[news.eclipse.tools.emf] Re: Does ID property have to be unique in the w

[Ed Merks <Ed.Merks@xxxxxxxxx>]

Alexey,

That's potentially feasible, but not directly supported by EMF.  
Consider that you might have a base class X with two derived classes Y 
and Z each of which has a different ID feature.  Then you might have a 
feature x of type X that refers to Y and Z by ID.  In this case, you'd 
not know if it was a Y or a Z so even Y and Z better have unique IDs.  
So I wouldn't suggest trying to go down your path. 


koloale wrote:
> Of course it XML semantics if id property of xsd:idref type. But when 
> I generate Ecore model from Java classes, my id property has no 
> connection with idref schema type. So is it feasible to deduce type 
> from eReference and search object with given id among only objects 
> wthis correspomding of reference type? Besides, all information for 
> that is available.
>
> Christian W. Damus ÐÐÑÐÑ:
> > Yes.  That is the XML semantics, as well as EMOF.
> >
> > Cheers,
> >
> > Christian
> >
> >
> > koloale wrote:
> > > I have two classes in my Ecore model, A and B, both have id 
> > > property, third  C class has reference to A (non-containment). When 
> > > I assign the same ids A and B objects, and save them in one XML 
> > > resource along with C, the operation executed successfully.
> > > Result xml contains something like:
> > >
> > > <?xml version="1.0" encoding="UTF-8"?>
> > > <root>
> > >   <a id=1/>
> > >   <b id=1/>
> > >   <c a="#1"/>
> > > </root>
> > >
> > > This xml is what I expect. But when loading this xml I get error: 
> > > "Value is not legal", cased by ClassCastException.
> > >
> > > Is any ability to correct this issue? Is it correct that loading 
> > > with id s only works when all ids are unique(in my example a and b 
> > > have to be different)? Why couldn't XMLResource deduce correct type 
> > > of referenced object based on eReference of containing object?
> > >
> > > Thanks in advance,
> > > Alexey