Engineering the Presentation Layer of Adaptable Web Information Systems

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Engineering the Presentation Layer of Adaptable
Web Information Systems

• Zoltán Fiala1, Flavius Frasincar2, Michael Hinz1,
  Geert-Jan Houben2, Peter Barna2, Klaus Meissner1
• 1Technische Universität Dresden
• 2Technische Universiteit Eindhoven
• zoltan.fiala, mh5, kmeiss_at_inf.tu-dresden.de
• flaviusf, houben, pbarna_at_win.tue.nl

ICWE 2004, July 28-30 2004, Munich
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Structure

• Motivation
• Hera Design Methodology
• Presentation Layer
• Adaptation in the PL
• AMACONT
• Component-based Document Format
• Layout Manager
• Realizing the Hera PL with AMACONT
• Conclusion and Future Work

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Motivation

• Adaptive Web Information Systems
• Dynamic publication of up-to-date information,
  adapted to both user preferences and client
  platforms
• Complex development process -gt Need for
  systematic design methodologies
• Specify hypermedia applications in an appropriate
  level of abstraction
• Help designers and programmers to proceed in a
  structured way
• 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

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Motivation

• 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
• Hera-AMACONT cooperation
• Combination of Heras modeling power with
  AMACONTs flexible adaptive presentation layer
• Adoption of AMACONTs 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

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Hera- Conceptual Design

• Conceptual Model (CM)
• Represents the application domain by concepts
  and concept attributes
• Based on RDFS
• Media Model
• Submodel of CM
• Hierarchically composed of media types
• Adapting media quality byconditional inclusion
  ofmedia variants

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Hera - Application Design

• Application Model
• 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

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Presentation Design

• 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

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Presentation Layer Adaptation

• Media adaptation to technical system parameters
• Bandwidth, display resolution, color depth
• Providing quality alternatives of selected media
  elements
• Corporate Design
• Look-and-feel background colors, fonts, icons
  etc.
• Users layout preferences and visual impairments
• External parameters seasons, anniversaries

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Presentation Layer Adaptation

• 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
• Dynamic Adaptation
• According to users changing browsing behavior
• Dynamical browser window resizing
• Environmental events
• bandwidth fluctuation

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AMACONT

• Component-based Web Application Development

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Beschreibung adaptiven Verhaltens
ltAmaDocumentComponent name"TVProgram"gt ltMetaInfo
rmationgt ... lt/MetaInformationgt ltVaria
ntsgt ltVariant name"Adult_Program"gt ... lt/V
ariantgt ltVariant name"Child_Program"gt ...
lt/Variantgt lt/Variantsgt lt/AmaDocumentComponentgt
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AMACONT

• Adaptive Layout
• Layout Managers XML-based abstract layout
  descriptions
• Inspired by Java
• Describe the spatial arrangement of immediate
  subcomponents
• OverlayLayout
• BoxLayout
• BorderLayout
• GridLayout
• XSLT Transformers
• xHTML
• cHTML
• WML

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Layout Manager Example
Layout attributes
Subcomponent attributes
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Hera - Presentation Model

• 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
  users display
• Contain adaptation issues
• Presentation Model (PM)
• Adopting AMACONTs layout managers
• Assigning layout managers to Hera Slices
• Formalization in RDF(S)
• Result Automatic mapping to an AMACONT
  implementation

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Data Transformation Process
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Data Transformation Process
Application Model Instance Unfolding
Transforming AM Instances to AMACONT components
Adding layout managers to components according to
Hera PM
Transforming components to different output
formats
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Prototype Component-based WIS
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Conclusion and Future Work

• Conclusion
• Aspects of presentation layer adaptation in WIS
  design
• Adoption of AMACONTs layout managers to the Hera
  design framework
• Formalization of Heras Presentation Model
• Integrated framework
• Automatic Mapping of high-level specifications to
  a component-based implementation
• 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

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Layout Editor