Using MDA in Web Software Architectures Santiago Meliá Cristina Cachero Jaime Gómez Universidad de Alicante Spain

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/2 Content Introduction Motivation Work Context & Goals. WebSA: Web Software Architecture. WebSA expressed with MDA. The view Model. Logical Architecture View in MDA. Generation strategy. Extension of the Architecture for MDA Models. Conclusions & Future Work

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/3 1. Introduction The new challenges posed by Internet Market imply: Development of more sophisticated Web Applications in a shorter period of time. Higher quality level to satisfy more demanding clients. The possibility to cover a vast diversity of web applications with different non functional requirements like number of clients, security, maintenance,etc.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/4 1. Introduction Work context: Up to now, Web methodologies (OO-H [Cachero03], UWE[Koch03], OOHDM, [Schwabe99],etc) have paid little attention to non functional requirements for web applications. Web generation techniques are only used to obtain code for a predefined architecture of web applications. Objectives: Integrate software architecture into Web Applications in order to cover the gap between web design and non functional requirements. Have the ability to generate code able to cover the vast diversity of web applications.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/5 2. Web Software Architecture A new proposal called WebSA (Web Software Architecture) which is based on two main aspects: The definition of specific software architecture models for Web (DSSA) to complement other UML proposals in the specification of Web Applications. The use of the MDA standard [OMG 2001] to formalize and describe such models.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/6 3. WebSA expressed with MDA [OMG2001] MDA defines an architecture for models and provides a set of guidelines for structuring specifications expressed as models. It defines concepts as View, Refinement, Abstract. WebSA splits the web software architecture description in several concurrent views as other authors do with UML [Krunchen95] [Hofmeister et all. 1999]. WebSA does this using also MDA and focusing on the web domain, which allows for a higher level of details in the specification process.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/7 3.1 The WebSA view model This view model represents briefly the reference model of WebSA.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/8 3.2 Logical architecture view in MDA The Logical Architecture defines the set of logical components (subsystems, modules and/or software components) and the relationships between them. The WebSA logical architecture is subdivided in three models: Subsystem Model: determines which are the subsystems that make up our application and the best distribution in layers of our system. Web Component Configuration Model: provides an ontology of web abstract components and connectors that are particular to the web domain. Web Component Integration Model: connects the functional and the architectural views under a common set of concrete components, modules and connectors.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/9 3.2 Logical architecture view in MDA The three architectural models are Independent from the Platform. Integration Model is defined at a level of abstraction similar to that of the EDOC profile[OMG 2002]. WebSA is capable of automatically providing different mappings platforms such as EJB, CORBA or.NET. Subsystem Model > D1 > CWD1 {card=1} > M1 {card=*} > VWD1 {card =1} > SWD1 {card=*} > n > 1..n > 1..n > n > Web Component Configuration Model Functional Viewpoint > Web Component Integration Model CCW1 serviceRequest() navigationRequest() > Client newClient() deleteClient() checkClient() getClient() (from ModuleModel1) > Cart newCart() addItem() deleteItem() showAllItems() generateOrder() (from ModuleModel1) > Order newOrder() (from ModuleModel1) > generateOrder > checkClient > newCart > newOrder >

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/ Logical architecture view in MDA Possibility to classify the Web Integration Model as PIMs in the context of MDA. Integration Model is defined at a level of abstraction similar to that of the EDOC profile[OMG 2002].

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/11 > Web Integration Component Model CCW1 serviceRequest() navigationRequest() > Client newClient() deleteClient() checkClient() getClient() (from ModuleModel1) > Cart newCart() addItem() deleteItem() showAllItems() generateOrder() (from ModuleModel1) > Order newOrder() (from ModuleModel1) > generateOrder > checkClient > newCart > newOrder > XML Interface Template-Code Generator J2EE.NETCORBA WebSA Generation Strategy Standard PSM

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/12 4. The Problem with Traditional MDA MDA, [OMG 2001] when referring to quality attributes says “it is desirable to support and integrate such features in the modeled applications”. Such integration can only be achieved, as stated in [Bass et al. 2000], by specifying the software architecture system. The subsystem model and the web component configuration model cannot be integrated in the traditional views of MDA because they are independent from the problem domain, and are exclusively influenced by the non functional requirements or quality attributes.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/13 4. Extension of the architecture for MDA Models Extended architecture provides: A more rigorous mapping between the analysis phase and the design phase. A better quality of the generated code, because it allows the definition of a generation mechanism where both the functional and the architectural parts are combined Computation Independent Business Model Platform Independent Component View Platform Specific TRADITIONAL ARCHITECTURE FOR MDA MODELS Incomplete Analysis-Design Mapping Computation Independent Business Model Platform Independent Component View Platform Specific Software Architectural Model EXTENDED ARCHITECTURE FOR MDA MODELS Complete (Analisys+Architecture)- Design mapping

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/14 Conclusions & Future Works Conclusions We have presented a new proposal called WebSA for the development of web applications. Its aim is to extend the traditional MDA so as to capture the non functional requirements. We have proposed a code generation approach for mapping a WebSA specification to an implementation. Future Works We are in the process of defining the UML profile of WebSA. We are going to extend the VisualWADE CASE Tool to support this approach. We intend to generate an XML specification to feed template-code generators.

Santiago Meliá, Cristina Cachero & Jaime GomezOOPSLA´03/15 Thanks for your attention!! Questions? For further comments...