From 6fdef6443b3a89f772f98039b252804ad6c47a50 Mon Sep 17 00:00:00 2001
From: Steve Wilkes <steve@agileobjects.co.uk>
Date: Tue, 9 May 2017 19:00:57 +0100
Subject: [PATCH] Support for populating nested context Target objects for
 post-mapping callbacks, re: issue #15

---
 .../WhenConfiguringMappingCallbacks.cs        | 52 ++++++++++++-------
 .../MappingExpressionFactoryBase.cs           |  6 ++-
 2 files changed, 38 insertions(+), 20 deletions(-)

diff --git a/AgileMapper.UnitTests/Configuration/WhenConfiguringMappingCallbacks.cs b/AgileMapper.UnitTests/Configuration/WhenConfiguringMappingCallbacks.cs
index a139db0c2..dac3a5dcc 100644
--- a/AgileMapper.UnitTests/Configuration/WhenConfiguringMappingCallbacks.cs
+++ b/AgileMapper.UnitTests/Configuration/WhenConfiguringMappingCallbacks.cs
@@ -56,8 +56,7 @@ public void ShouldExecuteAPreMappingCallbackForASpecifiedTargetTypeConditionally
         {
             using (var mapper = Mapper.CreateNew())
             {
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .To<Person>()
                     .Before
                     .MappingBegins
@@ -87,8 +86,7 @@ public void ShouldExecutePreAndPostMappingCallbacksForASpecifiedMember()
                 var preMappingName = default(string);
                 var postMappingName = default(string);
 
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .From<Person>()
                     .Over<PersonViewModel>()
                     .Before
@@ -116,8 +114,7 @@ public void ShouldExecuteAPreMemberMappingCallbackConditionally()
             {
                 var mappedTargetId = default(Guid);
 
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .From<Person>()
                     .ToANew<Person>()
                     .Before
@@ -145,8 +142,7 @@ public void ShouldExecuteAPostMemberMappingCallbackConditionally()
                 var mappedAddress = default(Address);
                 var callbackCalled = false;
 
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .ToANew<Person>()
                     .After
                     .Mapping(p => p.Address)
@@ -194,8 +190,7 @@ public void ShouldRestrictAPreMappingCallbackByTargetType()
         {
             using (var mapper = Mapper.CreateNew())
             {
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .To<PublicField<string>>()
                     .Before
                     .MappingBegins
@@ -219,8 +214,7 @@ public void ShouldRestrictAPreMappingCallbackBySourceTypeConditionally()
         {
             using (var mapper = Mapper.CreateNew())
             {
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .From<PublicProperty<string>>()
                     .To<PublicField<string>>()
                     .Before
@@ -245,8 +239,7 @@ public void ShouldExecuteAPostMappingCallbackForASpecifiedTargetTypeConditionall
         {
             using (var mapper = Mapper.CreateNew())
             {
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .To<PersonViewModel>()
                     .After
                     .MappingEnds
@@ -274,8 +267,7 @@ public void ShouldRestrictAPostMappingCallbackByTargetType()
         {
             using (var mapper = Mapper.CreateNew())
             {
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .To<PublicProperty<string>>()
                     .After
                     .MappingEnds
@@ -299,8 +291,7 @@ public void ShouldRestrictAPostMappingCallbackBySourceType()
         {
             using (var mapper = Mapper.CreateNew())
             {
-                mapper
-                    .WhenMapping
+                mapper.WhenMapping
                     .From<PublicField<string>>()
                     .To<PublicProperty<string>>()
                     .After
@@ -338,5 +329,30 @@ public void ShouldExecuteAPostMappingCallbackForADerivedType()
                 derivedSource.ShouldBeSameAs(source);
             }
         }
+
+        // See https://github.com/agileobjects/AgileMapper/issues/15
+        [Fact]
+        public void ShouldPopulateAChildTargetObjectInAPostMappingCallback()
+        {
+            using (var mapper = Mapper.CreateNew())
+            {
+                mapper.WhenMapping
+                    .From<PublicProperty<string>>()
+                    .To<PublicField<string>>()
+                    .After
+                    .MappingEnds
+                    .Call(ctx => ctx.Target.Value += "!");
+
+                var source = new PublicField<PublicProperty<string>>
+                {
+                    Value = new PublicProperty<string> { Value = "Hello" }
+                };
+
+                var result = mapper.Map(source).ToANew<PublicProperty<PublicField<string>>>();
+
+                result.Value.ShouldNotBeNull();
+                result.Value.Value.ShouldBe("Hello!");
+            }
+        }
     }
 }
diff --git a/AgileMapper/ObjectPopulation/MappingExpressionFactoryBase.cs b/AgileMapper/ObjectPopulation/MappingExpressionFactoryBase.cs
index d88d0adf8..21482116a 100644
--- a/AgileMapper/ObjectPopulation/MappingExpressionFactoryBase.cs
+++ b/AgileMapper/ObjectPopulation/MappingExpressionFactoryBase.cs
@@ -42,11 +42,13 @@ public Expression Create(IObjectMappingData mappingData)
             }
 
             var basicMapperData = mapperData.WithNoTargetMember();
+            var preMappingCallback = GetMappingCallbackOrNull(CallbackPosition.Before, basicMapperData, mapperData);
+            var postMappingCallback = GetMappingCallbackOrNull(CallbackPosition.After, basicMapperData, mapperData);
 
             mappingExpressions.AddUnlessNullOrEmpty(derivedTypeMappings);
-            mappingExpressions.AddUnlessNullOrEmpty(GetMappingCallbackOrNull(CallbackPosition.Before, basicMapperData, mapperData));
+            mappingExpressions.AddUnlessNullOrEmpty(preMappingCallback);
             mappingExpressions.AddRange(GetObjectPopulation(mappingData));
-            mappingExpressions.AddUnlessNullOrEmpty(GetMappingCallbackOrNull(CallbackPosition.After, basicMapperData, mapperData));
+            mappingExpressions.AddUnlessNullOrEmpty(postMappingCallback);
 
             var mappingBlock = GetMappingBlock(mappingExpressions, mapperData);
             var mappingBlockWithTryCatch = WrapInTryCatch(mappingBlock, mapperData);