From 9938cb7a73af2adb648b8fbdd782a5d821006a87 Mon Sep 17 00:00:00 2001
From: luboshl <github@hlsoft.cz>
Date: Fri, 22 Jan 2016 01:27:00 +0100
Subject: [PATCH] Added feature: State interceptors with fluent API. - Allows
 user to intercept DbContext.ApplyChanges in order to specify the EntityState
 which should be applied to one or more entities. - Resolves issue #106.

---
 ...bleEntities.Client.Tests.Extensions.csproj |  26 +-
 .../packages.config                           |  11 +-
 .../TrackableEntities.Client.Tests.csproj     |  26 +-
 .../packages.config                           |  11 +-
 .../NorthwindDbContextTests.cs                |  23 +-
 .../StateChangeInterceptorTests.cs            | 815 ++++++++++++++++++
 .../StateInterceptorTests.cs                  | 105 +++
 .../TrackableEntities.EF.5.Tests.csproj       |  24 +-
 .../packages.config                           |  11 +-
 .../TrackableEntities.EF.6.Tests.csproj       |  32 +-
 .../packages.config                           |  11 +-
 Source/TrackableEntities.EF.5/Constants.cs    |   3 +
 .../DbContextExtensions.cs                    | 189 +++-
 .../RelationshipNotDeterminedException.cs     |  21 +
 .../Exceptions/TrackableEntitiesException.cs  |  40 +
 .../IStateInterceptor.cs                      |  26 +
 .../InterceptorExtensions.cs                  |  69 ++
 .../TrackableEntities.EF.5/InterceptorPool.cs |  24 +
 .../RelationshipType.cs                       |  21 +
 .../StateChangeInterceptor.cs                 |  42 +
 .../TrackableEntities.EF.5.csproj             |   7 +
 .../TrackableEntities.EF.6.csproj             |  21 +
 Source/TrackableEntities.sln.DotSettings      |  11 -
 23 files changed, 1447 insertions(+), 122 deletions(-)
 create mode 100644 Source/Tests/TrackableEntities.EF.5.Tests/StateChangeInterceptorTests.cs
 create mode 100644 Source/Tests/TrackableEntities.EF.5.Tests/StateInterceptorTests.cs
 create mode 100644 Source/TrackableEntities.EF.5/Exceptions/RelationshipNotDeterminedException.cs
 create mode 100644 Source/TrackableEntities.EF.5/Exceptions/TrackableEntitiesException.cs
 create mode 100644 Source/TrackableEntities.EF.5/IStateInterceptor.cs
 create mode 100644 Source/TrackableEntities.EF.5/InterceptorExtensions.cs
 create mode 100644 Source/TrackableEntities.EF.5/InterceptorPool.cs
 create mode 100644 Source/TrackableEntities.EF.5/RelationshipType.cs
 create mode 100644 Source/TrackableEntities.EF.5/StateChangeInterceptor.cs
 delete mode 100644 Source/TrackableEntities.sln.DotSettings

diff --git a/Source/Tests/TrackableEntities.Client.Tests.Extensions/TrackableEntities.Client.Tests.Extensions.csproj b/Source/Tests/TrackableEntities.Client.Tests.Extensions/TrackableEntities.Client.Tests.Extensions.csproj
index dda0a2eb..b311b584 100644
--- a/Source/Tests/TrackableEntities.Client.Tests.Extensions/TrackableEntities.Client.Tests.Extensions.csproj
+++ b/Source/Tests/TrackableEntities.Client.Tests.Extensions/TrackableEntities.Client.Tests.Extensions.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props" Condition="Exists('..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props')" />
+  <Import Project="..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
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@@ -15,6 +14,8 @@
     <FileAlignment>512</FileAlignment>
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -50,12 +51,16 @@
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       <Private>True</Private>
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-    <Reference Include="xunit.assert, Version=2.0.0.2929, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\xunit.assert.2.0.0\lib\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.assert.dll</HintPath>
+    <Reference Include="xunit.assert, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.assert.2.1.0\lib\dotnet\xunit.assert.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="xunit.core, Version=2.0.0.2929, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\xunit.extensibility.core.2.0.0\lib\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.dll</HintPath>
+    <Reference Include="xunit.core, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.extensibility.core.2.1.0\lib\dotnet\xunit.core.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="xunit.execution.desktop, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.extensibility.execution.2.1.0\lib\net45\xunit.execution.desktop.dll</HintPath>
       <Private>True</Private>
     </Reference>
   </ItemGroup>
@@ -65,7 +70,9 @@
     <Compile Include="TrackableExtensionsTests.cs" />
   </ItemGroup>
   <ItemGroup>
-    <None Include="packages.config" />
+    <None Include="packages.config">
+      <SubType>Designer</SubType>
+    </None>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\TrackableEntities.Client.Tests.Entities\TrackableEntities.Client.Tests.Entities.csproj">
@@ -92,10 +99,9 @@
   <Import Project="$(SolutionDir)\.nuget\nuget.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
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+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
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+    <Error Condition="!Exists('..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
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diff --git a/Source/Tests/TrackableEntities.Client.Tests.Extensions/packages.config b/Source/Tests/TrackableEntities.Client.Tests.Extensions/packages.config
index 3fcb85d1..cf452a40 100644
--- a/Source/Tests/TrackableEntities.Client.Tests.Extensions/packages.config
+++ b/Source/Tests/TrackableEntities.Client.Tests.Extensions/packages.config
@@ -1,10 +1,11 @@
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 <packages>
   <package id="Newtonsoft.Json" version="6.0.8" targetFramework="net45" />
-  <package id="xunit" version="2.0.0" targetFramework="net45" />
+  <package id="xunit" version="2.1.0" targetFramework="net45" />
   <package id="xunit.abstractions" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.assert" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.core" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.extensibility.core" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.runner.visualstudio" version="2.0.0" targetFramework="net45" />
+  <package id="xunit.assert" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.execution" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.runner.visualstudio" version="2.1.0" targetFramework="net45" />
 </packages>
\ No newline at end of file
diff --git a/Source/Tests/TrackableEntities.Client.Tests/TrackableEntities.Client.Tests.csproj b/Source/Tests/TrackableEntities.Client.Tests/TrackableEntities.Client.Tests.csproj
index 627f3025..bf3ce75f 100644
--- a/Source/Tests/TrackableEntities.Client.Tests/TrackableEntities.Client.Tests.csproj
+++ b/Source/Tests/TrackableEntities.Client.Tests/TrackableEntities.Client.Tests.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
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-  <Import Project="..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props" Condition="Exists('..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props')" />
+  <Import Project="..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
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@@ -15,6 +14,8 @@
     <FileAlignment>512</FileAlignment>
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
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@@ -56,12 +57,16 @@
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-      <HintPath>..\..\packages\xunit.assert.2.0.0\lib\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.assert.dll</HintPath>
+    <Reference Include="xunit.assert, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.assert.2.1.0\lib\dotnet\xunit.assert.dll</HintPath>
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-    <Reference Include="xunit.core, Version=2.0.0.2929, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
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+    <Reference Include="xunit.core, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.extensibility.core.2.1.0\lib\dotnet\xunit.core.dll</HintPath>
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@@ -71,7 +76,9 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>
-    <None Include="packages.config" />
+    <None Include="packages.config">
+      <SubType>Designer</SubType>
+    </None>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\TrackableEntities.Client\TrackableEntities.Client.csproj">
@@ -98,10 +105,9 @@
   <Import Project="$(SolutionDir)\.nuget\nuget.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
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        Other similar extension points exist, see Microsoft.Common.targets.
diff --git a/Source/Tests/TrackableEntities.Client.Tests/packages.config b/Source/Tests/TrackableEntities.Client.Tests/packages.config
index 3fcb85d1..cf452a40 100644
--- a/Source/Tests/TrackableEntities.Client.Tests/packages.config
+++ b/Source/Tests/TrackableEntities.Client.Tests/packages.config
@@ -1,10 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Newtonsoft.Json" version="6.0.8" targetFramework="net45" />
-  <package id="xunit" version="2.0.0" targetFramework="net45" />
+  <package id="xunit" version="2.1.0" targetFramework="net45" />
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-  <package id="xunit.assert" version="2.0.0" targetFramework="net45" />
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-  <package id="xunit.extensibility.core" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.runner.visualstudio" version="2.0.0" targetFramework="net45" />
+  <package id="xunit.assert" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.execution" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.runner.visualstudio" version="2.1.0" targetFramework="net45" />
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diff --git a/Source/Tests/TrackableEntities.EF.5.Tests/NorthwindDbContextTests.cs b/Source/Tests/TrackableEntities.EF.5.Tests/NorthwindDbContextTests.cs
index d72d23a4..a72e0a37 100644
--- a/Source/Tests/TrackableEntities.EF.5.Tests/NorthwindDbContextTests.cs
+++ b/Source/Tests/TrackableEntities.EF.5.Tests/NorthwindDbContextTests.cs
@@ -1,19 +1,18 @@
 using System;
 using System.Collections.Generic;
-using System.Data;
-using System.Data.Entity;
-using System.Diagnostics;
-using System.Linq;
 using Xunit;
 #if EF_6
 using TrackableEntities.EF6;
+using System.Data.Entity;
 #else
 using TrackableEntities.EF5;
+using System.Data;
 #endif
 using TrackableEntities.EF.Tests;
 using TrackableEntities.EF.Tests.Mocks;
 using TrackableEntities.EF.Tests.NorthwindModels;
 
