first pass at deeply nested inclusion implementation

Author: jaredcnance

src/JsonApiDotNetCore/Builders/DocumentBuilder.cs

@@ -192,20 +192,35 @@ private RelationshipData GetRelationshipData(RelationshipAttribute attr, Context
             return relationshipData;
         }
 
-        private List<DocumentData> GetIncludedEntities(List<DocumentData> included, ContextEntity contextEntity, IIdentifiable entity)
+        private List<DocumentData> GetIncludedEntities(List<DocumentData> included, ContextEntity rootContextEntity, IIdentifiable rootResource)
         {
-            contextEntity.Relationships.ForEach(r =>
+            if(_jsonApiContext.IncludedRelationships != null)
             {
-                if (!RelationshipIsIncluded(r.PublicRelationshipName)) return;
-
-                var navigationEntity = _jsonApiContext.ContextGraph.GetRelationship(entity, r.InternalRelationshipName);
-
-                if (navigationEntity is IEnumerable hasManyNavigationEntity)
-                    foreach (IIdentifiable includedEntity in hasManyNavigationEntity)
-                        included = AddIncludedEntity(included, includedEntity);
-                else
-                    included = AddIncludedEntity(included, (IIdentifiable)navigationEntity);
-            });
+                foreach(var relationshipName in _jsonApiContext.IncludedRelationships)
+                {
+                    var relationshipChain = relationshipName.Split('.');
+
+                    var contextEntity = rootContextEntity;
+                    var entity = rootResource;
+
+                    for(var i = 0; i < relationshipChain.Length; i++)
+                    {
+                        var requestedRelationship = relationshipChain[i];
+                        var relationship = contextEntity.Relationships.FirstOrDefault(r => r.PublicRelationshipName == requestedRelationship);
+                        var navigationEntity = _jsonApiContext.ContextGraph.GetRelationship(entity, relationship.InternalRelationshipName);
+                        if (navigationEntity is IEnumerable hasManyNavigationEntity)
+                            foreach (IIdentifiable includedEntity in hasManyNavigationEntity)
+                                included = AddIncludedEntity(included, includedEntity);
+                        else
+                            included = AddIncludedEntity(included, (IIdentifiable)navigationEntity);
+                        
+                        if(i < relationshipChain.Length) {
+                            contextEntity = _jsonApiContext.ContextGraph.GetContextEntity(relationship.Type);
+                            entity = (IIdentifiable)navigationEntity; // HACK: only handles HasOne case ...
+                        }
+                    }
+                }                
+            }
 
             return included;
         }
@@ -245,12 +260,6 @@ private DocumentData GetIncludedEntity(IIdentifiable entity)
             return data;
         }
 
-        private bool RelationshipIsIncluded(string relationshipName)
-        {
-            return _jsonApiContext.IncludedRelationships != null &&
-                _jsonApiContext.IncludedRelationships.Contains(relationshipName);
-        }
-
         private List<ResourceIdentifierObject> GetRelationships(IEnumerable<object> entities)
         {
             var objType = entities.GetElementType();

src/JsonApiDotNetCore/Data/DefaultEntityRepository.cs

@@ -203,20 +203,38 @@ public virtual async Task<bool> DeleteAsync(TId id)
         /// <inheritdoc />
         public virtual IQueryable<TEntity> Include(IQueryable<TEntity> entities, string relationshipName)
         {
+            if(string.IsNullOrWhiteSpace(relationshipName)) throw new JsonApiException(400, "Include parameter must not be empty if provided");
+
+            var relationshipChain = relationshipName.Split('.');
+
+            // variables mutated in recursive loop
+            // TODO: make recursive method
+            string internalRelationshipPath = null;
             var entity = _jsonApiContext.RequestEntity;
-            var relationship = entity.Relationships.FirstOrDefault(r => r.PublicRelationshipName == relationshipName);
-            if (relationship == null)
+            for(var i = 0; i < relationshipChain.Length; i++)
             {
-                throw new JsonApiException(400, $"Invalid relationship {relationshipName} on {entity.EntityName}",
-                    $"{entity.EntityName} does not have a relationship named {relationshipName}");
-            }
+                var requestedRelationship = relationshipChain[i];
+                var relationship = entity.Relationships.FirstOrDefault(r => r.PublicRelationshipName == requestedRelationship);
+                if (relationship == null)
+                {
+                    throw new JsonApiException(400, $"Invalid relationship {requestedRelationship} on {entity.EntityName}",
+                        $"{entity.EntityName} does not have a relationship named {requestedRelationship}");
+                }
 
-            if (!relationship.CanInclude)
-            {
-                throw new JsonApiException(400, $"Including the relationship {relationshipName} on {entity.EntityName} is not allowed");
+                if (relationship.CanInclude == false)
+                {
+                    throw new JsonApiException(400, $"Including the relationship {requestedRelationship} on {entity.EntityName} is not allowed");
+                }
+
+                internalRelationshipPath = (internalRelationshipPath == null)
+                    ? relationship.InternalRelationshipName
+                    : $"{internalRelationshipPath}.{relationship.InternalRelationshipName}";
+                
+                if(i < relationshipChain.Length)
+                    entity = _jsonApiContext.ContextGraph.GetContextEntity(relationship.Type);
             }
 
-            return entities.Include(relationship.InternalRelationshipName);
+            return entities.Include(internalRelationshipPath);
         }
 
         /// <inheritdoc />

src/JsonApiDotNetCore/Models/RelationshipAttribute.cs

@@ -54,6 +54,11 @@ public bool TryGetHasMany(out HasManyAttribute result)
 
         public abstract void SetValue(object entity, object newValue);
 
+        public object GetValue(object entity) => entity
+            ?.GetType()
+            .GetProperty(InternalRelationshipName)
+            .GetValue(entity);
+
         public override string ToString()
         {
             return base.ToString() + ":" + PublicRelationshipName;

src/JsonApiDotNetCore/Serialization/JsonApiDeSerializer.cs

@@ -214,6 +214,15 @@ private object SetHasOneRelationship(object entity,
             SetHasOneForeignKeyValue(entity, attr, foreignKeyProperty, rio);
             SetHasOneNavigationPropertyValue(entity, attr, rio, included);
 
+            // recursive call ...
+            var navigationPropertyValue = attr.GetValue(entity);
+            var contextGraphEntity = _jsonApiContext.ContextGraph.GetContextEntity(attr.Type);
+            if(navigationPropertyValue != null && contextGraphEntity != null)
+            {
+                var includedResource = included.Single(r => r.Type == rio.Type && r.Id == rio.Id);
+                SetRelationships(navigationPropertyValue, contextGraphEntity, includedResource.Relationships, included);
+            }
+
             return entity;
         }
 

src/JsonApiDotNetCore/Services/QueryParser.cs

@@ -179,10 +179,6 @@ protected virtual List<SortQuery> ParseSortParameters(string value)
 
         protected virtual List<string> ParseIncludedRelationships(string value)
         {
-            const string NESTED_DELIMITER = ".";
-            if (value.Contains(NESTED_DELIMITER))
-                throw new JsonApiException(400, "Deeply nested relationships are not supported");
-
             return value
                 .Split(QueryConstants.COMMA)
                 .ToList();