XCML: Providing Context-Aware Language Extensions for the Specification of Multi-Device Web Applications
World Wide Web 15(4): pp. 447-481 (2012)
There is a vast body of research dealing with the development of context-aware web applications that can adapt to... more There is a vast body of research dealing with the development of context-aware web applications that can adapt to different user, platform and device contexts. However, the range and growing diversity of new devices poses two significant problems to existing approaches. First, many techniques require a number of additional design processes and modelling steps before applications can be adapted. Second, the new generation of platforms and technologies underlying these devices as well as upcoming web standards HTML5 and CSS3 have partly changed the way in which web applications are implemented nowadays and often limit the way in which they can be adapted. In this paper, we present XCML as one example of a domain-specific language that tightly integrates context-aware concepts and adaptivity mechanisms to support developers in the specification and implementation of multi-channel web applications. In contrast to most existing approaches, the objective is to use a more lightweight approach to adaptation that can dynamically evolve and support new requirements as they emerge. Our solution builds on versioning principles in combination with a context matching process based on a declaration of context-dependent variants of content, navigation and presentation in terms of context expressions at different levels of granularity that are specific to the application. To support this, a formally defined context algebra is used to parse and resolve the context expressions at compile-time and to determine the best-matching variants with respect to the client context at run-time. We present the language concepts and a possible execution environment together with context-aware developer tools for the authoring and testing of adaptive features and behaviour. We also report on two case studies: the first shows how our general approach allows for integration with existing technologies to leverage advanced context-aware mechanisms in applications developed using other platforms and languages and the second how existing web interfaces can be systematically extended to support new adaptation scenarios.
Interplay of Content and Context
J. Web Eng. 4(1): pp. 57-78 (2005)
We examine the relationship between context engines and content management systems, showing by means of an example... more We examine the relationship between context engines and content management systems, showing by means of an example application how these should mutually interact with each other to ensure the timely delivery of relevant information. We show how a content management system can use context information to enrich its functionality and also how a general and abstract approach to content management can support context awareness. Information models of the general context engine and content management system that we have developed are presented, along with a description of how a symbiotic relationship of content and context can be achieved through the integration of these models.
Database-Driven Web Mashups
Proc. ICWE 2008: pp. 162-174
In most web mashup applications, the content is generated using either web feeds or an application programming... more In most web mashup applications, the content is generated using either web feeds or an application programming interface (API) based on web services. Both approaches have limitations. Data models provided by web feeds are not powerful enough to permit complex data structures to be transmitted. APIs based on web services are usually different for each web application, and thus different implementations of the APIs are required for each web service that a web mashup application uses. We propose a database-driven approach to web mashups that supports integration at the database level and enables mashup developers to work with a uniform abstract model and have direct access to powerful features of database systems. We describe how we have implemented this approach based on an object-oriented database system with a rich object model and a generic proxy mechanism for data integration and synchronisation.
Download (.pdf) Tools for Modeling and Generating Safe Interface Interactions In Web Applications
Proc. ICWE 2010: pp. 482-485
Modern Web applications that embed sophisticated user interfaces and business logic have rendered the original... more Modern Web applications that embed sophisticated user interfaces and business logic have rendered the original interaction paradigm of the Web obsolete. In previous work, we have advocated a paradigm shift from static content pages that are browsed by hyperlinks to a state-based model where back and forward navigation is replaced by a full-fledged interactive application paradigm, featuring undo and redo capabilities, with support for exception management policies and transactional properties. In this demonstration, we present an editor and code generator designed to build applications based on our approach.
Interactive Paper As a Mobile Client for a Multi-Channel Web Information System
World Wide Web 10(4): pp. 529-556 (2007)
We describe how interactive paper can be used together with a multi-channel web information system to build a platform... more We describe how interactive paper can be used together with a multi-channel web information system to build a platform for experimenting with multi-modal context-aware mobile information services. As an application, we present a tourist guide for visitors to an international festival that was developed to investigate alternative modes of information delivery and interaction in mobile environments. The guide is based around a set of interactive paper documents—an event brochure, map and bookmark. The brochure and map are augmented with digital services by using a digital pen to activate links and a text-to-speech engine for information delivery. The digital pen is also used for data capture of event ratings and reviews. The bookmark provides access to advanced searches and ticket reservations. We describe the architecture and operation of the system, highlighting the challenges of extending a web information system to support both the generation of the paper documents and the interaction from these documents, alongside more traditional access channels. Finally, we discuss the range of context-aware interactions that is supported by our platform.
