.r.t Statechart which facilitate writing modular and scalable specification. Contribution: In particular, we present the feature of locally scoped variables with inter-state data-flow. We summarise our experience of developing specifications with StaBL, which shows that StaBL specifications, on the one hand, are able to capture most essential elements of the functional aspects of a web application while foregoing much of the verbosity of a regular programming language.