1. Bridging EMF applications and RDF Data Sources Guillaume Hillairet, Frédéric Bertrand, Jean Yves Lafaye {guillaume.hillairet01, fbertran, jylafaye}@univ-lr.fr Laboratoire L3I, Université de La Rochelle, France. SWESE08: Semantic Web Enabled Software Engineering @ ISWC08. 26 October 2008

2. SWESE'082Agenda Semantic Web Applications Modeling Support for Semantic Web Apps emf4sw: Eclipse Modeling Framework for Semantic Web Conclusion

3. SWESE'083 refers to Semantic Web Applications described by access rdf data provides

4. SWESE'084 Semantic Web Applications Web Applications: Centralized, fixed schema, single data source … Semantic Web: Decentralized, arbitrary schema, many data sources … From Web to Semantic Web Applications: Using Semantic Web data in existing Web Applications. Embedding Semantic Web data in common web development processes. Our contribution: Modeling support for Semantic Web Applications. Use of RDF Data as EMF Objects Similar approaches: ActiveRDF, Topaz platform, …

5. SWESE'085 Modeling Semantic Web Applications JSF/HTMLGeneration SQLGeneration OWL/RDF(S)Generation User Interface Relational Persistence Semantic Web Data

6. SWESE'086emf4sw Uses Eclipse Modeling Framework (EMF). Links EMF applications with RDF Data Sources: Mapping between OWL Ontology and EMF Model. Load RDF data into M1 model. Save M1 Model into RDF. Manipulate RDF Data as EMF Objects. Acts as an ORM but for RDF data.

7. SWESE'087 emf4sw: main components Resource Provider Object/Ontology Mapping. Loads/Saves objects. Model Manager Manages EMF Resources Provides Model Transformations Query Engine Builds queries. Provides query rewriting: HQL to SPARQL, SPARQL to HQL. Data Source Manager Accesses online data sources (SPARQL endpoints, …). Supports access to multiple data sources. Distributes/Federates query results.

8. SWESE'088 emf4sw usage: initialization First generate Java Classes from EMF Model. Then, init a resource provider: Add EPackages corresponding to the EMF Model Add corresponding mapping file Adding an RDF Data Source (RDF File, RDF DB, SPARQL endpoint):

9. SWESE'089 Object/Ontology mapping Need to explicitly define links between EMF Model and OWL Ontology Proposition Mapping language for Ecore/OWL Map Ecore & OWL (MEO)

10. SWESE'0810 Object/Ontology Mapping Mapping EMF Classes to OWL Classes Map one EClass to one OWLClass Map one EClass to many OWLClass Have different views on same EClass, Use of OCL constraints to define views.

11. SWESE'0811 Object/Ontology Mapping Mapping EStructuralFeatures to OWLProperties Map EAttribute to DataProperty Map EReference to ObjectProperty

12. SWESE'0812 Object/Ontology Mapping

13. SWESE'0813 OOM: Model Transformations

14. SWESE'0814 emf4sw: Loading and Saving objects Loading an EObject: Saving an EObject: Loading/Saving EMF Resources:

15. SWESE'0815 emf4sw: Querying RDF Data Source Query RDF Data Source in HQL: Or directly in SPARQL:

16. SWESE'0816Conclusion The goal of our approach is to ease import/export of Semantic Web data within current applications. Object/Ontology mapping is necessary for embedding Semantic Web data in current applications (not only Web App.). Model Driven Engineering simplifies and automates implementation and use of such complex process. Well defined OWL ontologies are needed for describing RDF data sources.

17. SWESE'0817 Thank you, Questions ?