Talk at the JAX 2009 in Mainz (Germany)

1. Dr. Jan Köhnlein, itemis AG
EMF – Beyond the Basics

3. Eclipse Modeling
Framework

4. Eclipse Modeling
Framework
• Create Ecore models

5. Eclipse Modeling
Framework
• Create Ecore models
• from Java, XSD, UML, MOF

6. Eclipse Modeling
Framework
• Create Ecore models
• from Java, XSD, UML, MOF
• or from scratch

7. Eclipse Modeling
Framework
• Create Ecore models
• from Java, XSD, UML, MOF
• or from scratch
• Generate Java-Code from Ecore

8. Eclipse Modeling
Framework
• Create Ecore models
• from Java, XSD, UML, MOF
• or from scratch
• Generate Java-Code from Ecore
• Runtime library to process Ecore models
and instances

9. Ecore
EPackage EClassifer
* name:String
name: String
eClassifiers
nsURI: String
eSuperTypes
*
EClass EDatatype
abstract: boolean
eReferenceType
eAttributeType
* eStructuralFeatures
EStructuralFeature
name: String
lowerBound: int
upperBound: int
EReference EAttribute
containment: boolean
*
eOpposite

10. Ecore Instances

11. Ecore Instances
• EObject

12. Ecore Instances
• EObject
• Instance of an EClass

13. Ecore Instances
• EObject
• Instance of an EClass
• Values for EAttributes

14. Ecore Instances
• EObject
• Instance of an EClass
• Values for EAttributes
• References for EReferences

15. Ecore Instances
• EObject
• Instance of an EClass
• Values for EAttributes
• References for EReferences
• Ecore is self-describing

16. Ecore Instances
• EObject
• Instance of an EClass
• Values for EAttributes
• References for EReferences
• Ecore is self-describing
• EClass, EPackage etc. extend EObject

17. Example Ecore/Instance
<< EPackage >> <<Node>>
TreePackage parent parent
myNode0
name: quot;Treequot;
nsURI: quot;http://www.itemis..quot;
<<EClass>>
Node
name: quot;Nodequot;
children
abstract: false
<<EReference>> << EReference >>
children parent
name: quot;childrenquot; name: quot;parentquot;
containment: true containment: false
<< Node >> << Node >>
upperBound: -1 upperBound: 1
myNode2 myNode1
lowerBound: 0 lowerBound: 0
eOpposite eOpposite

18. Example: Java View
TreePackage::EPackage
name: quot;Treequot;
myNode0::Node
nsURI: quot;http://www.itemis..quot; parent
Node::EClass
name: quot;Nodequot;
children
abstract: false
::EList
children::EReference parent::EReference
name: quot;childrenquot; name: quot;parentquot;
containment: true containment: false
upperBound: -1 upperBound: 1
myNode1::Node
lowerBound: 0 lowerBound: 0
eOpposite eOpposite

19. Example: Java View
TreePackage::EPackage
name: quot;Treequot;
myNode0::Node
nsURI: quot;http://www.itemis..quot; parent
Node::EClass
name: quot;Nodequot;
children
abstract: false
::EList
children::EReference parent::EReference
name: quot;childrenquot; name: quot;parentquot;
containment: true containment: false
upperBound: -1 upperBound: 1
myNode1::Node
lowerBound: 0 lowerBound: 0
eOpposite eOpposite
Node myNode0 = TreeFactory.eINSTANCE.createNode();
Node myNode1 = TreeFactory.eINSTANCE.createNode();
myNode0.getChildren().add(myNode1);

20. Ecore Reflection
EStructuralFeature
* eStructuralFeatures
EClass EObject eContents
eClass
getEStructuralFeature(String): eGet(EStructuralFeature): Object
EStructuralFeature eSet(EStructuralFeature, Object) *
* eClassifiers eContainer
EPackage EFactory
eFactory
getEClassifier(String):EClassifier create(EClass):EObject

