Refine related_through

lib/jsonapi/active_relation_retrieval.rb

@@ -7,6 +7,10 @@ def find_related_ids(relationship, options)
     end
 
     module ClassMethods
+      def allowed_related_through
+        @allowed_related_through ||= [:inverse, :primary]
+      end
+
       def default_find_related_through(polymorphic = false)
         if polymorphic
           JSONAPI.configuration.default_find_related_through_polymorphic
@@ -125,6 +129,11 @@ def find_fragments(filters, options)
                                options: options)
 
         if options[:cache]
+          # When using caching the a two step process is used. First the records ids are retrieved and then the
+          # records are retrieved using the ids. Then the ids are used to query the database again to get the
+          # cache misses. In the second phase the records are not sorted or paginated and the `records_for_populate`
+          # method is used to ensure any dependent includes or custom database fields are calculated.
+
           # This alias is going to be resolve down to the model's table name and will not actually be an alias
           resource_table_alias = resource_klass._table_name
 
@@ -195,6 +204,10 @@ def find_fragments(filters, options)
             warn "Performance issue detected: `#{self.name.to_s}.records` returned non-normalized results in `#{self.name.to_s}.find_fragments`."
           end
         else
+          # When not using caching resources can be generated after querying. The `records_for_populate`
+          # method is merged in to ensure any dependent includes or custom database fields are calculated.
+          records = records.merge(records_for_populate(options))
+
           linkage_fields = []
 
           linkage_relationships.each do |linkage_relationship|
@@ -318,10 +331,16 @@ def _find_related_monomorphic_fragments_through_primary(source_fragments, relati
         resource_klass = relationship.resource_klass
         linkage_relationships = resource_klass.to_one_relationships_for_linkage(include_directives[:include_related])
 
-        sort_criteria = []
-        options[:sort_criteria].try(:each) do |sort|
-          field = sort[:field].to_s == 'id' ? resource_klass._primary_key : sort[:field]
-          sort_criteria << { field: field, direction: sort[:direction] }
+        # Do not sort the related_fragments. This can be keyed off `connect_source_identity` to indicate whether this
+        # is a related resource primary step vs. an include step.
+        sort_related_fragments = !connect_source_identity
+
+        if sort_related_fragments
+          sort_criteria = []
+          options[:sort_criteria].try(:each) do |sort|
+            field = sort[:field].to_s == 'id' ? resource_klass._primary_key : sort[:field]
+            sort_criteria << { field: field, direction: sort[:direction] }
+          end
         end
 
         join_manager = ActiveRelation::JoinManagerThroughPrimary.new(resource_klass: self,

lib/jsonapi/active_relation_retrieval_v09.rb

@@ -13,8 +13,12 @@ def records_for(relation_name)
     end
 
     module ClassMethods
+      def allowed_related_through
+        @allowed_related_through ||= [:model_includes]
+      end
+
       def default_find_related_through(polymorphic = false)
-        polymorphic ? :model : :model
+        polymorphic ? :model_includes : :model_includes
       end
 
       # Finds Resources using the `filters`. Pagination and sort options are used when provided

lib/jsonapi/active_relation_retrieval_v10.rb

@@ -7,6 +7,10 @@ def find_related_ids(relationship, options)
     end
 
     module ClassMethods
+      def allowed_related_through
+        @allowed_related_through ||= [:primary]
+      end
+
       def default_find_related_through(polymorphic = false)
         polymorphic ? :primary : :primary
       end

lib/jsonapi/configuration.rb

@@ -176,9 +176,12 @@ def initialize
       # Available strategies:
       # 'JSONAPI::ActiveRelationRetrieval' - A configurable retrieval strategy
       # 'JSONAPI::ActiveRelationRetrievalV09' - Retrieves resources using the v0.9.x approach. This uses rails'
-      # `includes` method to retrieve related models. This requires overriding the `records_for` method on the resource
-      # to control filtering of included resources.
-      # 'JSONAPI::ActiveRelationRetrievalV10' - Retrieves resources using the v0.10.x approach
+      #   `includes` method to retrieve related models. This requires overriding the `records_for` method on the
+      #   resource to control filtering of included resources.
+      # 'JSONAPI::ActiveRelationRetrievalV10' - Retrieves resources using the v0.10.x approach. While this is mostly
+      #   equivalent to using the default JSONAPI::ActiveRelationRetrieval strategy with the
+      #   `default_find_related_through` and `default_find_related_through_polymorphic` options set to `:primary`,
+      #   it does perform a two phased query to retrieve resources like v0.10.x. did and is therefore less efficient.
       # Custom - Specify the a custom retrieval strategy module name as a string
       # :none
       # :self