In this thesis, we present an abstract meta-model for model driven development of web applications targeting multiple platforms. We review the existing technologies and the related work in order to obtain a list of requirements for such an abstract model. The abstract model is built by extending an existing UML-based model for web applications. We demonstrate that it is possible to map this abstract model to more than one specific development platform by providing transformations for these mappings. We also lay out the general outline of a model-driven process based on the proposed abstract model. The abstract model and the model-driven process are supported by a set of tools, case studies and a visual modeling notation. Model-driven techniques have been used in the area of web development to a great extent. Most of the existing approaches are tuned toward specific platforms or develop only certain parts of web applications. These approaches generally use meta-models adapted to their targeted platforms. In order to flexibly target multiple platforms, the level of abstraction of the meta-model must be raised. Such a meta-model must allow the description of relevant features of web applications independently from the specificities of specific platforms. Additionally, transformations mapping from abstract to specific web descriptions must be expressible in a flexible way. In this thesis, we propose such an abstract meta-model. Mappings that transform abstract models to specific platforms are also presented. Different benefits can be foreseen from this approach. By relieving developers from low-level platform-specific related design, the approach has the potential to shift the development task to issues related to business needs. Another benefit is shortened development time. This could help web developers to overcome the problem of schedule delays, which is recognized as one of the top five most-cited problems with large-scale web systems. The approach is specifically suitable for information-intensive web-based systems. These applications typically involve large data stores accessed through a web interface. A distinctive aspect of this approach is its use of a specification of the data mapping as part of its high-level input. More importantly, the common features required to process data and communicate data objects between different layers and components are targeted.

In this thesis, we present an abstract meta-model for model driven development of web applications targeting multiple platforms. We review the existing technologies and the related work in order to obtain a list of requirements for such an abstract model. The abstract model is built by extending an existing UML-based model for web applications. We demonstrate that it is possible to map this abstract model to more than one specific development platform by providing transformations for these mappings. We also lay out the general outline of a model-driven process based on the proposed abstract model. The abstract model and the model-driven process are supported by a set of tools, case studies and a visual modeling notation. Model-driven techniques have been used in the area of web development to a great extent. Most of the existing approaches are tuned toward specific platforms or develop only certain parts of web applications. These approaches generally use meta-models adapted to their targeted platforms. In order to flexibly target multiple platforms, the level of abstraction of the meta-model must be raised. Such a meta-model must allow the description of relevant features of web applications independently from the specificities of specific platforms. Additionally, transformations mapping from abstract to specific web descriptions must be expressible in a flexible way. In this thesis, we propose such an abstract meta-model. Mappings that transform abstract models to specific platforms are also presented. Different benefits can be foreseen from this approach. By relieving developers from low-level platform-specific related design, the approach has the potential to shift the development task to issues related to business needs. Another benefit is shortened development time. This could help web developers to overcome the problem of schedule delays, which is recognized as one of the top five most-cited problems with large-scale web systems. The approach is specifically suitable for information-intensive web-based systems. These applications typically involve large data stores accessed through a web interface. A distinctive aspect of this approach is its use of a specification of the data mapping as part of its high-level input. More importantly, the common features required to process data and communicate data objects between different layers and components are targeted.

In this thesis, we present an abstract meta-model for model driven development of web applications targeting multiple platforms. We review the existing technologies and the related work in order to obtain a list of requirements for such an abstract model. The abstract model is built by extending an existing UML-based model for web applications. We demonstrate that it is possible to map this abstract model to more than one specific development platform by providing transformations for these mappings. We also lay out the general outline of a model-driven process based on the proposed abstract model. The abstract model and the model-driven process are supported by a set of tools, case studies and a visual modeling notation. Model-driven techniques have been used in the area of web development to a great extent. Most of the existing approaches are tuned toward specific platforms or develop only certain parts of web applications. These approaches generally use meta-models adapted to their targeted platforms. In order to flexibly target multiple platforms, the level of abstraction of the meta-model must be raised. Such a meta-model must allow the description of relevant features of web applications independently from the specificities of specific platforms. Additionally, transformations mapping from abstract to specific web descriptions must be expressible in a flexible way. In this thesis, we propose such an abstract meta-model. Mappings that transform abstract models to specific platforms are also presented. Different benefits can be foreseen from this approach. By relieving developers from low-level platform-specific related design, the approach has the potential to shift the development task to issues related to business needs. Another benefit is shortened development time. This could help web developers to overcome the problem of schedule delays, which is recognized as one of the top five most-cited problems with large-scale web systems. The approach is specifically suitable for information-intensive web-based systems. These applications typically involve large data stores accessed through a web interface. A distinctive aspect of this approach is its use of a specification of the data mapping as part of its high-level input. More importantly, the common features required to process data and communicate data objects between different layers and components are targeted.

