Tony

// Get EntitySet for the specified entity’s navigation
private static string GetNavigationEntitySet(this ObjectContext context, object entity, string navPropertyName)
{
EntityType entityType = context.MetadataWorkspace
.GetCSpaceEntityType(entity.GetType());

EntityContainer entityContainer = context.MetadataWorkspace
.GetEntityContainer(context.DefaultContainerName, DataSpace.CSpace);

NavigationProperty navProp = entityType.NavigationProperties.Where(n => n.Name == navPropertyName).SingleOrDefault();
string navEndTypeName = navProp.ToEndMember.GetEntityType().Name;
string navEndRelationKeyName = navProp.RelationshipType.RelationshipEndMembers[navEndTypeName].DeclaringType.FullName;

EntitySetBase entitySetNavRelation = entityContainer
.BaseEntitySets.Where(bes => bes.ElementType.FullName == navEndRelationKeyName).SingleOrDefault();

RelationshipSet relationshipSet = null;
AssociationSet associationSet = null;
if (entityContainer.TryGetRelationshipSetByName(entitySetNavRelation.Name, true, out relationshipSet))
{
associationSet = relationshipSet as AssociationSet;
}
if (associationSet == null)
{
throw new ArgumentException(String.Format(“Unable to find a CSpace AssociationSet for type {0} given navigation name {1}”, entityType.Name, navPropertyName));
}

AssociationSetEnd associationSetEnd = associationSet.AssociationSetEnds.Where(ase => ase.Name == navEndTypeName).SingleOrDefault();
string navEndEntitySetName = associationSetEnd.EntitySet.Name;

return navEndEntitySetName;
}

However, I’m unable to download the source code associated with this blogpost. Could you please check if the downloads are still working? I’d like to take a look at the T4 templates, but can’t find them anywhere.

Thanks for sharing with the community!

I appreciate the great post.

I was hoping you could provide a little background on the decision to use the navigation property name as the entityset when attaching to the context. I’m new to EF and I’m looking at how I could modify the solution to support entity per type where the navigation property name is not used as the entityset but is instead deterministically found. I thought that getting the dependent (FK) of the navigation would allow me to then determine its base type and it turn get the base type’s entityset (and do so for each child in the graph).

I updated the service template to code generate the base type inheritance with the trackable interface.

For example, I have a People entityset of type Person. When modifing an object of base type Person I would like to attach it to the correct entityset (People).

e.g. context.AttachTo(“People”, objectWithPersonBaseType);

Any pointers or gotchas would be appreciated.
Thanks.
Morgan

Cheers,
Tony

Are all of the open items in the ReadMe.txt file addressed in the latest version?

Client T4 TODO:
- Include assoc fixup code
- Perform cascading deletes
- Handle change to Tracking property
- Set foreign keys on added child entities
- Implement GetChanges method

Also, I am getting errors when I try to execute your templates in my projects:

“Could not find file ‘c:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\MyModel.edmx’”

It seems to be looking for the model in the wrong directory. Any ideas? Happy to take this discussion off-line if you like.

- Alan