/// <summary>
/// <para>Merge changes from a one or more updated entities into original entities.</para>
/// <para>First call GetChanges on the change tracker, passing changes to a service update operation.</para>
/// <para>Then call MergeChanges, passing one or more updated entities from the service update operation.</para>
/// <para>Properties on original entities will be set to those from updated entities.</para>
/// <code>
/// // Usage:
/// // Start change-tracking originalEntity (new or retrieved from service)
/// var changeTracker = new ChangeTrackingCollection(originalEntity);
///
/// // Make changes to originalEntity, including reference and child entities
///
/// // Get changes
/// var changedEntity = changeTracker.GetChanges().SingleOrDefault();
///
/// // Pass changes to service update operation
/// var updatedEntity = service.Update(changedEntity);
///
/// // Merge updates from updated entity back into the original entity
/// changeTracker.MergeChanges(updatedEntity);
/// </code>
/// </summary>
/// <typeparam name="TEntity">Trackable entity type</typeparam>
/// <param name="changeTracker">Change tracker used to track changes on original entities</param>
/// <param name="updatedItems">One or more entities updated with changes from a service update operation</param>
/// <exception cref="ArgumentException">
/// <para>Entity must implement IEquatable(TEntity)</para>
/// <para>Update Trackable Entities Visual Studio Extension to v 2.0 or later, then re-generate client entities.</para>
/// </exception>
public static void MergeChanges <TEntity>(this ChangeTrackingCollection <TEntity> changeTracker,
params TEntity[] updatedItems)
where TEntity : class, ITrackable, IIdentifiable, INotifyPropertyChanged
{
// Check for no items
if (updatedItems == null)
{
throw new ArgumentNullException("updatedItems");
}
// Recursively set tracking state for child collections
changeTracker.MergeChanges(updatedItems, null);
}
public static ChangeTrackingCollection <TEntity> GetChanges(ChangeTrackingCollection <TEntity> source)
{
var helper = new CloneChangesHelper();
var wrapper = new Wrapper()
{
Result = source
};
// Inspect the graph and collect entityChangedInfos
helper.GetChanges(Enumerable.Repeat(wrapper, 1)).ToList();
// Clone only changed items
var clone = TrackableExtensions.CloneObject(wrapper, helper);
return(clone.Result);
}