+// ReSharper disable CheckNamespace
 #if EF_6
 namespace TrackableEntities.EF6.Tests
 #else
@@ -22,7 +21,8 @@ namespace TrackableEntities.EF5.Tests
 {
 	public class NorthwindDbContextTests
 	{
-		const CreateDbOptions CreateNorthwindDbOptions = CreateDbOptions.DropCreateDatabaseIfModelChanges;
+        // ReSharper disable once InconsistentNaming
+        const CreateDbOptions CreateNorthwindDbOptions = CreateDbOptions.DropCreateDatabaseIfModelChanges;
 
 		#region Product: Single Entity
 
@@ -1623,7 +1623,8 @@ public void Apply_Changes_Should_Mark_Added_Customer_As_Modified_And_Deleted_Set
 			Assert.NotNull(customer.CustomerSetting);
 		}
 
-		[Fact]
+        // TODO: remove (replaced by Apply_Changes_With_State_Interceptor_Should_One_To_One_Entities_State)
+        [Fact]
 		public void Apply_Changes_Should_Mark_Deleted_Customer_As_Deleted_And_Unchanged_Setting_As_Deleted()
 		{
 			// NOTE: CustomerSetting will be set to null because customer is deleted.
@@ -1645,7 +1646,8 @@ public void Apply_Changes_Should_Mark_Deleted_Customer_As_Deleted_And_Unchanged_
 			Assert.Null(customer.CustomerSetting);
 		}
 
-		[Fact]
+        // TODO: remove (replaced by Apply_Changes_With_State_Interceptor_Should_One_To_One_Entities_State)
+        [Fact]
 		public void Apply_Changes_Should_Mark_Deleted_Customer_As_Deleted_And_Added_Setting_As_Deleted()
 		{
 			// NOTE: CustomerSetting will be set to null because customer is deleted.
@@ -1667,7 +1669,8 @@ public void Apply_Changes_Should_Mark_Deleted_Customer_As_Deleted_And_Added_Sett
 			Assert.Null(customer.CustomerSetting);
 		}
 
-		[Fact]
+        // TODO: remove (replaced by Apply_Changes_With_State_Interceptor_Should_One_To_One_Entities_State)
+        [Fact]
 		public void Apply_Changes_Should_Mark_Deleted_Customer_As_Deleted_And_Deleted_Setting_As_Deleted()
 		{
 			// NOTE: CustomerSetting will be set to null because customer is deleted.
@@ -1925,6 +1928,6 @@ public void Apply_Changes_Should_Mark_Deleted_Order_As_Deleted_And_Deleted_Custo
 			Assert.Null(order.CustomerId);
 		}
 