21. Dynamic EMF
// load Ecore file
URI resourceURI = URI.createPlatformResourceURI(
quot;de.itemis.treemodel/model/treemodel.ecorequot;, true);
Resource resource = new XMIResourceImpl(resourceURI);
// extract Ecore model
EPackage treePackage = (EPackage) resource.getContents().get(0);
EFactory factory = treePackage.getEFactoryInstance();
EClass nodeClass = (EClass) treePackage.getEClassifier(quot;Nodequot;);
EStructuralFeature childrenReference =
nodeClass.getEStructuralFeature(quot;childrenquot;);
// create instances using reflective API
EObject myNode0 = factory.create(nodeClass);
EObject myNode1 = factory.create(nodeClass);
((EList) myNode0.eGet(childrenReference)).add(myNode1);

22. References

23. References

24. References
Resource
Element
Element
Element
Element Element
Element
Element Element
Element Element
Element
Element
Element
Element Element
Element Element
Element
Element Element
Element Element Element
Element
Element
Element
Element
Element Element Element
Element Element
Element Element
Element

25. References
Resource
Element
Element
Element
Element Element
Containment
Element
Element Element
Element Element
Element
Element
Element
Element Element
Element Element
Element
Element Element
Element Element Element
Element
Element
Element
Element
Element Element Element
Element Element
Element Element
Element

26. References
Resource
Element
Element
Element
Element Element
Containment
Element
Element Element
Element Element
Element
Element
Element
Element Element
Element Element
Element
Element Element
Element Element Element
Element
Element
Element
Element
Element Element Element
Element Element
Element Element
Element
Cross-References

27. References
Resource
Resource
Containment
Element
Element
Element
Element Element
Containment
Element
Element Element
Element Element
Element
Element
Element
Element Element
Element Element
Element
Element Element
Element Element Element
Element
Element
Element
Element
Element Element Element
Element Element
Element Element
Element
Cross-References

28. Big Models

29. Lots of elements...
Big Models

30. Lots of elements...
Big Models
...and lots of references

31. Divide
&
Conquer

33. Resource
Element
Element
Element Element
Element
Element
Element
Element
Element Element
Element
Element
Element
Element Element
Element
Element
Element Element
Element
Element
Element Element
Element
Element
Element
Element Element
Element

34. ResourceSet
Resource Resource
Resource Resource
Element Element
Element Element
Element
Element Element
Element Element Element
Element Element
Element Element Element
Element Element
Element Element
Element Element
Element Element
Element Element Element Element
Element Element

35. Lazy Loading

36. Proxy
EObject
• Not yet loaded EObject
eIsProxy(): boolean
• Instantiated on load for InternalEObject
external reference
eProxyURI(): String
eSetProxyURI(String)
• eProxyURI attribute set
• Replaced on resolution
EObjectImpl
EcoreUtil
resolve(EObject, ResourceSet)
resolve(EObject, Resource)
resolve(EObject, EObject)

37. Proxy Resolution
ResourceSet
Resource
PROXY
Element
Element
Element Element

38. Proxy Resolution
ResourceSet
Resource
PROXY
Element
Element
Element Element

39. Proxy Resolution
ResourceSet
Resource Resource
PROXY
Element
Element
Element Element

40. Proxy Resolution
ResourceSet
Resource Resource
Element
PROXY
Element
Element
Element
Element Element
Element Element
Element

41. Proxy Resolution
ResourceSet
Resource Resource
Element
PROXY
Element
Element
Element
Element Element
Element Element
Element

42. How about unloading?
ResourceSet
Resource
Resource Resource
(unloaded)
PROXY
Element
Element
PROXY
Element
Element
Element Element
PROXY PROXY
Element Element
PROXY
Element

43. How about unloading?
ResourceSet
Resource
Resource Resource
(unloaded)
PROXY
Element
Element
PROXY
Element
Element
Element Element
PROXY PROXY
Element Element
PROXY
Element

44. How about unloading?
ResourceSet
Resource
Resource Resource
(unloaded)
PROXY
Element PROXY
Element
PROXY
Element PROXY
Element
Element Element
PROXY PROXY
Element Element PROXY PROXY
PROXY
Element PROXY

45. Lazy Loading
• Proxy Resolution / Lazy Loading
• Transparently when navigating references
• Unload
• Proxifies elements
• Keeps elements connected by default

