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//---------------------------------------------------------------------
// <copyright file="EntityWithChangeTrackerStrategy.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//---------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Text;
using System.Data.Objects.DataClasses;
using System.Diagnostics;
namespace System.Data.Objects.Internal
{
/// <summary>
/// Implementation of the change tracking strategy for entities that support change trackers.
/// These are typically entities that implement IEntityWithChangeTracker.
/// </summary>
internal sealed class EntityWithChangeTrackerStrategy : IChangeTrackingStrategy
{
private IEntityWithChangeTracker _entity;
/// <summary>
/// Constructs a strategy object that will cause the change tracker to be set onto the
/// given object.
/// </summary>
/// <param name="entity">The object onto which a change tracker will be set</param>
public EntityWithChangeTrackerStrategy(IEntityWithChangeTracker entity)
{
_entity = entity;
}
// See IChangeTrackingStrategy documentation
public void SetChangeTracker(IEntityChangeTracker changeTracker)
{
_entity.SetChangeTracker(changeTracker);
}
// See IChangeTrackingStrategy documentation
public void TakeSnapshot(EntityEntry entry)
{
if (entry != null && entry.RequiresComplexChangeTracking)
{
entry.TakeSnapshot(true);
}
}
// See IChangeTrackingStrategy documentation
public void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value)
{
member.SetValue(target, value);
}
// See IChangeTrackingStrategy documentation
public void UpdateCurrentValueRecord(object value, EntityEntry entry)
{
// Has change tracker, but may or may not be a proxy
bool isProxy = entry.WrappedEntity.IdentityType != _entity.GetType();
entry.UpdateRecordWithoutSetModified(value, entry.CurrentValues);
if (isProxy)
{
entry.DetectChangesInProperties(true); // detect only complex property changes
}
}
}
}
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