While the separation of presentation and application logic is widely practiced in web-based applications today, many do not cleanly separate application and dialog control logic, which leads to inflexible implementations especially when multiple presentation channels shall be served by the same application logic. We therefore present a notation for specifying the complete dialog flow of an application separately from the application logic and show how to construct a formal metamodel for it using the OMG’s Meta-Object Facility (MOF). This allows the validation of dialog flow models, as well as the generation of machine-readable dialog flow specifications from graphical models.

There is a growing amount of digital information available from Open-Data initiatives, Internet-of-Things technologies, and web APIs in general. At the same time, an increasing amount of technology in our lives is creating a desire to take advantage of the generated data for personal or professional interests. Building interactive applications that would address this desire is challenging since it requires advanced engineering skills that are normally reserved for professional software developers. However, more and more interactive applications are prototyped outside of enterprise environments, in more opportunistic settings. For example, knowledge workers apply end-user development techniques to solve their tasks, or groups of friends get together for a weekend hackathon in the hope of becoming the next big startup. This thesis focuses on how to design prototyping tools that support opportunistic development of interactive applications that take advantage of the growing amount of available data. In particular, the goal of this thesis is to understand what are the current challenges of prototyping with data and to identify important qualities of tools addressing these challenges. To accomplish this, declarative development tools were explored, while keeping focus on what data and interaction the application should afford rather than on how they should be implemented (programmed). The work presented in this thesis was carried out as an iterative process which started with a design exploration of Model-based UI Development, followed by observations of prototyping practices through a series of hackathon events and an iterative design of Endev – a prototyping tool for data-driven web applications. Formative evaluations of Endev were conducted with programmers and interaction designers.  The main results of this thesis are the identified challenges for prototyping with data and the key qualities required of prototyping tools that aim to address these challenges. The identified key qualities that lower the threshold for prototyping with data are: declarative prototyping, familiar and setup-free environment, and support tools. Qualities that raise the ceiling for what can be prototyped are: support for heterogeneous data and for advanced look and feel. / Mer och mer digital information görs tillgänglig på olika sätt, t.ex. via öppna data-initiativ, Sakernas internet och API:er. Med en ökande teknikanvändning så skapas även ett intresse för att använda denna data i olika sammanhang, både privat och professionellt. Att bygga interaktiva applikationer som adresserar dessa intressen är en utmaning då det kräver avancerade ingenjörskunskaper, vilket man vanligtvis endast hittar hos professionella programmerare. Sam­tidigt byggs allt fler interaktiva applikationer utanför företagsmiljöer, i mer opportunistiska sammanhang. Detta kan till exempel vara kunskapsarbetare som använder sig av s.k. anveckling (eng. end-user development) för att lösa en uppgift, eller kompisar som träffas en helg för att hålla ett hackaton med hopp om att bli nästa framgångsrika startup-företag. Den här avhandlingen fokuserar på hur prototypverktyg kan utformas för att stödja utveckling av interaktiva applikationer i sådana opportunistiska sammanhang, som utnyttjar den ökande mängden av tillgänglig data. Målet med arbetet som presenteras i den här avhandlingen har varit att förstå utmaningarna som det innebär att använda data i prototyparbete och att identifiera viktiga kvalitéer för de verktyg som ska kunna hantera detta. För att uppnå detta mål har verktyg för deklarativ programmering utforskats med ett fokus kring vilken data och interaktion en applikationen ska erbjuda snarare än hur den ska implementeras. Arbetet som presenteras i den här avhandlingen har genomförts som en iterativ process, med en startpunkt i en utforskning av modellbaserad gränssnittsutveckling, vilket sedan följdes av observationer av prototyparbete i praktiken genom en serie hackathon och en iterativ design av Endev, som är ett prototypverktyg för att skapa datadrivna webbapplikationer. Formativa utvärderingar av Endev har utförts med programmerare och interaktionsdesigners. De viktigaste resultaten av den här avhandlingen är de utmaningar som har identifierats kring hur man skapar prototyper och de kvalitéer som krävs av prototypverktyg som ska adressera dessa utmaningar. De identifierade kvalitéerna som sänker trösklarna för att inkludera data i prototyper är: deklarativt prototyparbete, välbekanta och installationsfria miljöer, och supportverktyg. Kvalitéer som höjer taket för vad som kan göras i en prototyp är: stöd för olika typer av data och för avancerad “look and feel”.