-		#endregion
-	}
+        #endregion        
+    }
 }
diff --git a/Source/Tests/TrackableEntities.EF.5.Tests/StateChangeInterceptorTests.cs b/Source/Tests/TrackableEntities.EF.5.Tests/StateChangeInterceptorTests.cs
new file mode 100644
index 00000000..5e185b8c
--- /dev/null
+++ b/Source/Tests/TrackableEntities.EF.5.Tests/StateChangeInterceptorTests.cs
@@ -0,0 +1,815 @@
+#if EF_6
+using System.Data.Entity;
+#else
+using System.Data;
+#endif
+using System.Collections.Generic;
+using TrackableEntities.EF.Tests;
+using TrackableEntities.EF.Tests.Mocks;
+using TrackableEntities.EF.Tests.NorthwindModels;
+using Xunit;
+
+// ReSharper disable CheckNamespace
+#if EF_6
+namespace TrackableEntities.EF6.Tests
+#else
+namespace TrackableEntities.EF5.Tests
+#endif
+{
+    public class StateChangeInterceptorTests
+    {
+        // ReSharper disable once InconsistentNaming
+        private const CreateDbOptions CreateNorthwindDbOptions = CreateDbOptions.DropCreateDatabaseIfModelChanges;
+
+        #region No Relationship (Product)
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Change_Single_Entity_State(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var product = new Product();
+            product.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = setState ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<Product>((e, r) => state)
+                .ApplyChanges(product);
+
+            // Assert
+            var expectedState = setState ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(product).State);
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, true)]
+        [InlineData(false, false)]
+        public void State_Interceptor_Should_Mark_Multiple_Entities_States(bool setState1, bool setState2)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var products = new List<Product>
+            {
+                new Product { ProductId = 1, TrackingState = TrackingState.Added },
+                new Product { ProductId = 2, TrackingState = TrackingState.Deleted }
+            };
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Modified : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Product>((e, r) =>
+                {
+                    if (e.ProductId == 1)
+                        return states[0];
+                    if (e.ProductId == 2)
+                        return states[1];
+                    return null;
+                })
+                .ApplyChanges(products);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Modified : EntityState.Added,
+                setState2 ? EntityState.Unchanged : EntityState.Deleted,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(products[0]).State);
+            Assert.Equal(expectedStates[1], context.Entry(products[1]).State);
+        }
+
+        #endregion
+
+        #region 1-1 Relationship (Customer - CustomerSetting)
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_One_To_One_Entity_State(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var customer = nw.Customers[0];
+            var setting = customer.CustomerSetting = new CustomerSetting { CustomerId = customer.CustomerId, Setting = "Setting1", Customer = customer };
+            setting.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = setState ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<CustomerSetting>((e, r) => state)
+                .ApplyChanges(customer);
+
+            // Assert
+            var expectedState = setState ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(setting).State);
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, true)]
+        [InlineData(false, false)]
+        public void State_Interceptor_Should_Mark_One_To_One_MultiLevel_Entities_States(bool setState1, bool setState2)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var customer = nw.Customers[0];
+            var setting = customer.CustomerSetting = new CustomerSetting { CustomerId = customer.CustomerId, Setting = "Setting1", Customer = customer };
+            customer.TrackingState = TrackingState.Modified;
+            setting.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Customer>((e, r) => states[0])
+                .WithStateChangeInterceptor<CustomerSetting>((e, r) => states[1])
+                .ApplyChanges(customer);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(customer).State);
+            Assert.Equal(expectedStates[1], context.Entry(setting).State);
+        }
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_One_To_One_Entity_State_With_Added_Parent(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var customer = nw.Customers[0];
+            var setting = customer.CustomerSetting = new CustomerSetting { CustomerId = customer.CustomerId, Setting = "Setting1", Customer = customer };
+            customer.TrackingState = TrackingState.Added;
+
+            // Act
+            var state = setState ? EntityState.Modified : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<CustomerSetting>((e, r) => state)
+                .ApplyChanges(customer);
+
+            // Assert
+            var expectedState = setState ? EntityState.Modified : EntityState.Added;
+            Assert.Equal(expectedState, context.Entry(setting).State);
+        }
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_One_To_One_Entity_State_With_Deleted_Parent(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var customer = nw.Customers[0];
+            var setting = customer.CustomerSetting = new CustomerSetting { CustomerId = customer.CustomerId, Setting = "Setting1", Customer = customer };
+            customer.TrackingState = TrackingState.Deleted;
+
+            // Act
+            var state = setState ? EntityState.Modified : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<CustomerSetting>((e, r) => state)
+                .ApplyChanges(customer);
+
+            // Assert
+            var expectedState = setState ? EntityState.Modified : EntityState.Deleted;
+            Assert.Equal(expectedState, context.Entry(setting).State);
+        }
+
+        [Theory]
+        [InlineData(RelationshipType.OneToOne)]
+        [InlineData(null)]
+        public void State_Interceptor_Should_Mark_One_To_One_Entity_State_With_RelationType(RelationshipType? relationType)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var customer = nw.Customers[0];
+            var setting = customer.CustomerSetting = new CustomerSetting { CustomerId = customer.CustomerId, Setting = "Setting1", Customer = customer };
+            setting.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = relationType == RelationshipType.OneToOne ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<CustomerSetting>((e, r) => 
+                    r == RelationshipType.OneToOne ? state : null)
+                .ApplyChanges(customer);
+
+            // Assert
+            var expectedState = relationType == RelationshipType.OneToOne ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(setting).State);
+        }
+
+        #endregion
+
+        #region 1-M Relationship (Order - OrderDetail)
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_One_To_Many_Entity_State(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            detail1.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = setState ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<OrderDetail>((e, r) => state)
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedState = setState ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(detail1).State);
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, true)]
+        [InlineData(false, false)]
+        public void State_Interceptor_Should_Mark_One_To_Many_Entities_States(bool setState1, bool setState2)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            var detail2 = order.OrderDetails[1];
+            detail1.TrackingState = TrackingState.Modified;
+            detail2.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<OrderDetail>((e, r) =>
+                {
+                    if (e.OrderDetailId == 1)
+                        return states[0];
+                    if (e.OrderDetailId == 2)
+                        return states[1];
+                    return null;
+                })
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(detail1).State);
+            Assert.Equal(expectedStates[1], context.Entry(detail2).State);
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, true)]
+        [InlineData(false, false)]
+        public void State_Interceptor_Should_Mark_One_To_Many_MultiLevel_Entities_States(bool setState1, bool setState2)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            order.TrackingState = TrackingState.Modified;
+            detail1.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Order>((e, r) => states[0])
+                .WithStateChangeInterceptor<OrderDetail>((e, r) => states[1])
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(order).State);
+            Assert.Equal(expectedStates[1], context.Entry(detail1).State);
+        }
+
+        [Theory]
+        [InlineData(true, false, false)]
+        [InlineData(true, true, false)]
+        [InlineData(true, true, true)]
+        [InlineData(false, true, false)]
+        [InlineData(false, true, true)]
+        [InlineData(false, false, true)]
+        [InlineData(false, false, false)]
+        public void State_Interceptor_Should_Mark_One_To_Many_To_One_MultiLevel_Entities_States(
+            bool setState1, bool setState2, bool setState3)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            var product = order.OrderDetails[0].Product;
+            order.TrackingState = TrackingState.Modified;
+            detail1.TrackingState = TrackingState.Modified;
+            product.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+                setState3 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Order>((e, r) => states[0])
+                .WithStateChangeInterceptor<OrderDetail>((e, r) => states[1])
+                .WithStateChangeInterceptor<Product>((e, r) => states[2])
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+                setState3 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(order).State);
+            Assert.Equal(expectedStates[1], context.Entry(detail1).State);
+            Assert.Equal(expectedStates[2], context.Entry(product).State);
+        }
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_One_To_Many_Entity_State_With_Added_Parent(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            order.TrackingState = TrackingState.Added;
+
+            // Act
+            var state = setState ? EntityState.Modified : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<OrderDetail>((e, r) => state)
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedState = setState ? EntityState.Modified : EntityState.Added;
+            Assert.Equal(expectedState, context.Entry(detail1).State);
+        }
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_One_To_Many_Entity_State_With_Deleted_Parent(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            order.TrackingState = TrackingState.Deleted;
+
+            // Act
+            var state = setState ? EntityState.Modified : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<OrderDetail>((e, r) => state)
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedState = setState ? EntityState.Modified : EntityState.Deleted;
+            Assert.Equal(expectedState, context.Entry(detail1).State);
+        }
+
+        [Theory]
+        [InlineData(RelationshipType.OneToMany)]
+        [InlineData(null)]
+        public void State_Interceptor_Should_Mark_One_To_Many_Entity_State_With_RelationType(RelationshipType? relationType)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            detail1.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = relationType == RelationshipType.OneToMany ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<OrderDetail>((e, r) =>
+                    r == RelationshipType.OneToMany ? state : null)
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedState = relationType == RelationshipType.OneToMany ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(detail1).State);
+        }
+
+        #endregion
+
+        #region M-1 Relationship (Order - Customer)
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_Many_To_One_Entity_State(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var order = nw.Orders[0];
+            var customer = order.Customer;
+            customer.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = setState ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<Customer>((e, r) => state)
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedState = setState ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(customer).State);
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, true)]
+        [InlineData(false, false)]
+        public void State_Interceptor_Should_Mark_Many_To_One_MultiLevel_Entities_States(bool setState1, bool setState2)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var order = nw.Orders[0];
+            var customer = order.Customer;
+            order.TrackingState = TrackingState.Modified;
+            customer.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Order>((e, r) => states[0])
+                .WithStateChangeInterceptor<Customer>((e, r) => states[1])
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(order).State);
+            Assert.Equal(expectedStates[1], context.Entry(customer).State);
+        }
+
+        [Theory]
+        [InlineData(true, false, false)]
+        [InlineData(true, true, false)]
+        [InlineData(true, true, true)]
+        [InlineData(false, true, false)]
+        [InlineData(false, true, true)]
+        [InlineData(false, false, true)]
+        [InlineData(false, false, false)]
+        public void State_Interceptor_Should_Mark_Many_To_One_To_One_MultiLevel_Entities_States(
+            bool setState1, bool setState2, bool setState3)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var order = nw.Orders[0];
+            var customer = order.Customer;
+            var setting = customer.CustomerSetting = new CustomerSetting { CustomerId = customer.CustomerId, Setting = "Setting1", Customer = customer };
+            order.TrackingState = TrackingState.Modified;
+            customer.TrackingState = TrackingState.Modified;
+            setting.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+                setState3 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Order>((e, r) => states[0])
+                .WithStateChangeInterceptor<Customer>((e, r) => states[1])
+                .WithStateChangeInterceptor<CustomerSetting>((e, r) => states[2])
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+                setState3 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(order).State);
+            Assert.Equal(expectedStates[1], context.Entry(customer).State);
+            Assert.Equal(expectedStates[2], context.Entry(setting).State);
+        }
+
+        [Theory]
+        [InlineData(RelationshipType.ManyToOne)]
+        [InlineData(null)]
+        public void State_Interceptor_Should_Mark_Many_To_One_Entity_State_With_RelationType(RelationshipType? relationType)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var order = nw.Orders[0];
+            var customer = order.Customer;
+            customer.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = relationType == RelationshipType.ManyToOne ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<Customer>((e, r) =>
+                    r == RelationshipType.ManyToOne ? state : null)
+                .ApplyChanges(order);
+
+            // Assert
+            var expectedState = relationType == RelationshipType.ManyToOne ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(customer).State);
+        }
+
+        #endregion
+
+        #region M-M Relationship (Employees - Territories)
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_Many_To_Many_Entity_State(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var employee = nw.Employees[0];
+            var territory1 = employee.Territories[0];
+            employee.Territories = new List<Territory> { territory1 };
+            territory1.TrackingState = TrackingState.Modified;
+
+            // Act
+            var state = setState ? EntityState.Unchanged : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<Territory>((e, r) => state)
+                .ApplyChanges(employee);
+
+            // Assert
+            var expectedState = setState ? EntityState.Unchanged : EntityState.Modified;
+            Assert.Equal(expectedState, context.Entry(territory1).State);
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, true)]
+        [InlineData(false, false)]
+        public void State_Interceptor_Should_Mark_Many_To_Many_Entities_States(bool setState1, bool setState2)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var employee = nw.Employees[0];
+            var territory1 = employee.Territories[0];
+            var territory2 = employee.Territories[1];
+            employee.Territories = new List<Territory> { territory1, territory2 };
+            territory1.TrackingState = TrackingState.Modified;
+            territory2.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Territory>((e, r) =>
+                {
+                    if (e.TerritoryId == "01581")
+                        return states[0];
+                    if (e.TerritoryId == "01730")
+                        return states[1];
+                    return null;
+                })
+                .ApplyChanges(employee);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(territory1).State);
+            Assert.Equal(expectedStates[1], context.Entry(territory2).State);
+        }
+
+        [Theory]
+        [InlineData(true, true)]
+        [InlineData(true, false)]
+        [InlineData(false, true)]
+        [InlineData(false, false)]
+        public void State_Interceptor_Should_Mark_Many_To_Many_MultiLevel_Entities_States(bool setState1, bool setState2)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var employee = nw.Employees[0];
+            var territory1 = employee.Territories[0];
+            employee.Territories = new List<Territory> { territory1 };
+            employee.TrackingState = TrackingState.Modified;
+            territory1.TrackingState = TrackingState.Modified;
+
+            // Act
+            var states = new[]
+            {
+                setState1 ? EntityState.Unchanged : null as EntityState?,
+                setState2 ? EntityState.Unchanged : null as EntityState?,
+            };
+            context
+                .WithStateChangeInterceptor<Employee>((e, r) => states[0])
+                .WithStateChangeInterceptor<Territory>((e, r) => states[1])
+                .ApplyChanges(employee);
+
+            // Assert
+            var expectedStates = new[]
