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How to create an EReference programmatically? [message #1220042]

Mon, 09 December 2013 05:07

Eclipse User

Hi all,

I am trying to programmatically create a connection(an EReference) between two EClass on a GMF-based Editor. (cf. picture - an ERefference bewteen the Student and the Lecture)

I tried using CreateConnectionRequest, codes are as followed:

CreateConnectionRequest createConnectionReques = new CreateConnectionRequest();
		
createConnectionReques.setSourceEditPart(sourceEditPart);
		
createConnectionReques.setTargetEditPart(targetEditPart);
		
Command commandConnection = sourceEditPart.getCommand(createConnectionReques);
		
if(commandConnection.canExecute()){
    commandConnection.execute();
}

but a NullPointerException for the command is thrown, that means the command is not initiated correctly. I really don't know why Sad

.

Could anyone help, how to build the command correctly?

Thanks in advance.

Attachment: Student.png
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Re: How to create an EReference programmatically? [message #1220070 is a reply to message #1220042]

Mon, 09 December 2013 08:13

Eclipse User

Le 09/12/2013 13:58, Xiaoying Hu a écrit :
> Hi all,
>
>
> I am trying to programmatically create a connection(an EReference) between two EClass on a GMF-based Editor. (cf. picture - an ERefference bewteen the Student and the Lecture)
>
> I tried using CreateConnectionRequest, codes are as followed:
>
>
> CreateConnectionRequest createConnectionReques = new CreateConnectionRequest();
>
> createConnectionReques.setSourceEditPart(sourceEditPart);
>
> createConnectionReques.setTargetEditPart(targetEditPart);
>
> Command commandConnection = sourceEditPart.getCommand(createConnectionReques);
>

You don't execute the commands yourself, but must pass through the
command stack (which is responsible for undo/redo behavior):

TransactionalEditingDomain ted = sourceEditPart.getEditingDomain();
ted.getCommandStack().execute(commandConnection);

Re: How to create an EReference programmatically? [message #1220093 is a reply to message #1220070]

Mon, 09 December 2013 11:04

Eclipse User

Hi Pierre-Charles,

thanks for your quick reply.

Quote:

You don't execute the commands yourself, but must pass through the
command stack (which is responsible for undo/redo behavior):

TransactionalEditingDomain ted = sourceEditPart.getEditingDomain();
ted.getCommandStack().execute(commandConnection);

There is a problem here, the execute method is not applicable for a GEF command (org.eclipse.gef.commands.Command), it works only for EMF command(org.eclipse.emf.common.command.Command).

To run the GEF command is the second step, the first step is to get the GEF command, in my case using the code:

Command commandConnection = sourceEditPart.getCommand(createConnectionReques);

This doesn't work. So the question is, how can I get the correct command to run the request?

Any idea will be appreciated. Smile

Re: How to create an EReference programmatically? [message #1692795 is a reply to message #1220093]

Sat, 18 April 2015 17:00

Eclipse User

Hello there,

I encountered the same issue.

I came up with the following method which seems to solve the problem.

public void createAndExecuteConnectionRequestCommand(IElementType type, DiagramEditPart editPart, EditPart source, EditPart target) {
		CreateConnectionViewAndElementRequest request = new CreateConnectionViewAndElementRequest(type, ((IHintedType) type).getSemanticHint(), editPart.getDiagramPreferencesHint());
		Command cmd = CreateConnectionViewAndElementRequest.getCreateCommand(request, 
						source, target);
		System.out.println(cmd.getLabel());
		diagramEditPart.getDiagramEditDomain().getDiagramCommandStack().execute(cmd);
		//hack to refresh visuals and show the connection!
		diagramEditPart.addNotify();
}

Best, Nikos.

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