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A newbie question of EMF transaction [message #1014163]

Mon, 25 February 2013 04:29

Eclipse User

The RecordingCommand is said to support the undo function.

below is the code that makes me confused.

package test;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;
import org.eclipse.emf.transaction.RecordingCommand;
import org.eclipse.emf.transaction.TransactionalCommandStack;
import org.eclipse.emf.transaction.TransactionalEditingDomain;
import org.eclipse.example.library.Book;
import org.eclipse.example.library.BookCategory;
import org.eclipse.example.library.Library;
import org.eclipse.example.library.LibraryFactory;
import org.eclipse.example.library.Writer;

public class TransactionalEditingDomainTest {
public static void main(String[] args) {
LibraryFactory factory = LibraryFactory.eINSTANCE;

final Library library = factory.createLibrary();
final Writer sakop = factory.createWriter();

ResourceSet rset = new ResourceSetImpl();
rset.getResourceFactoryRegistry().getExtensionToFactoryMap()
.put("xmi", new XMIResourceFactoryImpl());
final Resource file1 = rset.createResource(URI.createFileURI("test.xmi"));

TransactionalEditingDomain domain = TransactionalEditingDomain.Factory.INSTANCE
.createEditingDomain(rset);

TransactionalCommandStack stack = (TransactionalCommandStack) domain.getCommandStack();

RecordingCommand command = new RecordingCommand(domain) {

@Override
protected void doExecute() {
file1.getContents().add(library);
library.getWriters().add(sakop);
}

public boolean canUndo(){
return true;
}
};

System.out.println(library.getWriters());
stack.execute(command);
System.out.println(library.getWriters());
stack.undo();
System.out.println(library.getWriters());//still prints the writer list
}
}

I suppose that after undo library.getWriters() should be an empty EList,can sb tell me why?

Thanks

Re: A newbie question of EMF transaction [message #1014286 is a reply to message #1014163]

Mon, 25 February 2013 09:20

Eclipse User

You're not using the editing domain's resource set so it's not listening
to your objects being changed.

On 25/02/2013 10:29 AM, sakop qq wrote:
> The RecordingCommand is said to support the undo function.
>
> below is the code that makes me confused.
>
> package test;
>
>
> import org.eclipse.emf.common.util.URI;
> import org.eclipse.emf.ecore.resource.Resource;
> import org.eclipse.emf.ecore.resource.ResourceSet;
> import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
> import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;
> import org.eclipse.emf.transaction.RecordingCommand;
> import org.eclipse.emf.transaction.TransactionalCommandStack;
> import org.eclipse.emf.transaction.TransactionalEditingDomain;
> import org.eclipse.example.library.Book;
> import org.eclipse.example.library.BookCategory;
> import org.eclipse.example.library.Library;
> import org.eclipse.example.library.LibraryFactory;
> import org.eclipse.example.library.Writer;
>
> public class TransactionalEditingDomainTest {
> public static void main(String[] args) {
> LibraryFactory factory = LibraryFactory.eINSTANCE;
>
> final Library library = factory.createLibrary();
> final Writer sakop = factory.createWriter();
>
> ResourceSet rset = new ResourceSetImpl();
> rset.getResourceFactoryRegistry().getExtensionToFactoryMap()
> .put("xmi", new XMIResourceFactoryImpl());
> final Resource file1 =
> rset.createResource(URI.createFileURI("test.xmi"));
>
> TransactionalEditingDomain domain =
> TransactionalEditingDomain.Factory.INSTANCE
> .createEditingDomain(rset);
>
> TransactionalCommandStack stack = (TransactionalCommandStack)
> domain.getCommandStack();
>
> RecordingCommand command = new RecordingCommand(domain) {
>
> @Override
> protected void doExecute() {
> file1.getContents().add(library);
> library.getWriters().add(sakop);
> }
>
> public boolean canUndo(){
> return true;
> }
> };
>
> System.out.println(library.getWriters());
> stack.execute(command);
> System.out.println(library.getWriters());
> stack.undo();
> System.out.println(library.getWriters());//still prints the
> writer list
> }
> }
>
> I suppose that after undo library.getWriters() should be an empty
> EList,can sb tell me why?
>
> Thanks
>

Re: A newbie question of EMF transaction [message #1014320 is a reply to message #1014286]

Mon, 25 February 2013 10:35

Eclipse User

I made some changes,but still no use

TransactionalEditingDomain domain = TransactionalEditingDomain.Factory.INSTANCE
.createEditingDomain();
ResourceSet rset = domain.getResourceSet();

would you please tell me how to do it ,just a tiny example please,thanks!