+            {
+                setState1 ? EntityState.Unchanged : EntityState.Modified,
+                setState2 ? EntityState.Unchanged : EntityState.Modified,
+            };
+            Assert.Equal(expectedStates[0], context.Entry(employee).State);
+            Assert.Equal(expectedStates[1], context.Entry(territory1).State);
+        }
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void State_Interceptor_Should_Mark_Many_To_Many_Entity_State_With_Added_Child(bool setState)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var employee = nw.Employees[0];
+            var territory1 = employee.Territories[0];
+            employee.Territories = new List<Territory> { territory1 };
+            employee.TrackingState = TrackingState.Unchanged;
+            territory1.TrackingState = TrackingState.Added;
+
+            // Act
+            var state = setState ? EntityState.Added : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<Territory>((e, r) => state)
+                .ApplyChanges(employee);
+
+            // Assert
+            var expectedState = setState ? EntityState.Added : EntityState.Unchanged;
+            Assert.Equal(expectedState, context.Entry(territory1).State);
+        }
+
+        [Theory]
+        [InlineData(RelationshipType.ManyToMany)]
+        [InlineData(null)]
+        public void State_Interceptor_Should_Mark_Many_To_Many_Entity_State_With_RelationType(RelationshipType? relationType)
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            var employee = nw.Employees[0];
+            var territory1 = employee.Territories[0];
+            employee.Territories = new List<Territory> { territory1 };
+            employee.TrackingState = TrackingState.Unchanged;
+            territory1.TrackingState = TrackingState.Added;
+
+            // Act
+            var state = relationType == RelationshipType.ManyToMany ? EntityState.Added : null as EntityState?;
+            context
+                .WithStateChangeInterceptor<Territory>((e, r) =>
+                    r == RelationshipType.ManyToMany ? state : null)
+                .ApplyChanges(employee);
+
+            // Assert
+            var expectedState = relationType == RelationshipType.ManyToMany ? EntityState.Added : EntityState.Unchanged;
+            Assert.Equal(expectedState, context.Entry(territory1).State);
+        }
+
+        #endregion
+
+        #region Multiple State Interceptors
+
+        [Fact]
+        public void Last_Interceptor_Should_Win()
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var order = new MockNorthwind().Orders[0];
+            var detail1 = order.OrderDetails[0];
+            var detail2 = order.OrderDetails[1];
+            var detail3 = order.OrderDetails[2];
+
+            order.TrackingState = TrackingState.Unchanged;
+            detail1.TrackingState = TrackingState.Unchanged;
+            detail2.TrackingState = TrackingState.Unchanged;
+            detail3.TrackingState = TrackingState.Unchanged;
+
+            var orderId = order.OrderId;
+            var detailId1 = detail1.OrderDetailId;
+            var detailId2 = detail2.OrderDetailId;
+            var detailId3 = detail3.OrderDetailId;
+
+            // Act
+            context
+                // Order -> Deleted
+                .WithStateChangeInterceptor<Order>((e, rs) =>
+                {
+                    if (e.OrderId == orderId)
+                        return EntityState.Deleted;
+
+                    return null;
+                })
+                // OrderDetail 1 -> Added   <====== FINAL STATE
+                // OrderDetail 2 -> Modidfied
+                // OrderDetail 3 -> Deleted
+                .WithStateChangeInterceptor<OrderDetail>((e, rs) =>
+                {
+                    if (e.OrderDetailId == detailId1)
+                        return EntityState.Added;
+
+                    if (e.OrderDetailId == detailId2)
+                        return EntityState.Modified;
+
+                    if (e.OrderDetailId == detailId3)
+                        return EntityState.Deleted;
+
+                    return null;
+                })
+                // Order -> Modified   <====== FINAL STATE
+                .WithStateChangeInterceptor<Order>((e, rs) =>
+                {
+                    if (e.OrderId == orderId)
+                        return EntityState.Modified;
+
+                    return null;
+                })
+                // OrderDetail 2 -> Added   <====== FINAL STATE
+                .WithStateChangeInterceptor<OrderDetail>((e, rs) =>
+                {
+                    if (e.OrderDetailId == detailId2)
+                        return EntityState.Added;
+
+                    return null;
+                })
+                // OrderDetail 3 -> Modified   <====== FINAL STATE
+                .WithStateChangeInterceptor<OrderDetail>((e, rs) =>
+                {
+                    if (e.OrderDetailId == detailId3)
+                        return EntityState.Modified;
+
+                    return null;
+                })
+                .ApplyChanges(order);
+
+            // Assert
+            Assert.Equal(EntityState.Modified, context.Entry(order).State);
+            Assert.Equal(EntityState.Added, context.Entry(detail1).State);
+            Assert.Equal(EntityState.Added, context.Entry(detail2).State);
+            Assert.Equal(EntityState.Modified, context.Entry(detail3).State);
+        }
+
+        #endregion
+    }
+}
diff --git a/Source/Tests/TrackableEntities.EF.5.Tests/StateInterceptorTests.cs b/Source/Tests/TrackableEntities.EF.5.Tests/StateInterceptorTests.cs
new file mode 100644
index 00000000..e91a2004
--- /dev/null
+++ b/Source/Tests/TrackableEntities.EF.5.Tests/StateInterceptorTests.cs
@@ -0,0 +1,105 @@
+#if EF_6
+using System.Data.Entity;
+#else
+using System.Data;
+#endif
+using System.Collections.Generic;
+using System.Linq;
+using TrackableEntities.EF.Tests;
+using TrackableEntities.EF.Tests.Mocks;
+using TrackableEntities.EF.Tests.NorthwindModels;
+using Xunit;
+
+// ReSharper disable CheckNamespace
+#if EF_6
+namespace TrackableEntities.EF6.Tests
+#else
+namespace TrackableEntities.EF5.Tests
+#endif
+{
+    public class StateInterceptorTests
+    {
+        // ReSharper disable once InconsistentNaming
+        private const CreateDbOptions CreateNorthwindDbOptions = CreateDbOptions.DropCreateDatabaseIfModelChanges;
+
+        [Fact]
+        public void Interceptor_Should_Change_Entities_States()
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            int[] ids = {1, 2, 3};
+            var products = nw.Products.Where(e => ids.Contains(e.ProductId)).ToList();
+            products.ForEach(e => e.TrackingState = TrackingState.Modified);
+            var cache = new Dictionary<int, EntityState>
+            {
+                { 1, EntityState.Added },
+                { 2, EntityState.Deleted },
+                { 3, EntityState.Unchanged },
+            };
+
+            // Act
+            context
+                .WithInterceptor(new ProductCacheStateInterceptor(cache))
+                .ApplyChanges(products);
+
+            // Assert
+            Assert.Equal(EntityState.Added, context.Entry(products[0]).State);
+            Assert.Equal(EntityState.Deleted, context.Entry(products[1]).State);
+            Assert.Equal(EntityState.Unchanged, context.Entry(products[2]).State);
+        }
+
+        [Fact]
+        public void Interceptor_Should_Not_Change_Entities_States()
+        {
+            // Arrange
+            var context = TestsHelper.CreateNorthwindDbContext(CreateNorthwindDbOptions);
+            var nw = new MockNorthwind();
+            int[] ids = { 4, 5, 6 };
+            var products = nw.Products.Where(e => ids.Contains(e.ProductId)).ToList();
+            products.ForEach(e => e.TrackingState = TrackingState.Modified);
+            var cache = new Dictionary<int, EntityState>
+            {
+                { 1, EntityState.Added },
+                { 2, EntityState.Deleted },
+                { 3, EntityState.Unchanged },
+            };
+
+            // Act
+            context
+                .WithInterceptor(new ProductCacheStateInterceptor(cache))
+                .ApplyChanges(products);
+
+            // Assert
+            Assert.Equal(EntityState.Modified, context.Entry(products[0]).State);
+            Assert.Equal(EntityState.Modified, context.Entry(products[1]).State);
+            Assert.Equal(EntityState.Modified, context.Entry(products[2]).State);
+        }
+
+        #region IStateInterceptor Implementations
+
+        // Look up entity states in a products cache
+        private class ProductCacheStateInterceptor : IStateInterceptor
+        {
+            private readonly Dictionary<int, EntityState> _cache;
+
+            public ProductCacheStateInterceptor(Dictionary<int, EntityState> cache)
+            {
+                _cache = cache;
+            }
+             
+            public EntityState? GetEntityState(ITrackable item, RelationshipType? relationshipType)
+            {
+                var product = item as Product;
+                if (product == null) return null;
+
+                EntityState state;
+                if (_cache.TryGetValue(product.ProductId, out state))
+                    return state;
+                return null;
+            }
+        }
+
+        #endregion
+    }
+}
diff --git a/Source/Tests/TrackableEntities.EF.5.Tests/TrackableEntities.EF.5.Tests.csproj b/Source/Tests/TrackableEntities.EF.5.Tests/TrackableEntities.EF.5.Tests.csproj
index 18b39ffd..ebcdc717 100644
--- a/Source/Tests/TrackableEntities.EF.5.Tests/TrackableEntities.EF.5.Tests.csproj
+++ b/Source/Tests/TrackableEntities.EF.5.Tests/TrackableEntities.EF.5.Tests.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props" Condition="Exists('..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props')" />
+  <Import Project="..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -15,6 +14,8 @@
     <FileAlignment>512</FileAlignment>
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -52,12 +53,16 @@
       <HintPath>..\..\packages\xunit.abstractions.2.0.0\lib\net35\xunit.abstractions.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="xunit.assert, Version=2.0.0.2929, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\xunit.assert.2.0.0\lib\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.assert.dll</HintPath>
+    <Reference Include="xunit.assert, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.assert.2.1.0\lib\dotnet\xunit.assert.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="xunit.core, Version=2.0.0.2929, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\xunit.extensibility.core.2.0.0\lib\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.dll</HintPath>
+    <Reference Include="xunit.core, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.extensibility.core.2.1.0\lib\dotnet\xunit.core.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="xunit.execution.desktop, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.extensibility.execution.2.1.0\lib\net45\xunit.execution.desktop.dll</HintPath>
       <Private>True</Private>
     </Reference>
   </ItemGroup>
@@ -65,6 +70,8 @@
     <Compile Include="..\..\TrackableEntities.EF.5\Constants.cs">
       <Link>Constants.cs</Link>
     </Compile>
+    <Compile Include="StateInterceptorTests.cs" />
+    <Compile Include="StateChangeInterceptorTests.cs" />
     <Compile Include="Contexts\NorthwindDbContext.cs" />
     <Compile Include="LoadRelatedEntitiesTests.cs" />
     <Compile Include="NorthwindDbContextTests.cs" />
@@ -125,10 +132,9 @@
   <Import Project="$(SolutionDir)\.nuget\nuget.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props'))" />
-    <Error Condition="!Exists('..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props'))" />
+    <Error Condition="!Exists('..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
   </Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
diff --git a/Source/Tests/TrackableEntities.EF.5.Tests/packages.config b/Source/Tests/TrackableEntities.EF.5.Tests/packages.config
index 452894fd..ecf59976 100644
--- a/Source/Tests/TrackableEntities.EF.5.Tests/packages.config
+++ b/Source/Tests/TrackableEntities.EF.5.Tests/packages.config
@@ -1,10 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="EntityFramework" version="5.0.0" targetFramework="net45" />
-  <package id="xunit" version="2.0.0" targetFramework="net45" />
+  <package id="xunit" version="2.1.0" targetFramework="net45" />
   <package id="xunit.abstractions" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.assert" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.core" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.extensibility.core" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.runner.visualstudio" version="2.0.0" targetFramework="net45" />
+  <package id="xunit.assert" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.execution" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.runner.visualstudio" version="2.1.0" targetFramework="net45" />
 </packages>
\ No newline at end of file
diff --git a/Source/Tests/TrackableEntities.EF.6.Tests/TrackableEntities.EF.6.Tests.csproj b/Source/Tests/TrackableEntities.EF.6.Tests/TrackableEntities.EF.6.Tests.csproj
index b9f6abe2..84124d9e 100644
--- a/Source/Tests/TrackableEntities.EF.6.Tests/TrackableEntities.EF.6.Tests.csproj
+++ b/Source/Tests/TrackableEntities.EF.6.Tests/TrackableEntities.EF.6.Tests.csproj
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props" Condition="Exists('..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props')" />
+  <Import Project="..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -16,6 +15,8 @@
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
     <TargetFrameworkProfile />
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -55,12 +56,16 @@
       <HintPath>..\..\packages\xunit.abstractions.2.0.0\lib\net35\xunit.abstractions.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="xunit.assert, Version=2.0.0.2929, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\xunit.assert.2.0.0\lib\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.assert.dll</HintPath>
+    <Reference Include="xunit.assert, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.assert.2.1.0\lib\dotnet\xunit.assert.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="xunit.core, Version=2.0.0.2929, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\xunit.extensibility.core.2.0.0\lib\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.dll</HintPath>
+    <Reference Include="xunit.core, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.extensibility.core.2.1.0\lib\dotnet\xunit.core.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="xunit.execution.desktop, Version=2.1.0.3179, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\xunit.extensibility.execution.2.1.0\lib\net45\xunit.execution.desktop.dll</HintPath>
       <Private>True</Private>
     </Reference>
   </ItemGroup>
@@ -152,6 +157,12 @@
     <Compile Include="..\TrackableEntities.EF.5.Tests\NorthwindModels\Territory.cs">
       <Link>NorthwindModels\Territory.cs</Link>
     </Compile>
+    <Compile Include="..\TrackableEntities.EF.5.Tests\StateChangeInterceptorTests.cs">
+      <Link>StateChangeInterceptorTests.cs</Link>
+    </Compile>
+    <Compile Include="..\TrackableEntities.EF.5.Tests\StateInterceptorTests.cs">
+      <Link>StateInterceptorTests.cs</Link>
+    </Compile>
     <Compile Include="..\TrackableEntities.EF.5.Tests\TrackableExtensionsTests.cs">
       <Link>TrackableExtensionsTests.cs</Link>
     </Compile>
@@ -165,7 +176,9 @@
       <Link>Edmx\NorthwindModel.edmx</Link>
     </EntityDeploy>
     <None Include="App.config" />
-    <None Include="packages.config" />
+    <None Include="packages.config">
+      <SubType>Designer</SubType>
+    </None>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\TrackableEntities.Common\TrackableEntities.Common.csproj">
@@ -184,10 +197,9 @@
   <Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props'))" />
-    <Error Condition="!Exists('..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\xunit.runner.visualstudio.2.0.0\build\net20\xunit.runner.visualstudio.props'))" />
+    <Error Condition="!Exists('..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
   </Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
diff --git a/Source/Tests/TrackableEntities.EF.6.Tests/packages.config b/Source/Tests/TrackableEntities.EF.6.Tests/packages.config
index 36463f32..d11638b9 100644
--- a/Source/Tests/TrackableEntities.EF.6.Tests/packages.config
+++ b/Source/Tests/TrackableEntities.EF.6.Tests/packages.config
@@ -1,10 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="EntityFramework" version="6.1.3" targetFramework="net45" />
-  <package id="xunit" version="2.0.0" targetFramework="net45" />
+  <package id="xunit" version="2.1.0" targetFramework="net45" />
   <package id="xunit.abstractions" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.assert" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.core" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.extensibility.core" version="2.0.0" targetFramework="net45" />
-  <package id="xunit.runner.visualstudio" version="2.0.0" targetFramework="net45" />
+  <package id="xunit.assert" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.core" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.extensibility.execution" version="2.1.0" targetFramework="net45" />
+  <package id="xunit.runner.visualstudio" version="2.1.0" targetFramework="net45" />
 </packages>
\ No newline at end of file
diff --git a/Source/TrackableEntities.EF.5/Constants.cs b/Source/TrackableEntities.EF.5/Constants.cs
index a0f64111..5ac061d9 100644
--- a/Source/TrackableEntities.EF.5/Constants.cs
+++ b/Source/TrackableEntities.EF.5/Constants.cs
@@ -13,6 +13,9 @@ public static class ExceptionMessages
             public const string DeletedWithAddedChildren =
                 "An entity may not be marked as Deleted if it has related entities which are marked as Added. " +
                 "Remove added related entities before deleting a parent entity.";
+
+            public const string RelationshipNotDetermined =
+                "Cannot determine relationship type for {0} property on {1}.";
         }
     }
 }
diff --git a/Source/TrackableEntities.EF.5/DbContextExtensions.cs b/Source/TrackableEntities.EF.5/DbContextExtensions.cs
index 9fdefb76..7901d054 100644
--- a/Source/TrackableEntities.EF.5/DbContextExtensions.cs
+++ b/Source/TrackableEntities.EF.5/DbContextExtensions.cs
@@ -11,10 +11,12 @@
 using System.Threading.Tasks;
 using System.Data.Entity.Core.Objects;
 using System.Data.Entity.Core.Metadata.Edm;
+using TrackableEntities.EF6.Exceptions;
 #else
 using System.Data;
 using System.Data.Objects;
 using System.Data.Metadata.Edm;
+using TrackableEntities.EF5.Exceptions;
 #endif
 
