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From "Amita Vadhavkar" <amita.vadhav...@gmail.com>
Subject Re: [SDO] questions about support for Enumeration facet
Date Fri, 14 Dec 2007 10:51:52 GMT
Tried to do little more analysis to see what is the way to reach
ExtendedMetadata from DataObjectUtil. Please see the findings below.

DataObjectUtil.getMetaObjectInstanceProperty(EModelElement, Property) can be
reached from
AttributeImpl(EAttributeImpl), ClassImpl(EClassImpl),
DataTypeImpl(EDataTypeImpl), ReferenceImpl(EReferenceImpl).

Below is the inheritance for EAttributeImpl -
java.lang.Object
  extended by org.eclipse.emf.common.notify.impl.BasicNotifierImpl
      extended by org.eclipse.emf.ecore.impl.BasicEObjectImpl
          extended by org.eclipse.emf.ecore.impl.EObjectImpl
              extended by org.eclipse.emf.ecore.impl.FlatEObjectImpl
                  extended by org.eclipse.emf.ecore.impl.EModelElementImpl**
                      extended by
org.eclipse.emf.ecore.impl.ENamedElementImpl
                          extended by
org.eclipse.emf.ecore.impl.ETypedElementImpl
                              extended by
org.eclipse.emf.ecore.impl.EStructuralFeatureImpl
                                  extended by
org.eclipse.emf.ecore.impl.EAttributeImpl

Below is the inheritance for EClassImpl -
java.lang.Object
  extended by org.eclipse.emf.common.notify.impl.BasicNotifierImpl
      extended by org.eclipse.emf.ecore.impl.BasicEObjectImpl
          extended by org.eclipse.emf.ecore.impl.EObjectImpl
              extended by org.eclipse.emf.ecore.impl.FlatEObjectImpl
                  extended by org.eclipse.emf.ecore.impl.EModelElementImpl**
                      extended by
org.eclipse.emf.ecore.impl.ENamedElementImpl
                          extended by
org.eclipse.emf.ecore.impl.EClassifierImpl
                              extended by
org.eclipse.emf.ecore.impl.EClassImpl

Below is the inheritance for EDataTypeImpl -
java.lang.Object
  extended by org.eclipse.emf.common.notify.impl.BasicNotifierImpl
      extended by org.eclipse.emf.ecore.impl.BasicEObjectImpl
          extended by org.eclipse.emf.ecore.impl.EObjectImpl
              extended by org.eclipse.emf.ecore.impl.FlatEObjectImpl
                  extended by org.eclipse.emf.ecore.impl.EModelElementImpl**
                      extended by
org.eclipse.emf.ecore.impl.ENamedElementImpl
                          extended by
org.eclipse.emf.ecore.impl.EClassifierImpl****
                              extended by
org.eclipse.emf.ecore.impl.EDataTypeImpl****

Below is the inheritance for EReferenceImpl -
java.lang.Object
  extended by org.eclipse.emf.common.notify.impl.BasicNotifierImpl
      extended by org.eclipse.emf.ecore.impl.BasicEObjectImpl
          extended by org.eclipse.emf.ecore.impl.EObjectImpl
              extended by org.eclipse.emf.ecore.impl.FlatEObjectImpl
                  extended by org.eclipse.emf.ecore.impl.EModelElementImpl**
                      extended by
org.eclipse.emf.ecore.impl.ENamedElementImpl
                          extended by
org.eclipse.emf.ecore.impl.ETypedElementImpl
                              extended by
org.eclipse.emf.ecore.impl.EStructuralFeatureImpl
                                  extended by
org.eclipse.emf.ecore.impl.EReferenceImpl

In this heirarchy,  DataObjectUtil.getMetaObjectInstanceProperty() sticks to
EModelElementImpl as is it common in all these 4 cases.
But in case of EDataTypeImpl there is further hierarchy which is useful when
it comes to facets - which is EClassifierImpl.
EClassifierImpl has getExtendedMetaData() returning
BasicExtendedMetaData.EClassifierExtendedMetaData. This one has all the
methods
for getting different facet informations like - java.util.List<
java.lang.String> getEnumerationFacet() , int     getMinLengthFacet()
and so on.

