Vincent Tietz

A metamodel for context-aware component-based mashup applications

Recently, mashups, i.e., composite web applications, have gained momentum in both the consumer and enterprise sector. However, they lack a structured development process which abstracts from specific platforms and enables a universal composition including the presentation layer. Moreover, support for context-awareness in such applications has been neglected so far. Yet, it becomes increasingly necessary due to the growing heterogeneity of users and devices. We address these issues by proposing an open, extensible metamodel for component-based mashup applications. It defines their control flow, layout, and adaptivity while building on lessons learned from traditional web application models. This metamodel forms the basis for a structured, model-driven development process entailing reusability and independence from specific composition platforms. We implemented the metamodel and successfully proved its practicability with a number of exemplary applications deployed on different platforms.

Task-Based recommendation of mashup components

Presentation-oriented mashup applications are usually developed by manual selection and assembly of pre-existent components. The latter are either described on a very technical, functional level, or using informal descriptors, such as tags, which bear certain ambiguities. With regard to the increasing number and complexity of available components, their discovery and integration has become a challenge for non-programmers. Therefore, we present a novel concept for the task-based recommendation of mashup components, which comprises a more natural, task-driven description of user requirements and a corresponding semantic matching algorithm for universal mashup components. By its realization and integration with an composition platform, we could prove the feasibility and sufficiency of our approach.

Towards task-based development of enterprise mashups

In order to align enterprise systems and business processes (BPs), models are used for specification and communication of business goals and activities. While model-based system integration is well elaborated for data and logic, the realization of human-involved activities is still a challenge. In this regard, enterprise mashups promise the quick and cost-effective solution to the development of composite applications representing reoccuring interactive, human-involved business cases. However, current mashup approaches and tools do not provide an integrated development method. To fill the gap between BP modeling and user interface (UI) mashups, we propose a model-driven development approach by considering mashup components as task-solving entities.

Attract me!: how could end-users identify interesting resources?

Recently, the interest in semantic web technologies increased in various domains, e.g., software engineering or biology. Since this technologies address the long tail of information domains with missing content types, the number of linked datasets will grow even more rapidly. Tech-savvy users and scientists benefit from this trend as they have the knowledge to created complex queries, and thus, to retrieve interesting subsets and answers. However, end-users have difficulties to understand the datas paradigm and need appropriate tool support to slice and dice the data to understandable parts or particular resources. In this paper, we propose a novel approach to enable end-users to browse huge semantic datasets, to detect, and to select interesting resources according to their specific tasks. Based on our evaluation results of two user studies using a web-based prototype we explain, which visualization and interaction techniques in combination with automatic filters are well-suited for novices.

Tool support for semantic task modeling

In the domain of Web applications, several model-based approaches have been introduced, supporting user-centered requirements engineering and thereon the identification of presentation elements and interaction techniques. Semantic application modeling and task decomposition provides promising results, especially for Web mashups. However, current tooling support lacks semantics-based and user-driven modeling facilities, making it unsuitable for matching algorithms and semantic mashup composition. This paper presents a novel concept for a task modeling tool, supporting ontology-based requirements specification of enterprise mashups. It smoothly integrates in a Web mashup development process. We show the feasibility of our approach with the help of a prototype that is evaluated by a small user study.

Modeling and Utilizing Quality Properties in the Development of Composite Web Mashups

Ubiquitous Web resources and their manifold combinability are causing app development with current Web mashup platforms to be a challenging task, especially for low-skilled Web users. Hence, mashup composition demands for expressing quality requirements to facilitate selection and customization processes. Existing quality metamodels only provide guidelines or abstract categories, but neglect mashup-specific measuring directives and machine-readable representations. Therefore, we present a tailored quality property metamodel for composite Web mashups. We show, how it supports different settings of mashup development and execution. Finally, we demonstrate the metamodels deployment in a mashup infrastructure and its utilization in different use cases.

Cloud-Entwicklungsmethoden: Überblick, Bewertung und Herausforderungen

ZusammenfassungGegenwärtig wird das Cloud-Computing für die dienstbasierte Nutzung skalierbarer Computerressourcen, wie z. B. Speicher, Rechenleistung oder Anwendungen, häufig diskutiert. Der Anbieter ist verantwortlich für die zuverlässige Bereitstellung, während der Konsument die Dienste nach Bedarf nutzt und vergütet. Für die Entwicklung von Cloud-Anwendungen stellen die Anbieter oft eigene Entwicklungsumgebungen bereit, die dazu tendieren, den Kunden früh im Entwicklungsprozess an sich zu binden. Dieser Beitrag untersucht die Entwicklungsmethoden bestehender Cloud-Angebote für geschäftsorientierte Webanwendungen und bewertet sie anhand der Anforderungen eines modernen Entwicklungsprozesses.