Re: [emf-dev] Need help - How to get correct value of a feature ? Why co

[Ed Merks <merks@xxxxxxxxxx>]

Kaniska,

Please use the newsgroup not the mailing
list for questions like this.   I'll only answer any follow up questions
you might have on the newsgroup....

EStructuralFeature.getContainingClass
is supposed to return null for a dynamic feature, but it should not cause
null pointer exceptions.  E.g., this method in BasicEObjectImpl should
properly handle the case that the container class is null:

  public
int
eDerivedStructuralFeatureID(EStructuralFeature eStructuralFeature)
  {
    Class containerClass
= eStructuralFeature.getContainerClass();
    return

      containerClass
== null
? 
        eClass().getFeatureID(eStructuralFeature)
: 
        eDerivedStructuralFeatureID(eStructuralFeature.getFeatureID(),
containerClass);
  }

The exception you mention should only
happen for eObject.eGet(f) only if eObject.eClass().getEAllStructuralFeatures().contains(f)
is false.


Ed Merks/Toronto/IBM@IBMCA
mailto: merks@xxxxxxxxxx
905-413-3265  (t/l 969)

"kaniska" <kaniska@xxxxxxxxxxx>
Sent by: emf-dev-bounces@xxxxxxxxxxx

06/28/2006 12:53 AM

Please respond to
Eclipse Modelling Framework <emf-dev@xxxxxxxxxxx>

To	<emf-dev@xxxxxxxxxxx>
cc
Subject	[emf-dev] Need help - How to get correct value of a feature ? Why        container class is Null ?

EMF Gurus,
 
Dynamically, I get hold of an EPackage
from the Ecore which is discovered during runtime ...
 
EPackage pkg = .......      
     
EClass eClass  = getDriverClass(pkg);
                     
                  
feature = eClass.getEStructuralFeature(propertyName);
 // returns a correct feature 
 
// THE PROBLEM IS container class of feature
is null
// SO I get an exception 'Invalid feature
xxx ..' when I do someEObject.eGet(feature) to extract the value
 
// NOW IF I STATICALLY TRY
TO RETRIEVE THE FEATURE ... its container class is NOT NULL and someEObject.eGet(feature)
.. gives me correct value from xmi file.
EStructuralFeature feature = null;
if
(driverName.equalsIgnoreCase("jms")){
      feature = JMSDriverPackageImpl.eINSTANCE.getJMSDriver().getEStructuralFeature(propertyName);
}
           

//
private EClass getDriverClass() {
   EClass eClass = null;
   for (Iterator i = pkg.getEClassifiers().iterator();
i.hasNext();) {
           
EClassifier eClassifier = (EClassifier) i.next();
           
if (eClassifier instanceof EClass) {
           
            eClass = (EClass) eClassifier;
                     
                  
           
            // Get the eClass whose super
type is Driver
           
            List eSuperTypes = eClass.getESuperTypes();
           
            //
           
            for (Iterator iter = eSuperTypes.iterator();
iter.hasNext();) {
           
                     
  EClass eSuperType = (EClass)iter.next();
           
                     
  //
           
                     
  URI eClassURI = EcoreUtil.getURI(eSuperType);
           
                     
  String eClassURIFragment = eClassURI.fragment();
           
                     
  if (eClassURIFragment.contains("Driver")){
           
                     
              return eClass;
           
                     
  }           
           
            }
           
}                    
              
   }
   return eClass ;
}
           
                     
  
What is the solution to this problem ? How
do I get hold of the feature correctly ?
 
Rgds,
Kaniska_______________________________________________
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