Generic Proxies - Supporting Data Integration Inside the Database
Proc. OTM Workshops 2007: pp. 5-6
Existing approaches to data integration generally propose building a layer on top of database systems to perform the... more Existing approaches to data integration generally propose building a layer on top of database systems to perform the necessary data transformations and manage data consistency. We show how support for the integration of heterogeneous data sources can instead be built into a database system through the introduction of a generic proxy concept.
Modelling Safe Interface Interactions in Web Applications
Proc. ER 2009: pp. 387-400
Current Web applications embed sophisticated user interfaces and business logic. The original interaction paradigm of... more Current Web applications embed sophisticated user interfaces and business logic. The original interaction paradigm of the Web based on static content pages that are browsed by hyperlinks is, therefore, not valid anymore. In this paper, we advocate a paradigm shift for browsers and Web applications, that improves the management of user interaction and browsing history. Pages are replaced by States as basic navigation nodes, and Back/Forward navigation along the browsing history is replaced by a full-fledged interactive application paradigm, supporting transactions at the interface level and featuring Undo/Redo capabilities. This new paradigm offers a safer and more precise interaction model, protecting the user from unexpected behaviours of the applications and the browser.
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An Infrastructure for Reactive Information Environments
Proc. WISE 2005: pp. 347-360
We introduce the concept of reactive information environments and a general infrastructure for experimentation with... more We introduce the concept of reactive information environments and a general infrastructure for experimentation with such systems. Its asynchronous state-based processing model is described along with the architectural requirements and main components of our infrastructure. These include a general context engine coupled together with a web publishing platform. An application for a public news service is used to motivate the requirements, explain the processing model and show how an application is implemented using the platform.
Metatemplate Driven Multi-Channel Presentation
Proc. WISE Workshops 2003: pp. 234-242
The separation of content, layout, structure and view that is enforced by the various emerging content management... more The separation of content, layout, structure and view that is enforced by the various emerging content management systems and Web modelling tools, renders the implementation of suitable editors for content providers very difficult. As most of these systems work on the basis of XML and XSLT and support multiple languages and presentation channels, creating and editing content has become more tedious and challenging. Various attempts at creating graphical XSLT editors have been made but most of them lack the versatility to be used in conjunction with a content management system. In this paper, we present a solution based on generic metatemplates. We then describe how we exploited this approach for an editor integrated into a content management system that we have developed.
Paper-Based Mobile Access to Databases
Proc. SIGMOD 2006: pp. 763-765
Our demonstration is a paper-based interactive guide for visitors to the world's largest international arts festival... more Our demonstration is a paper-based interactive guide for visitors to the world's largest international arts festival that was developed as part of a project investigating new forms of context-aware information delivery and interaction in mobile environments. Information stored in a database is accessed from a set of interactive paper documents, including a printed festival brochure, a city map and a bookmark. Active areas are defined within the documents and selection of these using a special digital pen causes the corresponding query request along with context data to be sent to a festival application database and the response is returned to the visitor in the form of generated speech output. In addition to paper-based information browsing and transactions such as ticket booking, the digital pen can also be applied for data capture of event ratings and handwritten comments on events. The system integrates three main database components - a cross-media information platform, a content management framework for multi-channel context-aware publishing of data and the festival application database.
Java Framework for Database-Centric Web Site Engineering
Proc. WebE 2001: pp. 42-49
We present a database-centric approach to web site development in which both application and web content data are... more We present a database-centric approach to web site development in which both application and web content data are managed by a database. The development process is based on three main stages of information modelling, document content design and presentation specification. A Java framework based on the OMS object-oriented data management system has been developed to support the development life cycle from rapid prototyping through to operation. We describe how the framework supports access from heterogeneous clients and how it has been extended to include a web content manager.
