AtachOrUpdate extension method for Entity Framework

AttachOrUpdate.cs

public static void AttachOrUpdate<T>(this ObjectSet<T> set, ref T entity) where T : class
{
    ObjectContext context = set.Context;
    string entitySetName = set.EntitySet.Name;

    ObjectStateEntry entry;
    bool isDetached = true;

    if (context.ObjectStateManager.TryGetObjectStateEntry(
            context.CreateEntityKey(entitySetName, entity),
            out entry))
    {
        // Check if it's detached
        isDetached = entry.State == EntityState.Detached;

        // Update the context entry
        entry.ApplyCurrentValues(entity);

        // Set the entity to the discovered entry
        entity = (T)entry.Entity;
    }

    // If no object state entry is found, we must be detached

    // If it's detached, attach it
    if (isDetached)
    {
        set.Attach(entity);
    }
}