 #if EF_6
@@ -36,7 +38,7 @@ public static class DbContextExtensions
         public static void ApplyChanges(this DbContext context, ITrackable item)
         {
             // Recursively set entity state for DbContext entry
-            ApplyChanges(context, item, null, new ObjectVisitationHelper(), null);
+            ApplyChanges(context, item, null, new ObjectVisitationHelper(), null, null, null);
         }
 
         /// <summary>
@@ -48,12 +50,36 @@ public static void ApplyChanges(this DbContext context, IEnumerable<ITrackable>
         {
             // Apply changes to collection of items
             foreach (var item in items)
-                ApplyChanges(context, item, null, new ObjectVisitationHelper(), null);
+                ApplyChanges(context, item, null, new ObjectVisitationHelper(), null, null, null);
+        }
+
+        /// <summary>
+        /// Update entity state on DbContext for an object graph with interception.
+        /// </summary>
+        /// <param name="pool">Pool of interceptors</param>
+        /// <param name="item">Object that implements ITrackable</param>
+        public static void ApplyChanges(this InterceptorPool pool, ITrackable item)
+        {
+            // Recursively set entity state for DbContext entry
+            ApplyChanges(pool.DbContext, item, null, new ObjectVisitationHelper(), null, null, pool.Interceptors);
+        }
+
+        /// <summary>
+        /// Update entity state on DbContext for more than one object graph.
+        /// </summary>
+        /// <param name="pool">Pool of interceptors</param>
+        /// <param name="items">Objects that implement ITrackable</param>
+        public static void ApplyChanges(this InterceptorPool pool, IEnumerable<ITrackable> items)
+        {
+            // Apply changes to collection of items
+            foreach (var item in items)
+                ApplyChanges(pool.DbContext, item, null, new ObjectVisitationHelper(), null, null, pool.Interceptors);
         }
 
         private static void ApplyChanges(this DbContext context,
             ITrackable item, ITrackable parent, ObjectVisitationHelper visitationHelper,
-            string propertyName, TrackingState? state = null)
+            string propertyName, TrackingState? state,
+            IList<IStateInterceptor> interceptors)
         {
             // Prevent endless recursion
             if (!visitationHelper.TryVisit(item)) return;
@@ -66,8 +92,8 @@ private static void ApplyChanges(this DbContext context,
 
             // If M-M child, set relationship for added or deleted items
             if (parent != null && propertyName != null
-                && (context.IsRelatedProperty(parent.GetType(), 
-                propertyName, RelationshipType.ManyToMany)))
+                && (context.IsRelatedProperty(parent.GetType(),
+                    propertyName, RelationshipType.ManyToMany)))
             {
                 // If parent is added set tracking state to match
                 var trackingState = item.TrackingState;
@@ -79,9 +105,10 @@ private static void ApplyChanges(this DbContext context,
                 if (trackingState == TrackingState.Added
                     || trackingState == TrackingState.Deleted)
                 {
-                    context.Entry(item).State = item.TrackingState == TrackingState.Modified
+                    var entityState = item.TrackingState == TrackingState.Modified
                         ? EntityState.Modified
-                        : EntityState.Unchanged;                    
+                        : EntityState.Unchanged;
+                    SetEntityState(context, item, parent, propertyName, entityState, interceptors);
                     context.SetRelationshipState(item, parent, propertyName,
                         trackingState.ToEntityState());
                 }
@@ -89,13 +116,13 @@ private static void ApplyChanges(this DbContext context,
                 {
                     // Set entity state for modified or unchanged
                     if (item.TrackingState == TrackingState.Modified)
-                        context.Entry(item).State = EntityState.Modified;
+                        SetEntityState(context, item, parent, propertyName, EntityState.Modified, interceptors);
                     else if (item.TrackingState == TrackingState.Unchanged)
-                        context.Entry(item).State = EntityState.Unchanged;
+                        SetEntityState(context, item, parent, propertyName, EntityState.Unchanged, interceptors);
                 }
 