So a way out to get the enum facet value as a list can be - in
DataObjectUtil.getMetaObjectInstanceProperty() - do as below -

  if(metaObject instanceof EDataTypeImpl/EClassifierImpl){
      if(property.getName().equals("enumeration")) {
          List enumVals =
((EDataTypeImpl)metaObject).getExtendedMetaData().getEnumerationFacet();
          return enumVals;
      }
  }

Same can be the way to get value of "getPatternFacet() as this is the only
other facet which returns a list" (ref
emfBasicExtendedMetaData.EClassifierExtendedMetaData).

For all other facets as they return a single value, the current SDO code may
be enough {OR for all facets on EDataTypeImpl, we can
reach ((EDataTypeImpl)metaObject).getExtendedMetaData() and call patricular
getFacet methods, not sure if this is required - suggestions?}

DataObjectUtil.getMetaObjectInstanceProperties() can remain unchanged.

With the above change in DataObjectUtil.getMetaObjectInstanceProperty(), we
can add a new method in SDOUtil -

public static List<String> getEnumerationFacet(Type type) {
   Property enumProperty = getInstanceProperty(type, "enumeration");
   return DataObjectUtil.getMetaObjectInstanceProperty(type, enumProperty);
}

This way for a DataTypeImpl enum facet values will come out as a List.
Please give suggestions.
I can open another JIRA and fix patternFacet too in same way.

Regards,
Amita

On Dec 12, 2007 3:40 PM, kelvin goodson <kelvin@thegoodsons.org.uk> wrote:

