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Difference between revisions of "VIATRA/Transformation/Transformation API"
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Model manipulation primitives are implemented by instances of IModelManipulations interface. Currently, two implementations are available: | Model manipulation primitives are implemented by instances of IModelManipulations interface. Currently, two implementations are available: | ||
| − | + | # SimpleModelManipulations - uses plain EMF API | |
| − | + | # ModelManipulationsWithEditingDomain - uses EMF Edit commands on EditingDomain instances | |
If some transformation needs specific primitives (e.g. transaction support), new instances can introduce extra methods as required. | If some transformation needs specific primitives (e.g. transaction support), new instances can introduce extra methods as required. | ||
Revision as of 10:47, 20 September 2013
Contents
VIATRA2 EMF Transformation API
- Based on EVM
- Relies on Xtend features such as extension methods and closures to be
- Language concepts (for requirements overview)
- Documentation for API in org.eclipse.viatra2.emf.git (browse, stats, fork on OrionHub)
Batch Transformation API
Three extension classes used for transformations:
- BatchTransformation - hides IncQueryEngine and RuleEngine; manages group initialization of rules - instead of an extension method, this can also be used as a base class
- TransformationStatements - control structure
- ModelManipulation - generic model manipulation primitives; hides details of EditingDomains (if necessary); implementation not batch transformation specific
Batch Transformation Rules
- Special rule type
- Precondition + action
- Life cycle:
- Stateless
- rule does not maintain state whether an activation has fired or not
- Lifecycle: firing: active -> active
- Stateful
- rule maintains whether an an activation has fired or not
- Lifecycle: firing: active -> fired
- Stateless
(Batch) Transformation Statements
| Name | Parameters | Description |
|---|---|---|
| choose | Batch Transformation Rule, (opt: filter) | Fires a single activation |
| forall | Batch Transformation Rule, (opt: filter) | Fires all current activations. If the firings change the set of activations, it won't change the set of fired activations. |
| until | Batch Transformation Rule, break condition, (opt: filter) | After firing the first activation, it checks whether the break condition became true; if yes, exits, if not, it restarts. It does not store the initial set of activations. Useful for iterate-choose scenarios. Break conditions are implemented using Match Predicates - functions that receive Match instances as parameters. |
| find | IQuerySpecification, (opt: filter) | Returns a match of a selected query |
Incremental Transformation API
TBA
Model Manipulation Primitives
Model manipulation primitives are implemented by instances of IModelManipulations interface. Currently, two implementations are available:
- SimpleModelManipulations - uses plain EMF API
- ModelManipulationsWithEditingDomain - uses EMF Edit commands on EditingDomain instances
If some transformation needs specific primitives (e.g. transaction support), new instances can introduce extra methods as required.
| Name | Parameters | Description |
|---|---|---|
| create | Resource; EClass | Creates an object with the corresponding EClass type, and puts it into the root of the selected resource |
| createChild | EObject (container); EReference; EClass | Creates an object with the corresponding EClass type, and puts it into the selected reference; the reference must be of containment type |
| addTo | EObject (container); EStructuralFeature; Object | Adds an existing object to the corresponding container with a reference; if using a reference it must *not* be of containment type |
| remove | EObject | Removes the EObject from the model |
| remove | EObject (container); EStructuralFeature; Object | Removes an object from the selected container; when using a containment EReference, also removes it from the resource set |
| remove | EObject (container); EStructuralFeature | Removes all objects from a multivalued feature; when using a containment EReference, also removes them from the resource set |
| set | EObject (container); EStructuralFeature; Object | Sets the value of a single-valued feature |
| move | EObject(s), EObject (new container), EStructuralFeature | Moves elements to a new container, and removes them from an old one. 'Remark': The implementation here is specific, as it relies on features of the index. |
Examples
A (not very well tested) example transformation is available by implementing the Petri net to State Charts case of the Transformation Tool Contest 2013.
- Case description: http://planet-sl.org/community/index.php?option=com_community&view=groups&task=viewgroup&groupid=26&Itemid=387&lang=en
- Implementation: https://github.com/izsob/TTC13-PN2SC-EIQ (look for the branch viatra-api)