/// <summary>
/// Extension method used to attach the specified entity as modified,
/// with the specified original state.
/// </summary>
/// <typeparam name="T">The entity Type</typeparam>
/// <param name="objectSet">The ObjectSet to attach to</param>
/// <param name="current">The current entity state</param>
/// <param name="original">The original entity state</param>
public static void AttachAsModified <T>(this ObjectSet <T> objectSet, T current, T original) where T : class
{
if (objectSet == null)
{
throw new ArgumentNullException("objectSet");
}
if (current == null)
{
throw new ArgumentNullException("current");
}
if (original == null)
{
throw new ArgumentNullException("original");
}
// Attach the entity if it is not already attached, or if it is already
// attached, transition to Modified
EntityState currState = ObjectContextUtilities.GetEntityState(objectSet.Context, current);
if (currState == EntityState.Detached)
{
objectSet.Attach(current);
}
else
{
objectSet.Context.ObjectStateManager.ChangeObjectState(current, EntityState.Modified);
}
ObjectStateEntry stateEntry = ObjectContextUtilities.AttachAsModifiedInternal(current, original, objectSet.Context);
if (stateEntry.State != EntityState.Modified)
{
// Ensure that when we leave this method, the entity is in a
// Modified state. For example, if current and original are the
// same, we still need to force the state transition
objectSet.Context.ObjectStateManager.ChangeObjectState(current, EntityState.Modified);
}
}
/// <summary>
/// Extension method used to attach the specified entity as modified. This overload
/// can be used in cases where the entity has a Timestamp member.
/// </summary>
/// <typeparam name="T">The entity Type</typeparam>
/// <param name="objectSet">The ObjectSet to attach to</param>
/// <param name="entity">The current entity state</param>
public static void AttachAsModified <T>(this ObjectSet <T> objectSet, T entity) where T : class
{
if (objectSet == null)
{
throw new ArgumentNullException("objectSet");
}
if (entity == null)
{
throw new ArgumentNullException("entity");
}
ObjectContext context = objectSet.Context;
EntityState currState = ObjectContextUtilities.GetEntityState(context, entity);
if (currState == EntityState.Detached)
{
// attach the entity
objectSet.Attach(entity);
}
// transition the entity to the modified state
context.ObjectStateManager.ChangeObjectState(entity, EntityState.Modified);
}