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Modelling Context for Information Environments
Proc. UMICS 2004: pp. 43-56
Context-awareness has become an important consideration in the development of mobile and ubiquitous systems. While... more Context-awareness has become an important consideration in the development of mobile and ubiquitous systems. While efforts have been made to develop general context models and application frameworks, it remains the case that often the notion of context supported is very restrictive and/or the representation of context is based on simple key-value pairs. As a result, most existing systems lack well-defined semantics and typing for context that would facilitate the general implementation, maintenance and adaption of context-aware systems. In this paper, we present a general context model that consolidates the models underlying many other approaches, while moving to a higher-level of abstraction in terms of semantic context description.
Information Concepts for Content Management
Proc. WISE Workshops 2002: pp. 150-159
Content delivery is rapidly emerging as a complex systems domain concerned with multi-channel, multi-format... more Content delivery is rapidly emerging as a complex systems domain concerned with multi-channel, multi-format publication of information across user and application domains. A variety of content management solutions have been developed in response to these challenges based on, not only differing technologies, but also heterogeneous approaches. However, none of these present a solution that is both sufficient and consistent. Here we present an analysis of requirements leading to a general model of the information concepts central to content management. This model is the basis for a web content management solution currently under development.
Interplay of Content and Context
Proc. ICWE 2004: pp. 187-200
We examine general and abstract approaches to web engineering and context-awareness and how they interact with each... more We examine general and abstract approaches to web engineering and context-awareness and how they interact with each other. This involves considering the appropriateness of approaches to context when used by a complex application such as a content management system, while, at the same time, presenting how a content management system can use context information to enrich its functionality. We show that the integration of such systems is feasible only if, in both fields, we make use of approaches based on strong information models. Last but not least, we show that the relationship between context engines and content management systems is not at all a one-sided client-server scenario, but rather a mutually important symbiosis.
Domain-Specific Language for Context-Aware Web Applications
Proc. WISE 2010: pp. 471-479
Context-awareness is a requirement in many modern web applications. While most model-driven web engineering approaches... more Context-awareness is a requirement in many modern web applications. While most model-driven web engineering approaches have been extended with support for adaptivity, state-of-the-art development platforms generally provide only limited means for the specification of adaptation and often completely lack a notion of context. We propose a domain-specific language for context-aware web applications that builds on a simple context model and powerful context matching expressions.
Improvement of a Web Engineering Method Applying Situational Method Engineering
Vlaanderen, K., Valverde, F., & Pastor, O. (2008). Improvement of a web engineering method applying situational method engineering. In J. Cordeiro & J. Filipe (Eds.), Proceedings of the 10th international conference on enterprise information systems (ICEIS 2008) (Vol. ISAS-1, p. 147-154). Barcelona, Spain.
In recent years, the Web Engineering community has introduced several model-driven methods in order to simplify Web... more
In recent years, the Web Engineering community has introduced several model-driven methods in order to simplify Web Application development. However, these methods are too general and mainly focus on data intensive Web Applications. A solution to this problem is the Situational Method Engineering. This approach
allows the creation or improvement of a web engineering method by reusing method fragments from previous methods. This way, a method suitable for a concrete project or domain can be designed. In this work, the OOWS method metamodel is defined with the purpose of applying Situational Method Engineering. Because of this metamodel, OOWS method fragments can be formalised and used to improve the efficiency of another Web Engineering Methods. Furthermore, the suitability of the OOWS method in the context of CMS-based web applications is evaluated through a user-registration case study. The results of this evaluation, is a list of current limitations of the OOWS Method in the CMS Web Systems domain and possible solutions.
Model-driven Web Engineering in the CMS domain: a preliminary research applying SME
Vlaanderen, K., Valverde, F., & Pastor, O. (2008). Model-driven web engineering in the cms domain: a preliminary research applying sme. In Enterprise information systems. Springer-Verlag.
In recent years, the use of Content Management Systems
(CMS) as the core tool to de ne a Web Application has... more
In recent years, the use of Content Management Systems
(CMS) as the core tool to de ne a Web Application has gained popularity. However, the Model-Driven Web Engineering methods are not well tted into the CMS domain. The main reason is that these methods are mainly focusing on the data and navigation aspects. To address this problem we propose in this chapter the use of Situational Method Engineering in order to detect the potential issues and improvements of a Web Engineering method in the CMS domain. Speci cally, the suitability of the OOWS method in the context of CMS-based web applications is evaluated by means of a user-registration use case. From the results of this evaluation, a list of current limitations of the OOWS Method in the CMS domain are detected. Additionally the improvements that can
be applied from a SME perspective are introduced.
