/// <summary>
/// Create new Tracking Iterator for root entity of type {TEntity}
/// </summary>
/// <typeparam name="TEntity">Type of root entity</typeparam>
/// <param name="entity">Root entity</param>
/// <returns>STE Graph Iterator</returns>
internal static ChangeTrackerIterator Create <TEntity>(TEntity entity)
where TEntity : IObjectWithChangeTracker
{
ChangeTrackerIterator iterator = new ChangeTrackerIterator();
iterator.Visit(entity);
return(iterator);
}
/// <summary>
/// This method remove duplications in object graph on the client.
/// <remarks>For more information about duplications problems in Selft Tracking Entities
/// see http://blogs.msdn.com/b/diego/archive/2010/10/06/self-tracking-entities-applychanges-and-duplicate-entities.aspx
/// </remarks>
/// <example>
/// customer.MergeWith(graphWithCustomer,(c1,c2)=>c1.IdCustomer == c2.IdCustomer);
/// </example>
/// </summary>
/// <typeparam name="TEntity">Entity</typeparam>
/// <typeparam name="TGraph">Grago</typeparam>
/// <param name="entity">Type of entity</param>
/// <param name="graph">Type of root graph</param>
/// <param name="keyComparer">the key compararer</param>
/// <returns>returns an instance from the graph with the same key or the original entity </returns>
public static TEntity MergeWith <TEntity, TGraph>(this TEntity entity, TGraph graph, Func <TEntity, TEntity, bool> keyComparer)
where TEntity : class, IObjectWithChangeTracker
where TGraph : class, IObjectWithChangeTracker
{
using (ChangeTrackerIterator iterator = ChangeTrackerIterator.Create(graph))
{
return(iterator.OfType <TEntity>().SingleOrDefault(e => keyComparer(entity, e)) ?? entity);
}
}
/// <summary>
/// Accept all changes in all entities associated with <paramref name="entity"/>
/// </summary>
/// <param name="entity">Root entity</param>
public static void AcceptAllChanges(this IObjectWithChangeTracker entity)
{
using (ChangeTrackerIterator iterator = ChangeTrackerIterator.Create(entity))
iterator.Execute(ste => ste.AcceptChanges());
}
/// <summary>
/// Stop tracking in all entities associated with <paramref name="entity"/>
/// </summary>
/// <param name="entity">Root entity</param>
public static void StopTrackingAll(this IObjectWithChangeTracker entity)
{
using (ChangeTrackerIterator iterator = ChangeTrackerIterator.Create(entity))
iterator.Execute(ste => ste.StopTracking());
}