Architectural Style for Rich Web-Based Applications

The complexity in software systems encompasses the difficulties in understanding their formalism. The Rich Web-based Applications consist of different types of components, integrated in diverse ways, which makes the understanding of the components and their configurations difficult. The complexity of Rich Web-based applications, it would be argued in this work, is related to the lack of a sound abstract architectural foundation within, which it could be understood. Furthermore, the development of the Rich Web-based application systems is incorporated with numerous Techniques and Technologies, which introduce new layer of complexity into the development activities. Solutions provided by the previous research exhibit Technique/Technology dependencies, thus they do not provide abstract realization; and also they incorporate high learning curves and limited adoption.

We argue that by using a more principled architectural solution, which can realize the abstract formalism of Rich Web-based Applications, the complexity can be overcome. Since a software architecture directly assists the development, a sound architectural formalism would ease the development activities. Based on this argument, this study introduces a hybrid architectural style – named “Rich Web-based Application Architectural style” (RiWAArch style in short) – for reducing the complexity of Rich Web-based Applications by increasing the realization. RiWAArch style is abstract thus independent from Techniques and Technologies, and incorporates a lower learning curve, providing better adoption in wider environments. It was hypothesized that 1) common characteristics and essential abstract features of RiWAs can be identified, regardless of the development techniques and technologies, 2) the abstract rationale behind the architecture of RiWAs can be described by a TTs independent architectural style, consisting of a set of constraints applied to the elements within the RiWAs, explaining the configuration of the elements, and 3) constraints can be added to the basic model of the Web-based systems, which is the Client-Server style, to derive a new hybrid style, which offers desired architectural properties of Rich Web-based Applications. Equal concentration is given to define the Rich Web-based Applications and related concepts like Delta-Communication; and to provide classifications and taxonomies for the Techniques and Technologies used in the development of the Rich Web-based Applications, towards proper decision making in selecting Techniques and Technologies for the components of the RiWAArch style.

The findings from a series of experiments were utilized to identify and specify some abstract common characteristics and essential features of Rich Web-based Applications, and some features to be expected from RiWAArch style, in order to deliver the identified characteristics and features. Based on these expected features, a set of requirements to be satisfied by the Abstract iv RiWAArch style are set. The functional requirements were utilized to form the constraints for deriving the RiWAArch style. The non-functional requirements were consumed to form the architectural properties to be induced by the derivation. Then the derivation was done by applying the constraints one by one, starting from the Null style. Finally a derivation tree was formnulated and utilized for the evaluation of the derived style. The initermediate styles and the ultimate RiWAArch style were evaluated agaist the candidate styles based on the properties induced by the constraints, aligning to the derivation tree.

The dissertation concludes that the RiWAArch style satisfies the requirements adequately. RiWAArch style separates processing components exploiting Client-Server partitioning and MVC based modularizing, in an abstract and extensible manner; providing higher Simplicity, Performance, Scalability, Portability, and Adoptability, compared to the available MVC based solutions. RiWAArch style incorporates Delta-Communication, clearly separating from non-Delta-Communication, by introducing a comprehensive Delta-Communication connector, increasing the Simplicity, Modifiability, Reusability, and Visibility. The evaluation of the research shows that the RiWAArch style delivers higher preservation of the required architectural properties compared to the available architectural styles for RiWAs.

The results of this research can be followed by a process of introducing a framework and development tool for rapid development of Rich Web-based Applications, based on the RiWAArch style.