This is how we implement a generic Save() service in WCF for our EF entities. A TT does the work for us. Even though we don't have any problems with it, I hate to assume this is the best approach (even if it might be). You guys seem pretty darn bright and helpful, so I thought I would pose the question:
Is there a better way?
[OperationContract]
public User SaveUser(User entity)
{
bool _IsDeleted = false;
using (DatabaseEntities _Context = new DatabaseEntities())
{
switch (entity.ChangeTracker.State)
{
case ObjectState.Deleted:
//delete
_IsDeleted = true;
_Context.Users.Attach(entity);
_Context.DeleteObject(entity);
break;
default:
//everything else
_Context.Users.ApplyChanges(entity);
break;
}
// now, to the database
try
{
// try to save changes, which may cause a conflict.
_Context.SaveChanges(System.Data.Objects.SaveOptions.None);
}
catch (System.Data.OptimisticConcurrencyException)
{
// resolve the concurrency conflict by refreshing
_Context.Refresh(System.Data.Objects.RefreshMode.ClientWins, entity);
// Save changes.
_Context.SaveChanges();
}
}
// return
if (_IsDeleted)
return null;
entity.AcceptChanges();
return entity;
}
Why are you doing this with Self tracking entities? What was wrong with this:
[OperationContract]
public User SaveUser(User entity)
{
bool isDeleted = false;
using (DatabaseEntities context = new DatabaseEntities())
{
isDeleted = entity.ChangeTracker.State == ObjectState.Deleted;
context.Users.ApplyChanges(entity); // It deletes entities marked for deletion as well
try
{
// no need to postpone accepting changes, they will not be accepted if exception happens
context.SaveChanges();
}
catch (System.Data.OptimisticConcurrencyException)
{
context.Refresh(System.Data.Objects.RefreshMode.ClientWins, entity);
context.SaveChanges();
}
}
return isDeleted ? null : entity;
}