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Ein zentraler Vorteil des Webs gegenüber herkömmlichen Anwendungsplattformen stellt sein großes Potential dar, Aufgaben über Organisationsgrenzen hinweg zu unterstützen. Derzeit lassen sich Tendenzen zu einer Klasse von föderativen Web-Anwendungen beobachten, die dieses Potential verstärkt ausschöpfen. Eine besondere Herausforderung bei ihrer Entwicklung ergibt sich durch die Ausrichtung der Zugangskontrolle auf zugreifende Benutzer, deren Identitäten von Partnerorganisationen verwaltet werden. Die Arbeit erweitert den Stand der Technik im Bereich Web Engineering um Werkzeuge, Modelle, Methoden und Prozesse zum gezielten Unterstützen der Evolution föderativer Systeme. Sie umfasst einen Katalog aus Entwurfsbausteinen für föderative Infrastrukturen, eine Modellierungssprache zur Planung der föderativen Architektur sowie eine Methode zur Integration föderativ geschützter Informationsräume in Web-Anwendungen. / A central advantage of the Web over traditional application plattforms lies in its great potential for supporting tasks beyond organizational boundaries. Presently, a trend towards a new class of federated Web applications can be observed that exploit this potential to a high degree. The development of such applications is particularly challenged by the need for controlling accesses of users whose identities are managed by partner organizations. This work extends the state of the art in the area of Web Engineering with tools, models, methods and processes for supporting the evolution of federated systems. It comprises a catalogue of design building blocks for federated infrastructures, a modeling language for planning federated architectures as well as a method for integrating information spaces of applications that are subject to federated access control.

Made available in DSpace on 2014-06-12T15:56:54Z (GMT). No. of bitstreams: 2 arquivo3088_1.pdf: 3675787 bytes, checksum: 37a4c170a186d859bd4fc51979cf5556 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Modelos oferecem abstrações de um sistema que possibilitam aos engenheiros raciocinarem sobre o sistema se focando apenas nos aspectos relevantes, ignorando detalhes que não são relevantes. UML se tornou um padrão de fato para análise e projeto de sistemas, mas possui algumas limitações óbvias: (1) o conjunto de elementos é muito heterogêneo e grande, e (2) o suporte de ferramentas não é satisfatório. Faz-se necessário um sistema de regras que governem o processo de análise e projeto; UML é geral demais. Desenvolvido pela UFPE em conjunto com a Universidade de Mannheim, o objetivo do método KobrA2 é resolver essas limitações através da incorporação de visões especiais de layout, navegação e comportamento de componentes de interface gráfica do usuário (GUI), e pela introdução do conceito de engenharia de software ortográfica, na qual a construção de Modelos Independentes de Plataforma (PIM) para cada componente de software é realizado em pequenas partes através da construção ortogonal de visões específicas para cada preocupação do componente. Estas visões são então integradas dentro de um Modelo Unificado (SUM) que por sua vez verifica a conformidade com os artefatos do meta-modelo de KobrA2. Para gerar ganhos de produtividade, esta integração e verificação deve ser automaticamente implementada através da transformação de modelos interna a uma ferramenta CASE. Consequentemente, para ter sucesso, KobrA2 precisa de uma ferramenta que dê suporte ao seu processo de engenharia de sistemas. Esta dissertação de mestrado é parte do projeto WAKAME (Wep App KobrA2 Modeling Environment) que tem por objetivo a construção desta ferramenta CASE. Além de ser a primeira ferramenta CASE dirigida por processo e que dá suporte a um ambiente OO, ortográfico, dirigido por modelos e baseado em componentes, para engenharia de aplicações, incluindo a construção de GUI PIMs, WAKAME também procura inovar por ser (a) distribuída em uma plataforma de cloud computing e acessível universalmente através de qualquer navegador Web, (b) ser de muito fácil aprendizagem graças a sua GUI minimalista, com poucos ícones, no estilo do Google, e (c) de uso eficiente graças ao seu cliente projetado para ser leve e com pouco uso de memória e que forneça um esquema de navegação multidimensional, ortográfico e independente de