emfReflexive

Headline

reflexive Technology:EMF Model to Model transformation

Motivation

This implementation demonstrates Model to Model transformations with Technology:EMF for Language:Java. Contrary to Contribution:emfGenerative, the models properties are accessed and modified by reflexive method calls to the EMF Model itself. The metamodels used in this implementation are given in Language:Ecore, models are in Language:XMI. The implementation uses the Total scenario to show a exogenous model transformation. The Cut scenario shows an endogenous model transformation.

Illustration

The structure of a company can be modeled as a metamodel. By doing so, one can load any company conforming to this metamodel by first loading the metamodel and then loading the actual model:

/* Load metamodel */
Resource companyMetamodel = resourceSet.createResource(URI.createFileURI("Metamodels/Company.ecore"));
companyMetamodel.load(null);
EPackage.Registry.INSTANCE.put("http://www.company.com", companyMetamodel.getContents().get(0));

/* code ommited */

/* Load model */
Resource companySampleModel = resourceSet.createResource(URI.createFileURI("Models/sampleCompany.xmi"));
companySampleModel.load(null);

Then, attributes can be modified using reflexive calls. For example, the Cut operation can be implemented by iterating over all elements of the model, retrieving the value for the salary if the current element is a Employee and then setting the salary attribute for this employee to the half of what was returned earlier:

if( currentModelElement.eClass().getName().equals("Employee") ) {
   EStructuralFeature salaryAttribute = currentModelElement.eClass().getEStructuralFeature("salary");
   double currentSalary = (Double) currentModelElement.eGet(salaryAttribute);
   currentModelElement.eSet(salaryAttribute, currentSalary/2);
}

Architecture

Company.ecore is the implements the data model for Feature:Hierarchical company. It is the metamodel used for the transformation and can be found in the "Metamodels" directory.

The model that holds the actual data is sampleCompany.xmi and can be found in the "Models" directory.

The model sampleCompany holds the data for the Feature:Hierarchical company.

The metamodel Total is used for the Feature:Cut feature.

The actual transformations are implemented in the class RunTransfo.