| [henshin-dev] Failed to execute henshin rules in plug-in developement |
Hi
I’m working on an eclipse plug-in that employ a specific graph transformation to weave certain patterns in a base model. I have programmatically performed this scenario with a JAVA application, but I couldn't do it in an eclipse plug-in project. Using the debugging mode, I got the following exception thrown by the call of the execute() operation.
Particularly, this problem occurs when the graph transformation has to manipulate an attribute value, and I was able to debug the program without errors for a transformation that simply removes a graph node.
java.lang.NullPointerException
at org.eclipse.emf.ecore.util.EcoreUtil.createFromString(EcoreUtil.java:3483)
at org.eclipse.emf.henshin.interpreter.impl.EngineImpl.castValueToDataType(EngineImpl.java:969)
at org.eclipse.emf.henshin.interpreter.impl.EngineImpl.evalAttributeExpression(EngineImpl.java:895)
at org.eclipse.emf.henshin.interpreter.info.VariableInfo.createConstraints(VariableInfo.java:188)
at org.eclipse.emf.henshin.interpreter.info.VariableInfo.createVariables(VariableInfo.java:111)
at org.eclipse.emf.henshin.interpreter.info.VariableInfo.<init>(VariableInfo.java:77)
at org.eclipse.emf.henshin.interpreter.info.RuleInfo.<init>(RuleInfo.java:26)
at org.eclipse.emf.henshin.interpreter.impl.EngineImpl.getRuleInfo(EngineImpl.java:703)
at org.eclipse.emf.henshin.interpreter.impl.EngineImpl$MatchFinder.<init>(EngineImpl.java:305)
at org.eclipse.emf.henshin.interpreter.impl.EngineImpl$MatchGenerator.iterator(EngineImpl.java:251)
at org.eclipse.emf.henshin.interpreter.impl.RuleApplicationImpl.execute(RuleApplicationImpl.java:89)
at org.eclipse.emf.henshin.interpreter.impl.UnitApplicationImpl.executeRule(UnitApplicationImpl.java:175)
at org.eclipse.emf.henshin.interpreter.impl.UnitApplicationImpl.doExecute(UnitApplicationImpl.java:99)
at org.eclipse.emf.henshin.interpreter.impl.UnitApplicationImpl.execute(UnitApplicationImpl.java:89)
at run.Main.execute(Main.java:55)
The code fragment we use to execute the henshin transformation is given here:
HenshinResourceSet resourceSet = new HenshinResourceSet(ResourcePath);
Module module = resourceSet.getModule("unit1.henshin", false);
Resource r = resourceSet.getResource("Test.ecore");
EObject eObject = r.getContents().get(0);
if (eObject instanceof EPackage) {
EPackage p = (EPackage)eObject;
resourceSet.getPackageRegistry().put(p.getNsURI(), p);
}
EGraph graph = new EGraphImpl(resourceSet.getResource("base.xmi"));
Engine engine = new EngineImpl();
UnitApplication app = new UnitApplicationImpl(engine);
app.setEGraph(graph);
app.setUnit(module.getUnit("r1"));
app.execute(null);
Resource rs=resourceSet.getResource("base.xmi");
rs.setModified(true);
rs.getContents().clear();
for(int i=0;i<graph.getRoots().size();i++){
rs.getContents().add(graph.getRoots().get(i));
}
rs.save(null);
Greetings,