Re: A newbie question of EMF transaction [message #1014406 is a reply to message #1014163]

Mon, 25 February 2013 13:56

Eclipse User

Hi,

I'm mildly surprised that you didn't get some kind of exception in
trying to run this stand-alone test application. The Transaction API
wasn't designed to work without the Eclipse framework running; I might
have expected the transaction in which the RecordingCommand executes to
fail to commit because of a problem validating it (the Validation API
also wasn't designed to work without Eclipse).

Can you confirm in the debugger that the top command on the undo stack
is the RecordingCommand? That is, is "stack.undo()" actually undoing
what you think it's undoing?

If so, then what does the ChangeDescription look like that
RecordingCommand.undo() is undoing?

As far as examples are concerned, the EMF Transaction SDK includes
tutorial documentation in the Eclipse Help centre and also an Examples
wizard that installs one or more example projects in your workspace.
These examples are documented in the help.

HTH,

Christian

On 2013-02-25 09:29:52 +0000, sakop qq said:

> The RecordingCommand is said to support the undo function.
>
> below is the code that makes me confused.
>
> package test;
>
>
> import org.eclipse.emf.common.util.URI;
> import org.eclipse.emf.ecore.resource.Resource;
> import org.eclipse.emf.ecore.resource.ResourceSet;
> import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
> import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;
> import org.eclipse.emf.transaction.RecordingCommand;
> import org.eclipse.emf.transaction.TransactionalCommandStack;
> import org.eclipse.emf.transaction.TransactionalEditingDomain;
> import org.eclipse.example.library.Book;
> import org.eclipse.example.library.BookCategory;
> import org.eclipse.example.library.Library;
> import org.eclipse.example.library.LibraryFactory;
> import org.eclipse.example.library.Writer;
>
> public class TransactionalEditingDomainTest {
> public static void main(String[] args) {
> LibraryFactory factory = LibraryFactory.eINSTANCE;
>
> final Library library = factory.createLibrary();
> final Writer sakop = factory.createWriter();
>
> ResourceSet rset = new ResourceSetImpl();
> rset.getResourceFactoryRegistry().getExtensionToFactoryMap()
> .put("xmi", new XMIResourceFactoryImpl());
> final Resource file1 = rset.createResource(URI.createFileURI("test.xmi"));
>
> TransactionalEditingDomain domain =
> TransactionalEditingDomain.Factory.INSTANCE
> .createEditingDomain(rset);
>
> TransactionalCommandStack stack = (TransactionalCommandStack)
> domain.getCommandStack();
>
> RecordingCommand command = new RecordingCommand(domain) {
>
> @Override
> protected void doExecute() {
> file1.getContents().add(library);
> library.getWriters().add(sakop);
> }
>
> public boolean canUndo(){
> return true;
> }
> };
>
> System.out.println(library.getWriters());
> stack.execute(command);
> System.out.println(library.getWriters());
> stack.undo();
> System.out.println(library.getWriters());//still prints the writer list
> }
> }
>
> I suppose that after undo library.getWriters() should be an empty
> EList,can sb tell me why?
>
> Thanks

Re: A newbie question of EMF transaction [message #1014595 is a reply to message #1014406]

Tue, 26 February 2013 00:53

Eclipse User

Yes,an error was thrown saying that the "EvaluationContext.class" is not found,so I added "org.eclipse.core.expressions" to the dependecy list and the error was suppressed

Re: A newbie question of EMF transaction [message #1014800 is a reply to message #1014595]

Tue, 26 February 2013 08:38

Eclipse User

OK, that makes sense.

So, the problem is resolved? Or it still occurs but now there are no
errors in the log?

cW

On 2013-02-26 05:53:06 +0000, sakop qq said:

> Yes,an error was thrown saying that the "EvaluationContext.class" is
> not found,so I added "org.eclipse.core.expressions" to the dependecy
> list and the error was suppressed

Re: A newbie question of EMF transaction [message #1015164 is a reply to message #1014800]

Wed, 27 February 2013 10:45

Eclipse User

In fact, I was trying to do some experiments using TransactionalEditingDomain in graphiti. But I didn't know where to use it,so I quitted.Thanks anyway.

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