plataforma, entre visões de baixa granularidade, específica a preocupações, e locais, de um componente. Dentro do projeto WAKAME, esta dissertação de mestrado investiga três principais questões em aberto. A primeira é o projeto de KWAF (KobrA2 Web App Framework), um modelo independente de plataformas de um ambiente OO genérico para ser instanciado para projetos específicos de aplicações Web. A segunda é o PIM detalhado de WAKAME como um exemplo de instanciação de KWAF. A terceira é a implementação e avaliação de componentes de GUI, cobrindo (a) as visões estruturais de componentes KobrA2 que minimamente estendem um subconjunto mínimo de diagramas de classes UML e restrições estruturais de OCL, e (b) as visões operacionais de componentes KobrA2 que consistem de precondições, pós-condições e restrições body de OCL sobre operações UML. As principais contribuições desta dissertação são: (a) o projeto de KWAF, o primeiro estudo de caso para avaliação do processo KobrA2 para aplicações Web ricas com gráficos 2D, (b) o projeto de alto nível do WAKAME como estudo de caso para avaliação de KWAF, (c) a implementação de um cliente Web fácil de usar e eficiente para o projeto ortográfico de PIMs de composição de componentes KobrA2, e (d) a integração e teste deste cliente GUI com os serviços baseados em nuvem computacional de WAKAME para integração, verificação e persistência de visões PIM dentro do SUM

Para o desenvolvimento de aplicações Web de qualidade, o uso de uma abordagem sistemática e disciplinada é essencial, dado o crescente aumento do uso e da complexidade de tais aplicações. Nesse cenário, a Engenharia de Aplicações Web, ou simplesmente Engenharia Web, torna-se uma atividade mandatória. A Engenharia Web não é uma transcrição exata da Engenharia de Software, pois considera caracterí?sticas inerentes às aplicações Web como, por exemplo, multiplicidade do perfil de usuários e uso de multimídia. A Engenharia Web é apoiada por ferramentas, técnicas e métodos. A escolha desses elementos para um domínio de aplicação pode tornar-se uma tarefa difícil para desenvolvedores e demais interessados e é fundamental para o desenvolvimento efetivo de aplicações Web. Neste trabalho, é apresentado uma proposta de avaliação de métodos de desenvolvimento de aplicações Web. Essa proposta partiu de um conjunto de métodos selecionados por meio de trabalhos comparativos anteriores disponíveis na literatura e do levantamento de suas principais características, após estudo de caso que consistiu em modelar uma mesma aplicação (um portal Web) com os diferentes métodos selecionados. A cada característica associaram-se pesos, refletindo sua relevância a domínios especifícos, e valores refletindo seu grau de apoio a um método. Como resultado, obteve-se um arcabouço - conjunto de guidelines - para avaliar e/ou especificar métodos de desenvolvimento de aplicações Web. Esse arcabouço foi aplicado ao conjunto de métodos selecionados do estudo de caso e foram obtidas evidências da efetividade do arcabouço proposto / For the development of high quality Web applications, the use of a systematic and disciplined approach is essential, given the increasing use and complexity of such applications. In this scenario, the Web Applications Engineering, or simply Web Engineering, becomes a mandatory activity. The Web Engineering is not an accurate transcription of the Software Engineering. Besides incorporating its rules and lines of direction, the Web Engineering also considers inherent characteristics of Web applications such as user profiles multiplicity and multimedia resources. For the Web applications development process, the Web Engineering is supported by tools, techniques and methods. Among them, choosing appropriate elements for a given application domain may represent a challenge for interested developers. This work aims at supporting such choices through a proposal of an evaluation of current development methods for Web Applications. The proposed framework started from a set of well-known development methods found in the literature from which the main characteristics were identified by a case study consisted in modelling the same Web application by different methods. For each characteristic, weights have being associated, reflecting its relevance for specific domains, and values reflecting its degree of support to a method. As result, a framework is estabilished - set of guidelines - to evaluate and/or to specify methods of development of Web applications. This framework was applied to the set of selected methods of the case study and evidences have been provided effectiveness of the proposed framework

