Engineering the Presentation Layer of Adaptable Web Information

Engineering the Presentation Layer of Adaptable Web Information Systems Zoltán Fiala 1, Flavius Frasincar 2, Michael Hinz 1, Geert-Jan Houben 2, Peter Barna 2, Klaus Meissner 1 1 Technische Universität Dresden 2 Technische Universiteit Eindhoven {zoltan. fiala, mh 5, kmeiss}@inf. tu-dresden. de {flaviusf, houben, pbarna}@win. tue. nl ICWE 2004, 28 -30 2004, Munich ICWE 2004, July 28 -30

Structure n n n Motivation Hera Design Methodology Presentation Layer – Adaptation in the PL n AMACONT – Component-based Document Format – Layout Manager n n 1 Realizing the Hera PL with AMACONT Conclusion and Future Work ICWE 2004, July 28 -30 2004, Munich

Motivation n Adaptive Web Information Systems – Dynamic publication of up-to-date information, adapted to both user preferences and client platforms – Complex development process -> Need for systematic design methodologies » Specify hypermedia applications in an appropriate level of abstraction » Help designers and programmers to proceed in a structured way n Hera – Model-driven design methodology » Conceptual, navigational, and presentation design – Uses Semantic Web technologies (RDF/RDFS) for explicit model semantics – Identifies adaptation hot spots in each design model – Previously: » Missing formalization of the presentation model » Adaptation not implemented in the presentation layer 2 ICWE 2004, July 28 -30 2004, Munich

Motivation n AMACONT project – Component-based Development of Adaptive Web Presentations – Composition of adaptive Web applications by the aggregation and linkage of reusable document components – Special focus on adaptive presentation layer: layout managers – Previously: » No focus on design process » Missing high-level specifications n Hera-AMACONT cooperation – Combination of Hera’s modeling power with AMACONT’s flexible adaptive presentation layer – Adoption of AMACONT’s layout managers to the Hera PM – Benefits: » Automatic translation of Hera models to an AMACONT implementation » Versatile implementation (presentation) layer for Hera » Complete specification framework with automatic presentation generation 3 ICWE 2004, July 28 -30 2004, Munich

Hera- Conceptual Design n Conceptual Model (CM) – Represents the application domain by concepts and concept attributes – Based on RDFS n Media Model – Submodel of CM – Hierarchically composed of media types – Adapting media quality by conditional inclusion of media variants 4 ICWE 2004, July 28 -30 2004, Munich

Hera - Application Design Application Model n – Logical, structural and navigational aspects – Grouping concept attributes to Slices – Slice: meaningful presentation unit of some media items – Adaptation Design: » Assigning appearance conditions to slice references 5 ICWE 2004, July 28 -30 2004, Munich

Presentation Design n Presentation Design – Important aspect of hypermedia modeling – Declares the „look and feel” of a Web application independent from its implementation – Utilizes abstract user interface elements for layout composition – Adaptation required to » Users‘ layout preferences » Presentation capabilities of client devices » System environment 6 ICWE 2004, July 28 -30 2004, Munich

Presentation Layer Adaptation n Media adaptation to technical system parameters – Bandwidth, display resolution, color depth – Providing quality alternatives of selected media elements n Corporate Design – Look-and-feel: background colors, fonts, icons etc. – Users’ layout preferences and visual impairments – External parameters: seasons, anniversaries 7 ICWE 2004, July 28 -30 2004, Munich

Presentation Layer Adaptation n Spatial and temporal adjustment of layout elements – Reorganization » Adapting the arrangement of layout elements – Excluding » Information being unsuitable for a particular browser » Design elements without specific semantic meaning – Separation » Putting certain content pages to separate pages » Dynamic generation of links to those pages n Dynamic Adaptation – According to users’ changing browsing behavior » Dynamical browser window resizing – Environmental events: » bandwidth fluctuation 8 ICWE 2004, July 28 -30 2004, Munich

AMACONT n 9 Component-based Web Application Development ICWE 2004, July 28 -30 2004, Munich

AMACONT n Adaptive Layout – Layout Managers : XML-based abstract layout descriptions – Inspired by Java – Describe the spatial arrangement of immediate subcomponents – – Overlay. Layout Box. Layout Border. Layout Grid. Layout – XSLT Transformers » x. HTML » c. HTML » WML 11 ICWE 2004, July 28 -30 2004, Munich

Layout Manager Example Layout attributes Subcomponent attributes 12 ICWE 2004, July 28 -30 2004, Munich

Hera - Presentation Model n Analogies between Hera slices and components: – Meaningful presentation units bearing some semantic role – Both top-level slices and top-level document components correspond to pages shown on the user’s display – Contain adaptation issues n Presentation Model (PM) – Adopting AMACONT’s layout managers – Assigning layout managers to Hera Slices – Formalization in RDF(S) – Result: Automatic mapping to an AMACONT implementation 13 ICWE 2004, July 28 -30 2004, Munich

Data Transformation Process 14 ICWE 2004, July 28 -30 2004, Munich

Data Transformation Process Application Model Instance Unfolding Transforming AM Instances to AMACONT components 15 Adding layout managers to components according to Hera PM ICWE 2004, July 28 -30 2004, Munich Transforming components to different output formats

Prototype: Component-based WIS 16 ICWE 2004, July 28 -30 2004, Munich

Conclusion and Future Work n Conclusion – Aspects of presentation layer adaptation in WIS design – Adoption of AMACONT’s layout managers to the Hera design framework – Formalization of Hera’s Presentation Model – Integrated framework » Automatic Mapping of high-level specifications to a component-based implementation n 17 Future Work – Dynamic coupling of AMACONT and Hera – Feedback mechanisms for dynamically reacting on user input – Acquirement and evaluation of user interactions – Utilizing AMACONT components in all Hera layers – Realizing dynamic adaptation (adaptivity) in the joint system ICWE 2004, July 28 -30 2004, Munich

Layout Editor 18 ICWE 2004, July 28 -30 2004, Munich