                 // Set state for child collections
-                context.ApplyChangesOnProperties(item, visitationHelper);
+                context.ApplyChangesOnProperties(item, visitationHelper, null, interceptors);
                 return;
             }
 
@@ -104,8 +131,10 @@ private static void ApplyChanges(this DbContext context,
                 && item.TrackingState != TrackingState.Deleted
                 && parent.TrackingState == TrackingState.Deleted
                 && !context.IsRelatedProperty(parent.GetType(),
-                    propertyName, RelationshipType.ManyToOne))
+                propertyName, RelationshipType.ManyToOne))
+            {
                 return;
+            }
 
             // If it is a M-1 relation and item state is deleted,
             // set to unchanged and exit
@@ -116,7 +145,7 @@ private static void ApplyChanges(this DbContext context,
             {
                 try
                 {
-                    context.Entry(item).State = EntityState.Unchanged;
+                    SetEntityState(context, item, parent, propertyName, EntityState.Unchanged, interceptors);
                 }
                 catch (InvalidOperationException invalidOpEx)
                 {
@@ -129,8 +158,8 @@ private static void ApplyChanges(this DbContext context,
             if (item.TrackingState == TrackingState.Added
                 && (state == null || state == TrackingState.Added))
             {
-                context.Entry(item).State = EntityState.Added;
-                context.ApplyChangesOnProperties(item, visitationHelper);
+                SetEntityState(context, item, parent, propertyName, EntityState.Added, interceptors);
+                context.ApplyChangesOnProperties(item, visitationHelper, null, interceptors);
                 return;
             }
 
@@ -140,7 +169,8 @@ private static void ApplyChanges(this DbContext context,
                 && (context.IsRelatedProperty(parent.GetType(), propertyName, RelationshipType.OneToMany)
                     || context.IsRelatedProperty(parent.GetType(), propertyName, RelationshipType.OneToOne)))
             {
-                context.ApplyChangesOnProperties(item, visitationHelper);
+                context.ApplyChangesOnProperties(item, visitationHelper, null, interceptors);
+                TrySetEntityState(context, item, parent, propertyName, interceptors);
                 return;
             }
 
@@ -148,8 +178,8 @@ private static void ApplyChanges(this DbContext context,
             if (item.TrackingState == TrackingState.Deleted
                 && (state == null || state == TrackingState.Deleted))
             {
-                context.SetChanges(item, EntityState.Unchanged, visitationHelper.Clone()); // Clone to avoid interference
-                context.SetChanges(item, EntityState.Deleted, visitationHelper);
+                context.SetChanges(item, EntityState.Unchanged, visitationHelper.Clone(), null, null, interceptors); // Clone to avoid interference
+                context.SetChanges(item, EntityState.Deleted, visitationHelper, null, null, interceptors);
                 return;
             }
 
@@ -161,12 +191,12 @@ private static void ApplyChanges(this DbContext context,
                     && item.TrackingState != TrackingState.Deleted))
             {
                 // Set added state for reference or child properties
-                context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Added); // Clone to avoid interference
+                context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Added, interceptors); // Clone to avoid interference
 
                 // Delete children prior to parent
                 if (item.TrackingState == TrackingState.Deleted)
                 {
-                    context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Deleted);
+                    context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Deleted, interceptors);
                 }
 
                 // Set modified properties
@@ -176,26 +206,26 @@ private static void ApplyChanges(this DbContext context,
                     && item.ModifiedProperties.Count > 0)
                 {
                     // Mark modified properties
-                    context.Entry(item).State = EntityState.Unchanged;
+                    SetEntityState(context, item, parent, propertyName, EntityState.Unchanged, interceptors);
                     foreach (var property in item.ModifiedProperties)
                         context.Entry(item).Property(property).IsModified = true;
                 }
                 else
                 {
                     // Set entity state
-                    context.Entry(item).State = item.TrackingState.ToEntityState();
+                    SetEntityState(context, item, parent, propertyName, item.TrackingState.ToEntityState(), interceptors);
                 }
 
                 // Set other state for reference or child properties
-                context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Unchanged); // Clone to avoid interference
+                context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Unchanged, interceptors); // Clone to avoid interference
                 if (item.TrackingState == TrackingState.Deleted)
                 {
-                    context.ApplyChangesOnProperties(item, visitationHelper, TrackingState.Modified); // Clone to avoid interference
+                    context.ApplyChangesOnProperties(item, visitationHelper, TrackingState.Modified, interceptors); // Clone to avoid interference
                 }
                 else
                 {
-                    context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Modified); // Clone to avoid interference
-                    context.ApplyChangesOnProperties(item, visitationHelper, TrackingState.Deleted); 
+                    context.ApplyChangesOnProperties(item, visitationHelper.Clone(), TrackingState.Modified, interceptors); // Clone to avoid interference
+                    context.ApplyChangesOnProperties(item, visitationHelper, TrackingState.Deleted, interceptors); 
                 }
             }
         }
@@ -469,14 +499,15 @@ private static EntityType GetEdmSpaceType(this DbContext dbContext, Type entityT
         #region ApplyChanges Helpers
 
         private static void ApplyChangesOnProperties(this DbContext context,
-            ITrackable item, ObjectVisitationHelper visitationHelper, TrackingState? state = null)
+            ITrackable item, ObjectVisitationHelper visitationHelper,
+            TrackingState? state, IList<IStateInterceptor> interceptors)
         {
             // Recursively apply changes
             foreach (var navProp in item.GetNavigationProperties())
             {
                 // Apply changes to 1-1 and M-1 properties
                 foreach (var refProp in navProp.AsReferenceProperty())
-                    context.ApplyChanges(refProp.EntityReference, item, visitationHelper, navProp.Property.Name, state);
+                    context.ApplyChanges(refProp.EntityReference, item, visitationHelper, navProp.Property.Name, state, interceptors);
 
                 // Apply changes to 1-M and M-M properties
                 foreach (var colProp in navProp.AsCollectionProperty<IList>())
@@ -484,16 +515,17 @@ private static void ApplyChangesOnProperties(this DbContext context,
                     // Apply changes on collection property for each state.
                     // Process added items first, then process others.
                     ApplyChangesOnCollectionProperties(TrackingState.Added, true,
-                        navProp, colProp, context, item, visitationHelper, state);
+                        navProp, colProp, context, item, visitationHelper, state, interceptors);
                     ApplyChangesOnCollectionProperties(TrackingState.Added, false,
-                        navProp, colProp, context, item, visitationHelper, state);
+                        navProp, colProp, context, item, visitationHelper, state, interceptors);
                 }
             }
         }
 
         private static void ApplyChangesOnCollectionProperties(TrackingState stateFilter, bool includeState,
             EntityNavigationProperty navProp, EntityCollectionProperty<IList> colProp,
-            DbContext context, ITrackable item, ObjectVisitationHelper visitationHelper, TrackingState? state = null)
+            DbContext context, ITrackable item, ObjectVisitationHelper visitationHelper,
+            TrackingState? state, IList<IStateInterceptor> interceptors)
         {
             // Apply changes to 1-M and M-M properties filtering by tracking state
             var count = colProp.EntityCollection.Count;
@@ -506,7 +538,7 @@ private static void ApplyChangesOnCollectionProperties(TrackingState stateFilter
                         ? trackableChild.TrackingState == stateFilter
                         : trackableChild.TrackingState != stateFilter;
                     if (condition)
-                        context.ApplyChanges(trackableChild, item, visitationHelper, navProp.Property.Name, state);                    
+                        context.ApplyChanges(trackableChild, item, visitationHelper, navProp.Property.Name, state, interceptors);                    
                 } 
             }
         }
@@ -514,7 +546,8 @@ private static void ApplyChangesOnCollectionProperties(TrackingState stateFilter
         private static void SetChanges(this DbContext context,
             ITrackable item, EntityState state,
             ObjectVisitationHelper visitationHelper,
-            ITrackable parent = null, string propertyName = null)
+            ITrackable parent, string propertyName,
+            IList<IStateInterceptor> interceptors)
         {
             // Set state for child collections
             foreach (var navProp in item.GetNavigationProperties())
@@ -527,9 +560,9 @@ private static void SetChanges(this DbContext context,
                     ITrackable trackableReference = refProp.EntityReference;
                     if (visitationHelper.IsVisited(trackableReference)) continue;
 
-                    context.ApplyChanges(trackableReference, item, visitationHelper, propName);
+                    context.ApplyChanges(trackableReference, item, visitationHelper, propName, null, interceptors);
                     if (context.IsRelatedProperty(item.GetType(), propName, RelationshipType.OneToOne))
-                        context.SetChanges(trackableReference, state, visitationHelper, item, propName);
+                        context.SetChanges(trackableReference, state, visitationHelper, item, propName, interceptors);
                 }
 
