comments: added comment to assign method

Author: maurei

src/JsonApiDotNetCore/Data/DefaultEntityRepository.cs

@@ -215,9 +215,6 @@ public void DetachRelationshipPointers(TEntity entity)
             }
         }
 
-
-
-
         /// <inheritdoc />
         public virtual async Task<TEntity> UpdateAsync(TId id, TEntity entity)
         {
@@ -247,12 +244,12 @@ public virtual async Task<TEntity> UpdateAsync(TId id, TEntity entity)
                     {
                         // load relations to enforce complete replace
                         await _context.Entry(oldEntity).Collection(hasManyAttribute.InternalRelationshipName).LoadAsync();
-                        // also need to load inverse relationship here, see issue #502
+                        // todo: need to load inverse relationship here, see issue #502
                         hasManyAttribute.SetValue(oldEntity, relationshipValue);
                     }
                     else if (relationshipEntry.Key is HasOneAttribute hasOneAttribute)
                     {
-                        // need to load inverse relationship here, see issue #502
+                        // todo: need to load inverse relationship here, see issue #502
                         hasOneAttribute.SetValue(oldEntity, relationshipValue);
                     }
                 }
@@ -261,22 +258,6 @@ public virtual async Task<TEntity> UpdateAsync(TId id, TEntity entity)
             return oldEntity;
         }
 
-        private void AssignHasManyThrough(TEntity entity, HasManyThroughAttribute hasManyThrough, IList relationshipValue)
-        {
-            var pointers = relationshipValue.Cast<IIdentifiable>();
-            var throughRelationshipCollection = Activator.CreateInstance(hasManyThrough.ThroughProperty.PropertyType) as IList;
-            hasManyThrough.ThroughProperty.SetValue(entity, throughRelationshipCollection);
-
-            foreach (var pointer in pointers)
-            {
-                var throughInstance = Activator.CreateInstance(hasManyThrough.ThroughType);
-                hasManyThrough.LeftProperty.SetValue(throughInstance, entity);
-                hasManyThrough.RightProperty.SetValue(throughInstance, pointer);
-                throughRelationshipCollection.Add(throughInstance);
-            }
-        }
-
-
         /// <inheritdoc />
         public async Task UpdateRelationshipsAsync(object parent, RelationshipAttribute relationship, IEnumerable<string> relationshipIds)
         {
@@ -422,7 +403,26 @@ private void AttachHasManyAndHasManyThroughPointers(TEntity entity)
             }
         }
 
+        /// <summary>
+        /// The relationshipValue parameter contains the dependent side of the relationship (Tags).
+        /// We can't directly add them to the principal entity (Article): we need to 
+        /// use the join table (ArticleTags). This methods assigns the relationship value to entity
+        /// by taking care of that
+        /// </summary>
+        protected void AssignHasManyThrough(TEntity entity, HasManyThroughAttribute hasManyThrough, IList relationshipValue)
+        {
+            var pointers = relationshipValue.Cast<IIdentifiable>();
+            var throughRelationshipCollection = Activator.CreateInstance(hasManyThrough.ThroughProperty.PropertyType) as IList;
+            hasManyThrough.ThroughProperty.SetValue(entity, throughRelationshipCollection);
 
+            foreach (var pointer in pointers)
+            {
+                var throughInstance = Activator.CreateInstance(hasManyThrough.ThroughType);
+                hasManyThrough.LeftProperty.SetValue(throughInstance, entity);
+                hasManyThrough.RightProperty.SetValue(throughInstance, pointer);
+                throughRelationshipCollection.Add(throughInstance);
+            }
+        }
 
         /// <summary>
         /// This is used to allow creation of HasOne relationships when the