Eclipse Community Forums: EMF Diff/Merge » Cant get the merge to work

Help

Home

Home » Modeling » EMF Diff/Merge » Cant get the merge to work

Show: Today's Messages :: Show Polls :: Message Navigator

Cant get the merge to work [message #1754929]

Fri, 24 February 2017 08:01

Simon BBBBBBB

Messages: 63
Registered: March 2015

Member

Hello there,

i try to merge two of my models. my first model is a normal EMF-Model without references to other ecore-models.

http://imgur.com/WSmfuRo

then i create a new file and try to merge all the differences with the following code:

		LocalDateTime localDateTime = LocalDateTime.now();
		String uhrZeitDatum = "" + localDateTime.getYear() + localDateTime.getMonth() + localDateTime.getDayOfMonth()
				+ localDateTime.getMinute() + localDateTime.getSecond();

		URI referenceURI = URI.createPlatformResourceURI("Test/core.ecore", true);
		URI targetURI = URI.createPlatformResourceURI("Test/" + uhrZeitDatum + ".ecore", true);

		ResourceSet resourceSet = new ResourceSetImpl();
		Resource referenceResource = resourceSet.getResource(referenceURI, true);
		Resource targetResource = resourceSet.createResource(targetURI);
		try {
			targetResource.save(Collections.EMPTY_MAP);
		} catch (IOException e) {
			e.printStackTrace();
		}

		// Instantiate the scopes to compare
		IEditableModelScope referenceScope = new FragmentedModelScope(referenceResource, false);
		IEditableModelScope targetScope = new FragmentedModelScope(targetResource, false);
		IComparison comparison = new EComparisonImpl(targetScope, referenceScope);

		ConfigurableMatchPolicy configurableMatchPolicy = new ConfigurableMatchPolicy();
		ConfigurableDiffPolicy configurableDiffPolicy = new ConfigurableDiffPolicy();
		DefaultMergePolicy defaultMergePolicy = new DefaultMergePolicy();
		comparison.compute(configurableMatchPolicy, configurableDiffPolicy, defaultMergePolicy, null);

		List<IDifference> differences = comparison.getDifferences(Role.REFERENCE);
		comparison.merge(differences, Role.TARGET, true, null);

the result is the following

http://imgur.com/KL2A4Ln

so the supertypes get duplicated. i tryed to change the merge to the following:

		for (IDifference iDifference : differences) {
			if (iDifference instanceof IElementPresence) {
				IElementPresence elementPresenceDifference = (IElementPresence) iDifference;
				elementPresenceDifference.mergeTo(Role.TARGET);
			} else if (iDifference instanceof IReferenceValuePresence) {
				IReferenceValuePresence referenceValuePresence = (IReferenceValuePresence) iDifference;
				referenceValuePresence.mergeTo(Role.TARGET);
			} else if (iDifference instanceof IAttributeValuePresence) {
				IAttributeValuePresence attributeValuePresence = (IAttributeValuePresence) iDifference;
				attributeValuePresence.mergeTo(Role.TARGET);
			}
		}

And the result looks even more strange:

http://imgur.com/74Qfdxf

what am i doing wrong?

[Updated on: Fri, 24 February 2017 08:05]

Report message to a moderator

Re: Cant get the merge to work [message #1755065 is a reply to message #1754929]

Mon, 27 February 2017 18:18

Olivier Constant

Messages: 106
Registered: January 2012

Senior Member

Hello Simon,

You are doing nothing wrong, I could reproduce the issue. It is due to the fact that the behavior of the EClass::eSuperTypes reference is not like other references and must be treated as a specific case. The default comparison method does not handle this specific case because it preferentially targets EMF models (Ecore instance models) over EMF metamodels (Ecore models). Still, I can have a look and see how many such specific cases there are and possibly support them. Are you willing to open a Bugzilla entry? (On the EMF Diff/Merge wiki page, click Bugzilla then click the "File a new bug" link at the bottom of the page.)

Note that it is impossible to provide 100% reliable diff/merge algorithms for EMF metamodels because Ecore elements do not have unique identifiers (unless you provide IDs in another way, via an alternative serialization mechanism for example). You can use alternative, non-ID-based matching algorithms but they will not cover all possible cases, so there are situations where you would have to perform part of the "merge" by editing the model manually.

Report message to a moderator