On Generating Content and Structural Annotated Websites Using Conceptual Modeling
Casteleyn, S., Plessers, P., De Troyer, O.: "On Generating Content and Structural Annotated Websites using Conceptual Modeling", Proceedings of the 25th International Conference on Conceptual Modeling (ER2006), LNCS 4215, pp. 267-280, Eds. Embley, D.W., Olive, A., Ram, S., Publ. Springer-Verlag, ISBN 3-540-47224-X, Tucson, USA (2006)
An important milestone in the evolution of the Web is the Semantic Web: a Web in which the semantics of the available... more An important milestone in the evolution of the Web is the Semantic Web: a Web in which the semantics of the available content and functionality is made explicit. Web design methods, originally aimed at offering a well- structured, systematic approach to Web design, now face new opportunities and challenges: Semantic Web technology can be used to make the semantics of the conceptual design models explicit; however a major challenge is to (semi-) automatically generate the semantic annotations, effectively enabling the Semantic Web. In this paper, we describe how WSDM, a well-known Web design method, was adapted to use Semantic Web technology for its conceptual modeling and how this can be exploited to generate semantically annotated websites. We consider two types of semantic annotations: content-related annotations and structural annotations. The first type allows to describe the semantics of the content of the website, the latter are annotations that explicitly describe the semantics of the different structural elements used in the website.
Assisting Mobile Web Users: Client-Side Injection of Context-Sensitive Cues into Websites
Casteleyn, S., Van Woensel, W., De Troyer, O.: "Assisting Mobile Web Users: Client-Side Injection of Context-Sensitive Cues into Websites", 12th International Conference on Information Integration and Web-based Applications & Services (iiWAS2010), pp. 441-448, ISBN 978-1-4503-0421-4, Paris, France (2010)
In a mobile setting, the user often browses the Web to consult information related to his current context and... more In a mobile setting, the user often browses the Web to consult information related to his current context and environment: e.g., reviews of nearby restaurants, or tourist information on visited monuments. On the other hand, the limitations of mobile devices (e.g., limited screen) and the peculiarities of mobile Web usage (e.g., walking around, driving a car) make it cumbersome to extensively browse a Web page for such useful information. In this paper, we present a client-side approach that aims to assist the mobile user in his browsing session, by correlating the Web page’s content with the mobile user’s context, and subsequently emphasizing and enriching relevant content with so-called context-sensitive cues. To achieve this, we utilize the SCOUT framework for mobile applications to model and access the user’s context, and RDFa annotations present on existing Web pages to identify Web page elements suitable to enrich with context- sensitive cues. The cues themselves are injected using existing adaptation techniques, borrowed from the field of Adaptive Hypermedia.
A generic approach for on-the-fly adding of context-aware features to existing websites
Van Woensel, W., Casteleyn, S., De Troyer, O., "A generic approach for on-the-fly adding of context-aware features to existing websites", HT'11, Proceedings of the 22nd ACM Conference on Hypertext and Hypermedia, Eindhoven, The Netherlands, June 6-9, 2011. ACM 2011, ISBN 978-1-4503-0256-2, pp. 143-152
More and more, mobile devices act as personal information managers and are able to obtain rich contextual information... more More and more, mobile devices act as personal information managers and are able to obtain rich contextual information on the user’s environment. Mobile, context-aware web applications can exploit this information to better address the needs of mobile users. Currently, such websites are either developed separately from their associated desktop-oriented version, or both versions are created simultaneously by employing methodologies that support multi- platform context-aware websites, requiring an extensive engineering effort. While these approaches provide a solution for developing new websites, they go past the plethora of existing websites. To address this issue, we present an approach for enhancing existing websites on-the-fly with context-aware features. We first discuss the requirements for such an adaptation process, and identify applicable adaptation methods to realize context-aware features. Next, we explain our generic approach, which is grounded in the use of semantic information extracted from existing websites. Finally, we present a concrete application of our approach that is based on the SCOUT framework for mobile and context-aware application development.