Towards a Generic Model for Web Services Mashups using the Spreadsheet Paradigm

The proliferation of Web services and online resources enabled a self-service application development method, namely "mashup", that combines together existing data and services to create ad-hoc, idiosyncratic applications. Typically, mashup tools possess user-friendly interfaces with simple user interaction mechanisms that enable individuals rapidly build applications without any in-depth technical skill requirements. To realise the full benefit of mashups, there is a need to support the paradigm through an established platform that has a large user base.Spreadsheets are popular productivity tools and are proven to be useful in manipulation, analysis, visualisation, and reporting of data. They have been also tagged as the most successful end-user development environment with millions of users. In this dissertation, we address the issue of providing a generic mashup development framework, through an application of the spreadsheet paradigm. We propose a novel framework, named MashSheet, which allows users to create mashup applications using spreadsheet-like formulas.The key innovation of MashSheet is a collection of operators that supports coordinating Web services, manipulating and visualising data created by the services. MashSheet applications are incrementally built and data in each intermediary step is only visualised when needed. It makes the mashup applications concise and easy to follow, as well as keeping their computation logic separate from presentation.Although the issue of reusing already-built applications has been previously studied in mashups and other spreadsheet research areas, its potential has not been fully realised in the state-of-the-art spreadsheet-based mashup tools. To enable users to reuse existing mashup applications in MashSheet, we propose a reuse model which consists of mashup templates and a template repository. The design of mashup templates in MashSheet allows the users to stay in the spreadsheet paradigm they are familiar with when applying the reuse model.The approach proposed in this dissertation have been implemented in a prototype and validated via experiments in real-world scenarios. We also conduct studies of the framework to evaluate its usability and expressiveness. The result shows that (i) MashSheet is expressive and flexible to support numerous application scenarios; and (ii) MashSheet reduces the application development time compared to one of the state-of-the-art spreadsheet-based mashup tools