                 // Apply changes to 1-M and M-M properties
@@ -542,7 +575,7 @@ private static void SetChanges(this DbContext context,
                         {
                             // TRICKY: we have just visited the item
                             // As a side effect, ApplyChanges will never be called for it.
-                            context.SetChanges(trackableChild, state, visitationHelper, item, propName);
+                            context.SetChanges(trackableChild, state, visitationHelper, item, propName, interceptors);
                         }
                     }
                 }
@@ -553,17 +586,19 @@ private static void SetChanges(this DbContext context,
                 && (context.IsRelatedProperty(parent.GetType(),
                 propertyName, RelationshipType.ManyToMany)))
             {
-                context.Entry(item).State = item.TrackingState == TrackingState.Modified
+                var entityState = item.TrackingState == TrackingState.Modified
                     ? EntityState.Modified
                     : EntityState.Unchanged;
+                SetEntityState(context, item, parent, propertyName, entityState, interceptors);
                 context.SetRelationshipState(item, parent, propertyName, EntityState.Deleted);
                 return;
             }
 
             // Set entity state
-            context.Entry(item).State = state;
+            SetEntityState(context, item, parent, propertyName, state, interceptors);
         }
 
+        // TODO: refactor to use GetRelationshipType() method
         private static bool IsRelatedProperty(this DbContext dbContext,
             Type entityType, string propertyName, RelationshipType relationshipType)
         {
@@ -624,12 +659,82 @@ private static EntityState ToEntityState(this TrackingState state)
             }
         }
 
-        enum RelationshipType
+        private static RelationshipType GetRelationshipType(this DbContext dbContext, Type entityType, string propertyName)
         {
-            ManyToOne,
-            OneToOne,
-            ManyToMany,
-            OneToMany
+            // Get navigation property
+            var edmEntityType = dbContext.GetEdmSpaceType(entityType);
+            if (edmEntityType == null)
+                throw new ArgumentException("Getting entity type from metadata failed.", "entityType");
+            var navProp = edmEntityType.NavigationProperties
+                .SingleOrDefault(p => p.Name == propertyName);
+            if (navProp == null)
+                throw new ArgumentException("Getting navigation property failed.", "propertyName");
+
+            if (navProp.FromEndMember.RelationshipMultiplicity == RelationshipMultiplicity.One
+                && (navProp.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.ZeroOrOne
+                    || navProp.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.One))
+                return RelationshipType.OneToOne;
+
+            if (navProp.FromEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many
+                && (navProp.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.ZeroOrOne
+                    || navProp.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.One))
+                return RelationshipType.ManyToOne;
+
+            if (navProp.FromEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many
+                && navProp.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many)
+                return RelationshipType.ManyToMany;
+
+            if ((navProp.FromEndMember.RelationshipMultiplicity == RelationshipMultiplicity.One
+                 || navProp.FromEndMember.RelationshipMultiplicity == RelationshipMultiplicity.ZeroOrOne)
+                && navProp.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many)
+                return RelationshipType.OneToMany;
+
+            throw new RelationshipNotDeterminedException(string.Format(Constants.ExceptionMessages.RelationshipNotDetermined, propertyName, entityType.FullName));
+        }
+
+        private static bool TrySetEntityState(DbContext context,
+            ITrackable item, ITrackable parent, string propertyName,
+            IList<IStateInterceptor> interceptors)
+        {
+            // If there are no state interceptors, do not use them
+            if (interceptors == null || interceptors.Count <= 0)
+                return false;
+
+            var interceptionStateUsed = false;
+            RelationshipType? relationType = null;
+
+            if (parent != null && propertyName != null)
+                relationType = GetRelationshipType(context, parent.GetType(), propertyName);
+
+            foreach (IStateInterceptor interceptor in interceptors)
+            {
+                // If current interceptor returns the state, use it
+                var entityState = interceptor.GetEntityState(item, relationType);
+                if (entityState != null)
+                {
+                    context.Entry(item).State = (EntityState)entityState;
+                    interceptionStateUsed = true;
+                }
+            }
+
+            return interceptionStateUsed;
+        }
+
+        private static void SetEntityState(DbContext context,
+            ITrackable item, ITrackable parent, string propertyName,
+            EntityState state, IList<IStateInterceptor> interceptors)
+        {
+            // Set state normally if we cannot perform interception
+            if (interceptors == null || interceptors.Count == 0)
+            {
+                context.Entry(item).State = state;
+                return;
+            }
+
+            // Try to use interceptors to set the state
+            // If no interceptor has changed the state, set state normally
+            if (!TrySetEntityState(context, item, parent, propertyName, interceptors))
+                context.Entry(item).State = state;
         }
 
