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This paper presents an innovative methodology for automated hypermedia presentation design using Relationship Management Methodology (RMM). It addresses the growing need for effective presentation automation in Web-based Information Systems that serve data from heterogeneous sources. The proposed approach leverages the relatively unexplored Deep Web and supports adaptation to various user requirements, including preferences and device capabilities. The methodology encompasses a logical level for data structuring and a presentation level for visual representation, facilitating dynamic information delivery across platforms.
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An RMM-Based Methodology for Hypermedia Presentation Design Flavius Frasincar Richard Vdovjak Geert-Jan Houben Databases & Hypermedia Group Department of Informatics ADBIS'2001
Contents • Motivation • Goals • Context: Hera Architecture • Design Methodology • Application Diagram • Presentation Diagram • Prototype: XML/XSL • Further Work ADBIS'2001
1. Motivation • There are a lot of methodologies for manual hypermedia presentation design but not for an automatic one. • The need for presentation automation is justified by the fact that a lot of data is nowadays residing in the heterogeneous ‘deep web’ (searchable databases) as opposed to the ‘surface web’. • There is an increasing need for presentation adaptation for different users/user platforms. ADBIS'2001
Deep Web • Deep Web vs. Surface Web: • 500 times larger • 1000 times better quality ADBIS'2001
2. Goals Develop a methodology that supports automated hypermedia presentation design for Web-based Information Systems (WIS) that: • Integrates heterogeneous data sources. • Facilitates presentation (server/client-side) adaptation: • Network (T1, 128K, 56K etc.) • Display (PC, Palm, WAP Phone etc.) • User (preferences, interaction history etc.) • Enables semi-structured data queries. ADBIS'2001
Relational Database Object-Oriented Database XML Database … RDB-XML Wrapper ODB-XML Wrapper Mediator/ Integrator Information Retrieval Hypermedia Presentation Logical Presentation Logical-HTML Presentation Logical-WML Presentation Logical-SMIL Presentation HTML Presentation WML Presentation SMIL Presentation Query … 3. Context: Hera Architecture ADBIS'2001
4. Design Methodology • Based on RMM (Relationship Management Methodology). • It distinguishes two levels: • Logical level: groups data into meaningful content units, called Slices. • Artifact: Application Diagram • Presentation level: translates slices to presentation units, called Regions. • Artifact: Presentation Diagram ADBIS'2001
Methodology Phases Application Design Presentation Design Requirements Analysis E-R Design Implementation E-R Diagram Application Diagram Presentation Diagram Phase Artifacts: • Slice • Slice Relationship • Region • Region Relationship • Entity • Relationship (Application Model) (Conceptual Model) (Presentation Model) ADBIS'2001
5. Application Diagram • Based on the concept of slice which groups together attributes (having specific media types) and possibly other slices. • Extends the E-R Diagram, each slice belongs to an entity. • Slices are linked together with slice relationships: • Aggregation relationships: index, tour, indexed guided tour etc. • Reference relationships: link with an anchor specified. ADBIS'2001
Application Diagram Example ADBIS'2001
6. Presentation Diagram • Based on the concept of region which contains attributes and possibly other regions. • Each region has a rectangular area associated. • Slices are translated to regions, one slice can be mapped to several regions. • Slice relationships are materialized with: • Navigational relationships • Spatial relationships • Temporal relationships ADBIS'2001
Region Relationships • All region relationships can be guarded by a condition and/or an event. • Navigational relationships: represent the classical hyperlinks. Possible events are: mouse-click, mouse-over etc. • Temporal relationships: have associated a timeout event (e.g. time based on a media play duration). • Spatial relationships: specify a relative position (qualitative or quantitative) between two regions. ADBIS'2001
Presentation Diagram Example ADBIS'2001
Synchronization Petri-net like notation for expressing synchronization (typical for multimedia data). • Temporal • Multidimensional ADBIS'2001
7. Prototype: XML/XSL • Implements the logical level of the design methodology. • Based on transformation steps encoded in XSL stylesheets that describe to an XSLT processor how to convert the input XML file to the desired output XML file. • Tool: XSLT processor from Apache XML Project. ADBIS'2001
Prototype Steps ADBIS'2001
Data Retrieval • Retrieved data is an instance of the conceptual model. DTD XML <entity-class id=“entity.painter”> <entity-instance id=“ID_0”> <attribute-instance id=“attribute.painter.name”> <![CDATA[Rembrandt Harmensz. van Rijn]]> </attribute-instance> </entity-instance> </entity-class> <!ELEMENT entity-class (entity-instance)*> <!ATTLIST entity-class id ID> <!ELEMENT entity-instance (attribute-instance)*> <!ATTLIST entity-instance id ID> <!ELEMENT attribute-instance (#PCDATA)> <!ATTLIST attribute-instance id CDATA> ADBIS'2001
Data Cleaning • Enriches the retrieved data with information from the application domain model (appropriate relationship names, inverse of relationship instances). XSL <xsl:when test=“@id=‘painting-technique’”> <xsl:attribute name=“id”>relationship.exemplifies</xsl:attribute> </xsl:when> ADBIS'2001
Application Model • Describes at logical level the hypermedia aspects of the application. DTD XML <!ELEMENT slice (text | (slice-ref | hyperlink | index | guided-tour))> <!ATTLIST slice id ID> <!ATTLIST slice owner IDREF> <slice id=“slice.painting.main” owner=“entity.painting”> <slice-ref idref=“attribute.painter.name”> relationship-ref=“relationship.painted_by”/> … </slice> ADBIS'2001
Logical Transformation Generation • Builds the main transformation engine that packages the retrieved data into slices using the application model. <xsl:stylesheet xmlns:xsl=“http://www.w3.org/1999/XSL/Transform” xmlns:axsl=“http://www.w3.org/1999/XSL/TransformAlias”> <xsl:template match=”/”> <axsl:stylesheet> <axsl:template match=”/”> … </axsl:template> </axsl:stylesheet> </xsl:template> … </xsl:stylesheet> XSL ADBIS'2001
Logical Transformation • Packages the retrieved data into slices based on the stylesheet generated by the previous step. XSL <text> <axsl:value-of select=“attribute-instance[@id=‘attribute.painting.main’]”/> </text> ADBIS'2001
Presentation Transformation • Implements the presentation. • There are two code generators built for: HTML and WML. WML XSL HTML XSL <xsl:template match=“slice-instance”> <TABLE> <xsl:apply-templates select=“*”/> </TABLE> </xsl:template> <xsl:template match=“slice-instance”> <CARD id=“{@id}”> <xsl:apply-templates select=“*”/> </CARD> </xsl:template> ADBIS'2001
8. Further Work • Add media types to the model (now: strings and URLs). • Build slices-on-demand on a servlet (now: precomputed). • Implement the presentation level of the proposed methodology. • Make use of query technologies for XML and RDF: XQuery and RQL (now: SQL). • Experiment with different kinds of applications (e.g. Electronic TV-Program Guide). • Use Semantic Web: model descriptions in RDF(S). • Taxonomies of classes/properties based on inheritance. ADBIS'2001