Com o aumento do uso e da complexidade de sistemas web, o desenvolvimento de tais sistemas com qualidade exige a adoção de uma abordagem sistemática e bem definida. Assim, a engenharia web é uma disciplina essencial que considera, além de características da engenharia de software, fatores inerentes aos sistemas web, como a multiplicidade de perfis de usuários. A engenharia web é apoiada por processos, métodos, técnicas e ferramentas que são elementos fundamentais para o desenvolvimento de sistemas web, os quais devem ser adequados para fornecer suporte às ações inerentes ao projeto e à implementação. Esses elementos devem ser selecionados, combinados e tecnicamente implementados de modo a produzir um sistema web acessível e usável. Nesta tese é proposto um processo de desenvolvimento que possui fases gerais bem definidas para a inserção de requisitos de acessibilidade e usabilidade no desenvolvimento de sistemas web, garantindo o seu uso pela maioria das pessoas e facilitando seus meios de acesso. Um estudo de caso foi realizado para verificar a efetividade da aplicação do processo formalizado, o qual possibilitou o desenvolvimento de um sistema acadêmico de agendamento de bancas. Considerando-se a dificuldade prática de avaliar diretamente o processo, foram realizados um experimento controlado e um estudo de viabilidade comparando o sistema acadêmico desenvolvido com outro sistema de mesmo propósito e funcionalidades, mas desenvolvido de maneira ad-hoc. Por meio das avaliações realizadas nos dois sistemas de agendamento de bancas, indiretamente avaliou-se o processo formalizado e foram encontrados fortes indícios sobre a efetividade do processo proposto. Adicionalmente, foi criado um instrumento de medição objetivo e quantitativo das características de acessibilidade e usabilidade de um sistema web. Foi também criado um método para avaliar, comparar e melhorar a acessibilidade e a usabilidade de sistemas web existentes. Tanto o instrumento de medição quanto o método de avaliação podem ser aplicados, independentemente, a qualquer sistema web. / With the increasing use and complexity of web systems, the development of such systems with quality demands the adoption of a systematic and well-defined approach. Thus, web engineering is an essential discipline that considers, in addition to characteristics of software engineering, factors inherent to web systems, such as the multiplicity of the users profiles. Web engineering is supported by engineering processes, methods, techniques and tools that are fundamental elements to the development of web systems, which must be adequate to support the activities of design and implementation. These elements should be selected, combined and technically implemented to produce an accessible and usable web system. This thesis proposes a development process with welldefined phases for including requirements of accessibility and usability in the development of web systems, enabling their use by most people, facilitating their means of access and foremost. A case study was conducted to verify the effectiveness of applying the process proposed and with this objective, a system to schedule thesis and dissertation presentations was developed. Considering the practical difficulty of directly measuring the proposed process, a controlled experiment and a feasibility study was conducted to compare the academic system developed with a legacy system with the same purpose and functionality but developed using an ad-hoc process. Considering the evaluation of both systems, the development process was indirectly evaluated and evidences related to its effectiveness have been identified. Additionally, an objective and quantitative method for measuring accessibility and usability of web systems was created. Finally, it was also created a method to evaluate, compare and improve the accessibility and usability of existing web systems, which was used to evaluate the system developed using the proposed process. Both the measuring instrument and the evaluation method can be applied, independently, to any web system