         #endregion
diff --git a/Source/TrackableEntities.EF.5/Exceptions/RelationshipNotDeterminedException.cs b/Source/TrackableEntities.EF.5/Exceptions/RelationshipNotDeterminedException.cs
new file mode 100644
index 00000000..69b214ea
--- /dev/null
+++ b/Source/TrackableEntities.EF.5/Exceptions/RelationshipNotDeterminedException.cs
@@ -0,0 +1,21 @@
+#if EF_6
+namespace TrackableEntities.EF6.Exceptions
+#else
+namespace TrackableEntities.EF5.Exceptions
+#endif
+{
+    /// <summary>
+    /// Exception for state when the relationship cannot be determined for a given type and a givven property.
+    /// </summary>
+    public class RelationshipNotDeterminedException : TrackableEntitiesException
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="T:RelationshipNotDeterminedException"/> class with a specified error message.
+        /// </summary>
+        /// <param name="message">A message that describes the error </param>
+        public RelationshipNotDeterminedException(string message)
+            : base(message)
+        {
+        }        
+    }
+}
\ No newline at end of file
diff --git a/Source/TrackableEntities.EF.5/Exceptions/TrackableEntitiesException.cs b/Source/TrackableEntities.EF.5/Exceptions/TrackableEntitiesException.cs
new file mode 100644
index 00000000..26335f02
--- /dev/null
+++ b/Source/TrackableEntities.EF.5/Exceptions/TrackableEntitiesException.cs
@@ -0,0 +1,40 @@
+using System;
+
+#if EF_6
+namespace TrackableEntities.EF6.Exceptions
+#else
+namespace TrackableEntities.EF5.Exceptions
+#endif
+{
+    /// <summary>
+    /// Base class for exceptions defined in Trackable Entities.
+    /// </summary>
+    public abstract class TrackableEntitiesException : Exception
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="T:TrackableEntitiesException"/> class.
+        /// </summary>
+        protected TrackableEntitiesException()
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="T:TrackableEntitiesException"/> class with a specified error message.
+        /// </summary>
+        /// <param name="message">A message that describes the error.</param>
+        protected TrackableEntitiesException(string message)
+            : base(message)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="T:TrackableEntitiesException"/> class with a specified error message and a reference to the inner exception that is the cause of this exception.
+        /// </summary>
+        /// <param name="message">The error message that explains the reason for the exception.</param>
+        /// <param name="innerException">The exception that is the cause of the current exception. If the <paramref name="innerException"/> parameter is not a null reference, the current exception is raised in a catch block that handles the inner exception.</param>
+        protected TrackableEntitiesException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+    }
+}
diff --git a/Source/TrackableEntities.EF.5/IStateInterceptor.cs b/Source/TrackableEntities.EF.5/IStateInterceptor.cs
new file mode 100644
index 00000000..46596d1d
--- /dev/null
+++ b/Source/TrackableEntities.EF.5/IStateInterceptor.cs
@@ -0,0 +1,26 @@
+using System.Data.Entity;
+#if EF_6
+#else
+using System.Data;
+#endif
+
+#if EF_6
+namespace TrackableEntities.EF6
+#else
+namespace TrackableEntities.EF5
+#endif
+{
+    /// <summary>
+    /// Interface implemented by interceptors added to <see cref="DbContextExtensions.ApplyChanges(DbContext,ITrackable)"/>.
+    /// </summary>
+    public interface IStateInterceptor
+    {
+        /// <summary>
+        /// Gets state of <paramref name="item"/> based on <paramref name="relationshipType"/>.
+        /// </summary>
+        /// <param name="item">Current item.</param>
+        /// <param name="relationshipType">Relationship of current item.</param>
+        /// <returns>State of <paramref name="item"/> based on <paramref name="relationshipType"/>.</returns>
+        EntityState? GetEntityState(ITrackable item, RelationshipType? relationshipType);
+    }
+}
\ No newline at end of file
diff --git a/Source/TrackableEntities.EF.5/InterceptorExtensions.cs b/Source/TrackableEntities.EF.5/InterceptorExtensions.cs
new file mode 100644
index 00000000..caa9c59e
--- /dev/null
+++ b/Source/TrackableEntities.EF.5/InterceptorExtensions.cs
@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.Data.Entity;
+#if EF_6
+#else
+using System.Data;
+#endif
+
+#if EF_6
+namespace TrackableEntities.EF6
+#else
+namespace TrackableEntities.EF5
+#endif
+{
+    /// <summary>
+    /// Extension methods for <see cref="DbContext"/> and <see cref="InterceptorPool"/> with fluent API allowing
+    /// to add inteceptors (instances of <see cref="IStateInterceptor"/>) to <see cref="DbContextExtensions.ApplyChanges(DbContext, ITrackable)"/>.
+    /// </summary>
+    public static class InterceptorExtensions
+    {
+        /// <summary>
+        /// Injects interceptor implementing <see cref="IStateInterceptor"/> intto <see cref="DbContextExtensions.ApplyChanges(DbContext, ITrackable)"/>.
+        /// </summary>
+        /// <param name="dbContext"><see cref="DbContext"/> used to query and save changes to a database</param>
+        /// <param name="interceptor">Instance of <see cref="IStateInterceptor"/></param>
+        public static InterceptorPool WithInterceptor(this DbContext dbContext, IStateInterceptor interceptor)
+        {
+            var pool = new InterceptorPool(dbContext);
+            return WithInterceptor(pool, interceptor);
+        }
+
+        /// <summary>
+        /// Injects interceptor implementing <see cref="IStateInterceptor"/> into <see cref="DbContextExtensions.ApplyChanges(DbContext, ITrackable)"/>.
+        /// </summary>
+        /// <param name="pool">Pool of interceptors.</param>
+        /// <param name="interceptor">Instance of <see cref="IStateInterceptor"/></param>
+        public static InterceptorPool WithInterceptor(this InterceptorPool pool, IStateInterceptor interceptor)
+        {
+            pool.Interceptors.Add(interceptor);
+            return pool;
+        }
+
+        /// <summary>
+        /// Injects interceptor for setting explicitly the state of an entity into <see cref="DbContextExtensions.ApplyChanges(DbContext, ITrackable)"/>.
+        /// </summary>
+        /// <param name="dbContext"><see cref="DbContext"/> used to query and save changes to a database</param>
+        /// <param name="stateSelector">Used for setting state of entity.</param>
+        public static InterceptorPool WithStateChangeInterceptor<TEntity>(this DbContext dbContext,
+            Func<TEntity, RelationshipType?, EntityState?> stateSelector)
+            where TEntity : class, ITrackable
+        {
+            var pool = new InterceptorPool(dbContext);
+            return WithStateChangeInterceptor(pool, stateSelector);
+        }
+
+        /// <summary>
+        /// Injects interceptor for setting explicitly the state of an entity into <see cref="DbContextExtensions.ApplyChanges(DbContext, ITrackable)"/>.
+        /// </summary>
+        /// <param name="pool">Pool of interceptors</param>
+        /// <param name="stateSelector">Used for setting state of entity</param>
+        public static InterceptorPool WithStateChangeInterceptor<TEntity>(this InterceptorPool pool,
+            Func<TEntity, RelationshipType?, EntityState?> stateSelector)
+            where TEntity : class, ITrackable
+        {
+            pool.Interceptors.Add(new StateChangeInterceptor<TEntity>(stateSelector));
+            return pool;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Source/TrackableEntities.EF.5/InterceptorPool.cs b/Source/TrackableEntities.EF.5/InterceptorPool.cs
new file mode 100644
index 00000000..85c46a97
--- /dev/null
+++ b/Source/TrackableEntities.EF.5/InterceptorPool.cs
@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+using System.Data.Entity;
+
+#if EF_6
+namespace TrackableEntities.EF6
+#else
+namespace TrackableEntities.EF5
+#endif
+{
+    /// <summary>
+    /// Pool of interceptors.
+    /// </summary>
+    public class InterceptorPool
+    {
+        internal DbContext DbContext { get; private set; }
+        internal IList<IStateInterceptor> Interceptors { get; private set; }
+
+        internal InterceptorPool(DbContext dbContext)
+        {
+            DbContext = dbContext;
+            Interceptors = new List<IStateInterceptor>();
+        }
+    }
+}
\ No newline at end of file
diff --git a/Source/TrackableEntities.EF.5/RelationshipType.cs b/Source/TrackableEntities.EF.5/RelationshipType.cs
new file mode 100644
index 00000000..c50759f9
--- /dev/null
+++ b/Source/TrackableEntities.EF.5/RelationshipType.cs
@@ -0,0 +1,21 @@
+#if EF_6
+namespace TrackableEntities.EF6
+#else
+namespace TrackableEntities.EF5
+#endif
+{
+    /// <summary>
+    /// Type of relationship between entities.
+    /// </summary>
+    public enum RelationshipType
+    {
+        /// <summary>Many to one relationship.</summary>
+        ManyToOne,
+        /// <summary>One to one relationship.</summary>
+        OneToOne,
+        /// <summary>Many to many relationship.</summary>
+        ManyToMany,
+        /// <summary>One to many relationship.</summary>
+        OneToMany
+    }
+}
\ No newline at end of file
diff --git a/Source/TrackableEntities.EF.5/StateChangeInterceptor.cs b/Source/TrackableEntities.EF.5/StateChangeInterceptor.cs
new file mode 100644
index 00000000..87113e48
--- /dev/null
+++ b/Source/TrackableEntities.EF.5/StateChangeInterceptor.cs
@@ -0,0 +1,42 @@
+using System;
+#if EF_6
+using System.Data.Entity;
+#else
+using System.Data;
+#endif
+
+#if EF_6
+namespace TrackableEntities.EF6
+#else
+namespace TrackableEntities.EF5
+#endif
+{
+    /// <summary>
+    /// Interceptor for setting explicitly the state of an entity.
+    /// </summary>
+    /// <typeparam name="TEntity">Type of entity.</typeparam>
+    public class StateChangeInterceptor<TEntity> : IStateInterceptor where TEntity : class, ITrackable
+    {
+        private readonly Func<TEntity, RelationshipType?, EntityState?> _selector;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="T:StateChangeInterceptor"/> class.
+        /// </summary>
+        public StateChangeInterceptor(Func<TEntity, RelationshipType?, EntityState?> selector)
+        {
+            _selector = selector;
+        }
+
+        /// <summary>
+        /// Gets state of <paramref name="item"/> based on <paramref name="relationshipType"/>.
+        /// </summary>
+        /// <param name="item">Current item.</param>
+        /// <param name="relationshipType">Relationship of current item.</param>
+        /// <returns>State of <paramref name="item"/> based on <paramref name="relationshipType"/>.</returns>
+        public EntityState? GetEntityState(ITrackable item, RelationshipType? relationshipType)
+        {
+            var entity = item as TEntity;
+            return entity != null ? _selector(entity, relationshipType) : null;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Source/TrackableEntities.EF.5/TrackableEntities.EF.5.csproj b/Source/TrackableEntities.EF.5/TrackableEntities.EF.5.csproj
index acd954b8..94d66646 100644
--- a/Source/TrackableEntities.EF.5/TrackableEntities.EF.5.csproj
+++ b/Source/TrackableEntities.EF.5/TrackableEntities.EF.5.csproj
@@ -60,7 +60,14 @@
     </Compile>
     <Compile Include="Constants.cs" />
     <Compile Include="DbContextExtensions.cs" />
+    <Compile Include="Exceptions\RelationshipNotDeterminedException.cs" />
+    <Compile Include="Exceptions\TrackableEntitiesException.cs" />
+    <Compile Include="IStateInterceptor.cs" />
+    <Compile Include="InterceptorPool.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="RelationshipType.cs" />
+    <Compile Include="InterceptorExtensions.cs" />
+    <Compile Include="StateChangeInterceptor.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\TrackableEntities.Common\TrackableEntities.Common.csproj">
diff --git a/Source/TrackableEntities.EF.6/TrackableEntities.EF.6.csproj b/Source/TrackableEntities.EF.6/TrackableEntities.EF.6.csproj
index 2b207003..ed2d051f 100644
--- a/Source/TrackableEntities.EF.6/TrackableEntities.EF.6.csproj
+++ b/Source/TrackableEntities.EF.6/TrackableEntities.EF.6.csproj
@@ -67,6 +67,27 @@
     <Compile Include="..\TrackableEntities.EF.5\DbContextExtensions.cs">
       <Link>DbContextExtensions.cs</Link>
     </Compile>
+    <Compile Include="..\TrackableEntities.EF.5\Exceptions\RelationshipNotDeterminedException.cs">
+      <Link>Exceptions\RelationshipNotDeterminedException.cs</Link>
+    </Compile>
+    <Compile Include="..\TrackableEntities.EF.5\Exceptions\TrackableEntitiesException.cs">
+      <Link>Exceptions\TrackableEntitiesException.cs</Link>
+    </Compile>
+    <Compile Include="..\TrackableEntities.EF.5\InterceptorExtensions.cs">
+      <Link>InterceptorExtensions.cs</Link>
+    </Compile>
+    <Compile Include="..\TrackableEntities.EF.5\InterceptorPool.cs">
+      <Link>InterceptorPool.cs</Link>
+    </Compile>
+    <Compile Include="..\TrackableEntities.EF.5\IStateInterceptor.cs">
+      <Link>IStateInterceptor.cs</Link>
+    </Compile>
+    <Compile Include="..\TrackableEntities.EF.5\RelationshipType.cs">
+      <Link>RelationshipType.cs</Link>
+    </Compile>
+    <Compile Include="..\TrackableEntities.EF.5\StateChangeInterceptor.cs">
+      <Link>StateChangeInterceptor.cs</Link>
+    </Compile>
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/Source/TrackableEntities.sln.DotSettings b/Source/TrackableEntities.sln.DotSettings
deleted file mode 100644
index 4ad63523..00000000
--- a/Source/TrackableEntities.sln.DotSettings
+++ /dev/null
@@ -1,11 +0,0 @@
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-  <s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ArrangeModifiersOrder/@EntryIndexedValue">WARNING</s:String>
-  <s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ArrangeRedundantParentheses/@EntryIndexedValue">SUGGESTION</s:String>
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-	<s:String x:Key="/Default/CodeStyle/CSharpVarKeywordUsage/ForSimpleTypes/@EntryValue">UseVarWhenEvident</s:String>
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\ No newline at end of file