Synced Marr with upstream

Marr.Data/DataMapper.cs

@@ -660,15 +660,19 @@ namespace Marr.Data
                         // and multiple entities are created from each view record.
                         foreach (EntityGraph lvl in graph)
                         {
-                            // If is child relationship entity, and childrenToLoad are specified, and entity is not listed,
-                            // then skip this entity.
-                            if (childrenToLoad.Count > 0 && !lvl.IsRoot && !childrenToLoad.ContainsMember(lvl.Member)) // lvl.Member.Name
+                            if (lvl.IsParentReference)
                             {
+                                // A child specified a circular reference to its previously loaded parent
+                                lvl.AddParentReference();
+                            }
+                            else if (childrenToLoad.Count > 0 && !lvl.IsRoot && !childrenToLoad.ContainsMember(lvl.Member))
+                            {
+                                // A list of relationships-to-load was specified and this relationship was not included
                                 continue;
                             }
-
-                            if (lvl.IsNewGroup(reader))
+                            else if (lvl.IsNewGroup(reader))
                             {
+                                // Create a new entity with the data reader
                                 var newEntity = mappingHelper.CreateAndLoadEntity(lvl.EntityType, lvl.Columns, reader, true);
 
                                 // Add entity to the appropriate place in the object graph

Marr.Data/EntityGraph.cs

@@ -43,7 +43,8 @@ namespace Marr.Data
         private GroupingKeyCollection _groupingKeyColumns;
         private Dictionary<string, EntityReference> _entityReferences;
 
-        public IList RootList { get; private set; }
+        internal IList RootList { get; private set; }
+        internal bool IsParentReference { get; private set; }
 
         /// <summary>
         /// Recursively builds an entity graph of the given parent type.
@@ -68,12 +69,22 @@ namespace Marr.Data
             _entityType = entityType;
             _parent = parent;
             _relationship = relationship;
+            IsParentReference = !IsRoot && AnyParentsAreOfType(entityType);
+            if (!IsParentReference)
+            {
                 _columns = _repos.GetColumns(entityType);
+            }
+            
             _relationships = _repos.GetRelationships(entityType);
             _children = new List<EntityGraph>();
             Member = relationship != null ? relationship.Member : null;
             _entityReferences = new Dictionary<string, EntityReference>();
 
+            if (IsParentReference)
+            {
+                return;
+            }
+
             // Create a new EntityGraph for each child relationship that is not lazy loaded
             foreach (Relationship childRelationship in this.Relationships)
             {
@@ -183,51 +194,12 @@ namespace Marr.Data
         }
 
         /// <summary>
-        /// Initializes the owning lists on many-to-many Children.
-        /// </summary>
-        /// <param name="entityInstance"></param>
-        private void InitOneToManyChildLists(EntityReference entityRef)
-        {
-            // Get a reference to the parent's the childrens' OwningLists to the parent entity
-            for (int i = 0; i < Relationships.Count; i++)
-            {
-                Relationship relationship = Relationships[i];
-                if (relationship.RelationshipInfo.RelationType == RelationshipTypes.Many)
-                {
-                    try
-                    {
-                        IList list = (IList)_repos.ReflectionStrategy.CreateInstance(relationship.MemberType);
-                        _repos.ReflectionStrategy.SetFieldValue(entityRef.Entity, relationship.Member.Name, list);
-                        
-                        // Save a reference to each 1-M list
-                        entityRef.AddChildList(relationship.Member.Name, list);
-                    }
-                    catch (Exception ex)
-                    {
-                        throw new DataMappingException(
-                            string.Format("{0}.{1} is a \"Many\" relationship type so it must derive from IList.",
-                                entityRef.Entity.GetType().Name, relationship.Member.Name),
-                            ex);
-                    }
-                }
-            }
-        }
-
-        /// <summary>
-        /// Recursively adds primary key columns from contiguous child graphs with a one-to-one relationship type to the pKeys collection..
+        /// Searches for a previously loaded parent entity and then sets that reference to the mapped Relationship property.
         /// </summary>
-        /// <param name="pKeys"></param>
-        /// <param name="entity"></param>
-        private void AddOneToOneChildKeys(ColumnMapCollection pKeys, EntityGraph entity)
-        {
-            var oneToOneChildren = entity.Children
-                .Where(c => c._relationship.RelationshipInfo.RelationType == RelationshipTypes.One);
-
-            foreach (var child in oneToOneChildren)
+        public void AddParentReference()
         {
-                pKeys.AddRange(child.Columns.PrimaryKeys);
-                AddOneToOneChildKeys(pKeys, child);
-            }
+            var parentReference = FindParentReference();
+            _repos.ReflectionStrategy.SetFieldValue(_parent._entity, _relationship.Member.Name, parentReference);
         }
         
         /// <summary>
@@ -278,6 +250,68 @@ namespace Marr.Data
             }
         }
 
+        private bool AnyParentsAreOfType(Type type)
+        {
+            EntityGraph parent = _parent;
+            while (parent != null)
+            {
+                if (parent._entityType == type)
+                {
+                    return true;
+                }
+                parent = parent._parent;
+            }
+
+            return false;
+        }
+
+        private object FindParentReference()
+        {
+            var parent = this.Parent.Parent;
+            while (parent != null)
+            {
+                if (parent._entityType == _relationship.MemberType)
+                {
+                    return parent._entity;
+                }
+
+                parent = parent.Parent;
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Initializes the owning lists on many-to-many Children.
+        /// </summary>
+        /// <param name="entityInstance"></param>
+        private void InitOneToManyChildLists(EntityReference entityRef)
+        {
+            // Get a reference to the parent's the childrens' OwningLists to the parent entity
+            for (int i = 0; i < Relationships.Count; i++)
+            {
+                Relationship relationship = Relationships[i];
+                if (relationship.RelationshipInfo.RelationType == RelationshipTypes.Many)
+                {
+                    try
+                    {
+                        IList list = (IList)_repos.ReflectionStrategy.CreateInstance(relationship.MemberType);
+                        _repos.ReflectionStrategy.SetFieldValue(entityRef.Entity, relationship.Member.Name, list);
+                        
+                        // Save a reference to each 1-M list
+                        entityRef.AddChildList(relationship.Member.Name, list);
+                    }
+                    catch (Exception ex)
+                    {
+                        throw new DataMappingException(
+                            string.Format("{0}.{1} is a \"Many\" relationship type so it must derive from IList.",
+                                entityRef.Entity.GetType().Name, relationship.Member.Name),
+                            ex);
+                    }
+                }
+            }
+        }
+
         /// <summary>
         /// Gets a list of keys to group by.
         /// </summary>

Marr.Data/Marr.Data.csproj

@@ -12,10 +12,6 @@
     <AssemblyName>Marr.Data</AssemblyName>
     <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
-    <SccProjectName>SAK</SccProjectName>
-    <SccLocalPath>SAK</SccLocalPath>
-    <SccAuxPath>SAK</SccAuxPath>
-    <SccProvider>SAK</SccProvider>
     <FileUpgradeFlags>
     </FileUpgradeFlags>
     <OldToolsVersion>3.5</OldToolsVersion>