Persist Ecore models to RDF, or use Active Objects and Reflection to hold active object state in RDF. These slides were presented as a lightning talk at Code Generation 2013 <http: />.

1. Model Reflection in RDF
Steve Battle
@stevebattle

2. Introduction
• Based at the Bristol and Bath Science Park.
• Aerospace and Advanced Manufacturing.
• Model Driven Architecture and Development.
Successes :
• DSL based service configuration
• Model Driven Architecture Evaluation
• Model Driven 3D Printing
• Linked Data and Ontology

3. Purchase-Order MetaModel
Sharing of models between applications is hard:
• Code dependency.
• Wrong level of modularization for Services.
• Alternative Views.

4. Resource Description
RDF : Resource Description Framework <www.w3.org/RDF>
• URIs name resources
• Share data not objects
• Self-describing (schema-less)

5. Resource vs. Object Orientation
public interface PurchaseOrder extends EObject {
String getShipTo();
void setShipTo(String value);
String getBillTo();
void setBillTo(String value);
EList<Item> getItems();
}
External view
• Model reflection in RDF
• Shared ontology in OWL
• Loose coupling
• Resource Orientation
Internal view
• System model
• Code Generation
• Object Orientation
Model Driven
• Ecore Meta-Model
• Architecture Evaluation

6. Persistence and Reflection
• Ecore Persistence framework
– ResourceSet supplies the base URI
e.g. http://example.com/po.rdf
– RDF Resource defines a hash URI
e.g. http://example.com/po.rdf#/0
http://example.com/po.rdf#/0/@items.0
– Benefit : Exchange objects by URI reference
• Active Objects and Reflection
– RDF EStore holds active object state in RDF model
– Generated classes use reflective methods eGet(),eSet(), …
– Generated implementations extend custom EStoreEObjectImpl
– Benefit : Lazy object construction resolves URIs on demand

7. SPARQL Query
• Query across models (aspect orientation?)
• Expose models as linked-data
PREFIX po: <http://example.com/#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT * WHERE {
?po a po:PurchaseOrder ;
po:PurchaseOrder_billTo ?bill ;
po:PurchaseOrder_items [ rdfs:member ?item ] .
?item a po:Item ;
po:Item_quantity ?qty ;
po:Item_price ?price .
OPTIONAL { ?item po:Item_productName ?product }
}

8. Summary
• Comments, ideas, applications?
steve.battle@sysemia.co.uk
Bristol & Bath Science Park,
Dirac Crescent,
Emerson's Green,
Bristol.