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Processing an Ecore-Based Model as a Graph [message #1415196]

Tue, 02 September 2014 09:41

Tom Richardson

Messages: 3
Registered: August 2014

Junior Member

Hello,

I currently have a graphml model/muddle and an EOL program which processes this model. However, I would like to (minimally) modify my EOL program to process an Ecore-based version of my model. I am therefore looking to replace the code below with something that would perform the equivalent function but with an Ecore-based model:

var elements = myModel.muddle.elements;
var nodes = elements.select(e|e.type.eClass().name = "MuddleElementType");
var edges = elements.select(e|e.type.eClass().name = "LinkElementType");

for(e in edges)
{
if(e.Target = self && e.Source = x)
{
}
}

for (n in nodes
{
//process
}

Having looked at the Javadoc for EmfModel, I noticed the methods
getAllOfType, getAllOfKind, and allContents. I tried:

var elements = myModel.getAllOfKind("EObject");
var elements = myModel.allContents();

These lines of code only returned the "nodes", that is, the EReferences (edges) were not returned. Furthermore, var edges = myModel.getAllOfKind("EReference") returned zero elements.

Does anyone have any suggestions?

Even if it is possible to obtain a list of all EReferences in a model, is it then possible to obtain the source and target EObjects given an EReference (as shown in the code above)? It would appear to me that it is only possible to determine the target of an EReference from a given source EObject.

Thanks,
Tom

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Re: Processing an Ecore-Based Model as a Graph [message #1415393 is a reply to message #1415196]

Tue, 02 September 2014 17:27

Dimitris Kolovos

Messages: 2163
Registered: July 2009
Location: York, UK

Senior Member

Hi Tom,

When querying a model that conforms to an Ecore metamodel X, you can only use names of EClasses in X as parametes of getAllOf*(). The "EReference" EClass belongs to Ecore.ecore itself (your model -- conforms to --> X.ecore -- conforms to --> Ecore.ecore), so it's two meta-levels up and has no instances in your model. Does this help?

Cheers,
Dimitris

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Re: Processing an Ecore-Based Model as a Graph [message #1415687 is a reply to message #1415393]

Wed, 03 September 2014 11:03

Tom Richardson

Messages: 3
Registered: August 2014

Junior Member

Thanks for the explanation. Is the implication of this then that it is not possible to generate a list\collection of all of the references/edges in my model? So, as an example, if I have an ecore model with 10,000 model elements (nodes) and only two references\links (edges), to find the target element of those two links I would need to iterate through the list of 10,000 model elements calling eCrossReferences() on each node? Clearly, if possible, it would be far more efficient in this case to be able to obtain all edges (2) and iterate through them to find the target nodes.

Thanks,
Tom

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Re: Processing an Ecore-Based Model as a Graph [message #1415701 is a reply to message #1415687]

Wed, 03 September 2014 11:53

Dimitris Kolovos

Messages: 2163
Registered: July 2009
Location: York, UK

Senior Member

Hi Tom,

In EMF, references are not first-class objects. For example, in [1] it is not possible to directly get all the "author" references, but you could get hold of the author of a particular book "b" (b.author), all Writers in the model (Writer.all), or all authors of all books (Book.all.author).

Cheers,
Dimitris

[1] https://www.eclipse.org/epsilon/doc/articles/reflective-emf-tutorial/

[Updated on: Fri, 05 September 2014 10:24]

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