46. Enabling Proxies
• For cross-references
• Set
EResource.isResolveProxies
• For containment references
• Additionally set
GenModel.isContainmentProxies

47. eProxyURI
• Resource URI + Fragment
[scheme:][//authority][/path][#fragment]
• Examples:
http://www.itemis.de/files/model.ecore#/
file:/Users/koehnlein/test.xmi#/children.0
platform:/resource/myproject/m2.uml#12345126

48. Resource URIs
• Relative or absolute URIConverter
normalize(URI): URI
createInputStream(URI): InputStream
createOutputStream(URI): OutputStream
• URIConverter
exists(URI)
delete(URI)
getURIMap(): Map<URI, URI>
• Resolves URIs
• Access to resources
ExtensibleURIConverter
• Abstraction on
*
URIHandler
canHandle(URI): boolean
createInputStream(URI): InputStream
I/O Access createOutputStream(URI): OutputStream
exists(URI)
delete(URI)

49. Fragment
Strategies

50. Fragment Paths
::Resource
uri=quot;http://www.itemis.de/model.treequot;
• Example
0
::Node
• #/0/children.3
• Compact
children
• Fragile with respect
.1 .2 .3
::Node
to reorderig
::Node
::Node

51. Fragment Paths With Keys
• Define EAttribute as key
::Resource
uri=quot;http://www.itemis.de/model.treequot;
for EReference
0
• Example
::Node
name=quot;rootquot;
• name key of children
children
•
.Sven .Peter .Ed
#/0/children.Ed
::Node
name=quot;Svenquot;
• Assert no collisions !
::Node
name=quot;Peterquot;
::Node
name=quot;Edquot;

52. EAttributes as ID
::Resource
uri=quot;http://www.itemis.de/model.treequot;
• Set ID flag on EAttribute
0
• Example
::Node
index=0
• index defined as ID
• #3
1 2 3
::Node
• Initialize without collisions
index=1
::Node
index=2
::Node
index=3

53. Extrinsic IDs
::Resource
uri=quot;http://www.itemis.de/model.treequot;
eObjectToIDMap = {...}
• Resource manages IDs
::Node
index=0
• Example
quot;ab3827d8quot;
• #276fe78d
• UUIDs in UML2
::Node
::Node
quot;37fe34c2quot;
::Node
quot;87f33bd2quot;
quot;276fe78dquot;

54. Tracking Inverse
References

55. ECrossReferenceAdapter
Adapter
notifyChanged(Notification)
isAdapterForType(Object): boolean
• Works for loaded
Resources within EContentAdapter
a ResourceSet
ECrossReferenceAdapter
getInverseReferences(EObject): List<Setting>
getNonNavigableReferences(EObject): List<Setting>

56. EMF Index
• Indexes all resources in workspace
• Query elements and cross-references

57. EMF Index
• Indexes all resources in workspace
• Query elements and cross-references
Load
Resources

58. EMF Transactions

59. EMF Transactions

60. EMF Transactions
TransactionChangeRecorder
beginRecording() ResourceSet
endRecording()
CommandStack
TransactionalEditingDomain
execute(Command)
runExclusive(Runnable): Object
undo()
redo()
RecordingCommand
execute()

61. Global Singletons

62. Global Singletons

63. Global Singletons
• Configured with Eclipse extensions

64. Global Singletons
• Configured with Eclipse extensions
• EPackage.Registry:
Dynamic and static Ecore models

65. Global Singletons
• Configured with Eclipse extensions
• EPackage.Registry:
Dynamic and static Ecore models
• Resource.Factory.Registry
Resource implementations

66. Global Singletons
• Configured with Eclipse extensions
• EPackage.Registry:
Dynamic and static Ecore models
• Resource.Factory.Registry
Resource implementations
• (Extensible)URIConverter

67. Global Singletons
• Configured with Eclipse extensions
• EPackage.Registry:
Dynamic and static Ecore models
• Resource.Factory.Registry Override
Resource implementations in
• (Extensible)URIConverter Resource
Set

68. Questions?