[news.eclipse.tools.emf] Re: Attribute dependency validation

[Eric Rizzo <eclipse-news@xxxxxxxxxxxx>]

Ed Merks wrote:
> José,
>
> Comments below.
>
> José Parera wrote:
> > I have a problem when I try to validate an attribute that depends on 
> > another.
> > Let's suppose I have a XSD model in which attribute A of type double 
> > has a valid range of values that depends on the value of another 
> > attribute B, also double. Let's say that the range of values of A is 
> > 0.5*value(B) ... 1.5*value(B). I need a 'live' validation of the 
> > attribute as is done on the generated editor.
> >
> > The generated Validator simply checks the range of A against fixed 
> > values specified using minInclusive and maxInclusive. I wish to modify 
> > the generated validateA (or validateA_Min/Max) method to take account 
> > of the dependency. The trouble is that I don't know how to access the 
> > EObject instance being validated  because the methods are called with 
> > just a double parameter. I thought that the context parameter will be 
> > useful but I couldn't get the instance reference from it.
> The facet constraints are directly constraints on a data type's value 
> and are independent of where those might be used.  You really would want 
> to define a constraint on the complex type itself to define a constraint 
> between the attributes within that complex type.  You could do that with 
> an ecore:constraints annotation on the complex type and would just name 
> the constraints, e.g., ecore:constraints="AProperlyRelatedToB".  This 
> will generate a hook in the XyzValidator and you can specialize that to 
> implement the logic for the constraint.

Ed,
Can you provide any more details or an example of the ecore:constraints 
annotation. I tried to Google it but am frustrated by Google's refusal 
to consider punctuation like : no matter how I try to quote or escape it.

Thanks,
Eric