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EMF compare does not work? [message #1777789]

Mon, 04 December 2017 11:14

Eclipse User

Hi,

I have my own EMF model.
In my RCP application, I just created a model 1.
Copy Paste my model 1 to model 2.
Change one simple name property of my Building object in the model 2.

You can see the comparison result:
instead of finding the attribute modification, EMF Compare found an addition and a deletion of the building.
I suppose there is a solution?

Jim

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Re: EMF compare does not work? [message #1777836 is a reply to message #1777789]

Tue, 05 December 2017 03:41

Eclipse User

Hi,

If your model has no identifier, EMF Compare tries to match elements using metrics to compute the "similarity" between your elements. In this case, the two Building objects are too different to match, so EMF Compare doesn't see them as being "the same" and you get an add and delete differences.

You will have to either make sure your models use identifiers or customize the proximity engine for your needs if it doesn't work for you.

Laurent Goubet
Obeo

Re: EMF compare does not work? [message #1777842 is a reply to message #1777836]

Tue, 05 December 2017 04:12

Eclipse User

Thank you Laurent,

I finally used identifiers, but it is not very convenient for me. I would like to customize the comparison.

For the moment I used this:

public class XMIResourceImpl extends org.eclipse.emf.ecore.xmi.impl.XMIResourceImpl {

public XMIResourceImpl() {
}

public XMIResourceImpl(URI uri) {
super(uri);
}

@Override
protected boolean useUUIDs() {
return true;
}
}

My 2 problems:
1. When I copy paste my building from one EMF File to another one, ID are not the same.

2. In some case I don't want to use unique ID.
Imagine my building has a child called BuildingDescription
such BuildingDescription node should be compared whatever the ID.

Maybe I could by myself generate the ID for each class? sometimes it could be generated automatically and sometimes it could be fixed in my code.

But how to achieve?
Do you have doc or?

Re: EMF compare does not work? [message #1777862 is a reply to message #1777842]

Tue, 05 December 2017 08:07

Eclipse User

Finally, if I undertand, there is an ID checkbox that can be used in the model for matching entities in the compare process.

Can you validate that the attribute checked as ID is used?
What about multiple checked ID?
What about subclass with another attribute checked as ID?

But I have another problem now.

When the order is not the same, the differences in the children are not detected.

Example
Quote 1
Building toto, quantity: 1
Beam beam 1, quantity: 1
Building titi

Quote 2
Building titi
Building toto, quantity: 2
Beam beam 1, quantity: 3

The compare result finds:
1. building toto has moved
2. building toto quantity has changed

It does not detect:
beam 1 quantity has changed.

When the order is not changed, then the compare detects correctly changes in the children.
Why?

Re: EMF compare does not work? [message #1779233 is a reply to message #1777862]

Thu, 04 January 2018 04:07

Eclipse User

Hi,

The results you're describing here don't really make sense. The "move" detected by EMF Compare should be "titi" and not "toto". The quantity change should be detected nonetheless unless you have changed he feature filter somehow? Could you provide us with the models you're using so that we could try and check what's happening here?

Laurent Goubet
Obeo

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