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Set reference dynamically [message #1809564]

Thu, 18 July 2019 09:33

Kai S.

Messages: 20
Registered: June 2019

Junior Member

Hey,

I am trying to set a reference feature after loading in an .ecore-model at runtime. Let's say my ecore-model defines 2 classes "Source" and "Target" and a reference "required" from "Source" to "Target" with the cardinality "0..*". So in the generated model code you have a member variable like this:

protected EList<Target> required;

Now, I create instance-objects dynamically of the classes "Source" and "Target". Lets say, both have an attribute "name" that I also set. So this would look like this:

//res here is the resource I loaded in dynamically from a given .ecore-file
EPackage metapackage = (EPackage) res.getContents().get(0);
EFactory metafactory = metapackage.getEFactoryInstance();

//creating an instance of SourceClass
EClass sourceClass = (EClass) metapackage.getEClassifier("SourceClass");
EAttribute sourceNameAttr = (EAttribute) sourceClass.getEStructuralFeature("name");
EObject sourceClassInstance = metafactory.create(sourceClass);
sourceClassInstance.eSet(sourceNameAttr, "Some beautiful source name...");

//creating an instance of TargetClass
EClass targetClass = (EClass) metapackage.getEClassifier("TargetClass");
EAttribute targetNameAttr = (EAttribute) targetClass.getEStructuralFeature("name");
EObject targetClassInstance = metafactory.create(targetClass);
targetClassInstance.eSet(targetNameAttr, "Some beautiful target name...");

Now, how do I set the "required"-reference from the sourceClassInstance to point to targetClassInstance? When looking at the documentation of EReference I do not find any setter-method to it, so I tried something like the following:

for(EReference r: sourceClass.getEAllReferences()) {
	if(r.getName().contentEquals("required")) {
		sourceClassInstance.eSet(r, targetClassInstance);
	}
}

But this does not seem to work.

Does anyone know how I would go about setting the "required"-reference to point to the targetClassInstance? Since this a 0..*-reference and thus implemented as a list, do I somehow need to retrieve the list and then call add() on it?

Thanks a lot!

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Re: Set reference dynamically [message #1809566 is a reply to message #1809564]

Thu, 18 July 2019 09:59

Kai S.

Messages: 20
Registered: June 2019

Junior Member

I nearly had it: I just realized that I just need to set a List of the required types via the eSet-method since the reference is a multi-value one :)

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Re: Set reference dynamically [message #1809574 is a reply to message #1809566]

Thu, 18 July 2019 11:18

Kai S.

Messages: 20
Registered: June 2019

Junior Member

I have another closely related question though, maybe someone can help me out with that:
How do I dynamically get the type of the reference-target? So how would I get to know that the EList required holds element of type "Target"? I guess I would need some kind of method on the EReference to hand me the target type like EReference.getTarget() or similar.

Is there a way to determine this at runtime?

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