[news.eclipse.modeling.gmt] Re: [Epsilon]cloning a model element in EOL

[Dimitrios Kolovos <dskolovos@xxxxxxxxx>]

Hi Kimon,

Say you have

class A {
  attr String a1;
  ref A[*] referenced;
  val A[*] contained[*];
}

To create a copy you should define an operation like this:

operation A createCopy() {
  var n : new A;
  n.a1 := self.a1;
  n.referenced := self.referenced;
  for (contained in self.contained) {
    n.contained.add(contained.createCopy());
  }
  return n;
}

Now if you need to have a generic operation that creates a copy of any 
element, you should use EMF reflection - but in this case it is simpler 
(and safer) to just use the EcoreUtil.copy method mentioned previously.

Cheers,
Dimitris

Kimon Polychroniadis wrote:
> So, let's suppose there is model element A of type TypeOfA , and I wish 
> to create a copy.
> Isn't it possible to create a copy in a more 'manual' manner, with the 
> following the steps below:
>
> 1. create a new element e.g. B := new TypeOfA;
>
> 2. copy A's attributes and feature values one by one (looping through 
> the attributes and features of A, B(.
>
> 3. move B in the container of choice.
>
> However, I am not sure as to how I should reference the atttributes and 
> features of A (and their values).
>
> I realise the solution (if feasible) is a bit 'brute force' but it's a 
> relatively small model I 've got, so I don't think performance would be 
> an issue.
>
> Thanks,
> Kimon
>
> O/H Dimitrios Kolovos έγραψε:
> > Hi Kimon,
> >
> > Thanks for submitting 
> > https://bugs.eclipse.org/bugs/show_bug.cgi?id=246352
> >
> > I'll look into it shortly.
> >
> > Cheers,
> > Dimitris
> >
> > Dimitrios Kolovos wrote:
> > > Hi Kimon,
> > >
> > > There is currently no built-in operation for copying model elements 
> > > in EOL; however this seems to be a useful addition. Could you please 
> > > open a feature request in the bugzilla?
> > >
> > > As a temporary workaround you can use the (static) 
> > > EcoreUtil.copy(EObject eObject) method which does exactly that. 
> > > You'll need to create a new Epsilon tool and add a copy(EObject) 
> > > operation that delegates to the respective operation of the EcoreUtil 
> > > class.
> > >
> > > Cheers,
> > > Dimitris
> > >
> > > Kimon Polychroniadis wrote:
> > > > Hi,
> > > >
> > > > I am trying to copy an element of my model in another container in the
> > > > model. For example I got element A in container C1 and I want to make a
> > > > copy of A (e.g. B) in another container (e.g. C2). So the goal is to
> > > > have A in C1 and B in C2, wiht A and B being identical.
> > > >
> > > > However, I noticed that the ':= ' operator moves the object rather
> > > > copying it. I also thought of using the clone() command, 
> > > > manipulating the element as a Collection, no result. Is there a more 
> > > > rational way of doing this?
> > > >
> > > > Thank you in advance,
> > > > Kimon