> By the way, until the wiki has been used to update the websitre then the
> FAQ
> can be seen at
>
> http://cwiki.apache.org/confluence/display/TUSCANY/Tuscany+SDO+Java+-+FAQ
>
> Kelvin.
>
> On 12/12/2007, kelvin goodson <kelvin@thegoodsons.org.uk> wrote:
> >
> > It occurred to me that there's a bit of a knack to debugging into EMF
> > code,  so I just wrote an FAQ to describe how to do this.  Comments are
> > welcome on its clarity or accuracy.
> >
> > Regards, Kelvin.
> >
> > On 11/12/2007, kelvin goodson <kelvin@thegoodsons.org.uk> wrote:
> > >
> > > Amita,
> > >
> > > It feels like option 1 is the easy way to do things, and option 2 is
> the
> > > right way given the introduction of instance properties on metadata
> provided
> > > for this purpose (but doesn't currently work).
> > >
> > > Here's the results of my digging around.  Let's start with what I
> found
> > > last since it might prove to be the answer.  It seems highly likely to
> be
> > > so,  but there is more thinking to be done.  So after quite a bit of
> digging
> > > to see how things are handled in EMF I saw the TODO in DataObjectUtil
> ....
> > >
> > >   public static Object getMetaObjectInstanceProperty(EModelElement
> > > metaObject, Property property)
> > >   {
> > >     String value = EcoreUtil.getAnnotation(metaObject,
> > > property.getContainingType().getURI(), property.getName ());
> > >     //TODO if (property.isMany()) ... // create list of values from
> from
> > > string
> > >     return SDOUtil.createFromString(property.getType(), value);
> > >   }
> > >
> > > So there's a couple of things I haven't got my head round yet that
> > > perhaps you could take a look at since I must divert my attention for
> a
> > > while.  The first is that the instance Property for the Type's
> enumeration
> > > is isMany = false.  So even if we handled the TODO we wouldn't get the
> > > desired result.  The second is that we must ensure a generic string
> > > tokenizer here,  but I'm not yet confident that the tokenizing that we
> want
> > > to satisfy the current issue would be the same for all Properties.
>  What I
> > > mean by this is that for the example you give,  it starts with the
> separator
> > > "space" indicating that the first literal that should be returned from
> > > tokenizing is the empty string.  Would this be true for all Property
> values,
> > > or is it the case that sometimes we would consider trimming leading
> white
> > > space?
> > >
> > > I had been going down a track of investigating storage and retrieval
> of
> > > the enumeration facets inside EMF,  which may yet prove to be the way
> to fix
> > > this issue.  The facets seem to be stored in two ways.  Once as an
> > > annotation on the metadata artifact directly, in concatenated string
> form,
> > > and once as a vector on the extended metadata associated with the
> eDataType
> > > (See setEnumerationFacet(EDataType,List) of BasicExtendedMetaData.
>  The bulk
> > > of code in setEnumerationFacet is devoted to concatenating the string
> > > literals and hanging the annotation on the eDataType (Type),  but the
> last
> > > line then squirrels the original input vector of enumerations away on
> the
> > > extended metadata.
> > >
> > > Now there is a basicGetEnumerationFacet method on the nested class
> > > EDataTypeExtendedMetaDataImpl,  which is contained in
> BasicExtendedMetaData
> > > which has all the reverse logic for unpacking the vector of
> enumerations
> > > from the concatenated string,  but it never gets called in the
> scenario you
> > > described.  Given the piece of code I included above, that wouldn't
> work
> > > anyway, given the EcoreUtil .getAnnotation returns a single String.
> > >
> > > I don't have a solution yet,  but I'll think on it.  Any suggestions
> you
> > > may have are welcome.
> > >
> > > Regards, Kelvin.
> > >
> > >
> > >
> > >
> > >
> > > On 11/12/2007, Amita Vadhavkar <amita.vadhavkar@gmail.com> wrote:
> > > >
> > > > Hi,
> > > > I tried TUSCANY-1360 related to enumeration facet. Below is the
> > > > summary of
> > > > what was
> > > > discussed so far and a few questions.
> > > >
> -------------------------------------------------------------------------------------------------------------------------------------
> > > >
> > > > 1) One way to do this is -
> > > > public static List<String> getEnumerationFacet(Type type) {
> > > >     return ExtendedMetaData.INSTANCE.getEnumerationFacet
> > > > ((EDataType)type);
> > > > }
> > > >
> > > > which works very straight forward and gives a list of enums.
> > > >
> > > >
> -------------------------------------------------------------------------------------------------------------------------------------
> > > > 2) Another way is -
> > > > Do type.getInstanceProperties() and find the Property called
> > > > "enumeration".
> > > >
> > > > Where, getInstanceProperties() calls
> > > > DataObjectUtil.getMetaObjectInstanceProperties(EModelElement
> > > > metaObject)
> > > > in which for the given metaObject its annotations and details of
> each
> > > > annotations are traversed. Each
> > > > Annotation Detail is mapped to EStringToStringMapEntryImpl entry
> like
> > > > below
> > > > -
> > > >
> > > > EStringToStringMapEntryImpl entry =
> > > > (EStringToStringMapEntryImpl)iter.next();   //iter is Iterator over
> > > > current
> > > > Annotation's Details
> > > > String propertyName = entry.getTypedKey();
> > > >
> > > > Property globalProperty = getGlobalProperty(hc, propertyURI,
> > > > propertyName);
> > > > if (globalProperty != null)
> > > > {
> > > >    result.add(globalProperty);
> > > > }
> > > >
> > > > Result is a UniqueEList which is returned at the end.
> > > >
> > > > Here, when entry.getTypedKey() is "enumeration", entry.getTypedValue
> ()
> > > > gives
> > > > a String having space separated enums
> > > >
> > > > e.g. for
> > > > <simpleType name="ExampleRating">
> > > >     <restriction base="string">
> > > >         <enumeration value=""/>
> > > >         <enumeration value="Good"/>
> > > >         <enumeration value="Bad"/>
> > > >     </restriction>
> > > > </simpleType>
> > > >
> > > > it gives,"   Good Bad"
> > > >
> > > > As we see in Property globalProperty = getGlobalProperty(hc,
> > > > propertyURI,
> > > > propertyName); the TypedKey information is
> > > > used when forming Property with name "enumeration", but the
> TypedValue
> > > > information is not stored in the Property.
> > > > Same thing will be applicable for other facets like MinLenght,
> > > > MaxExclusive....
> > > >
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> > > >
> > > > Questions:
> > > >
> > > > Thus, the question I have is, in case of following 2), what will be
> > > > the way
> > > > to preserve the mapping (key-value)
> > > > information available about facets from EMF in the formed Property?
> > > > And what
> > > > will be better approach for TUSCANY-1360
> > > > and as such for any other facets?
> > > >
> > > > Regards,
> > > > Amita
> > > >
> > >
> > >
> >
>

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