polymorphic_relationships

Author: nduitz

lib/jsonapi/serializer.ex

@@ -80,7 +80,7 @@ defmodule JSONAPI.Serializer do
 
   @spec encode_relationships(Conn.t(), document(), tuple(), list()) :: tuple()
   def encode_relationships(conn, doc, {view, data, _, _} = view_info, options) do
-    view.relationships()
+    view.resource_relationships(data)
     |> Enum.filter(&assoc_loaded?(Map.get(data, get_data_key(&1))))
     |> Enum.map_reduce(doc, &build_relationships(conn, view_info, &1, &2, options))
   end

lib/jsonapi/view.ex

@@ -157,6 +157,9 @@ defmodule JSONAPI.View do
   @callback relationships() :: [
               {atom(), t() | {t(), :include} | {atom(), t()} | {atom(), t(), :include}}
             ]
+  @callback polymorphic_relationships(data()) :: [
+              {atom(), t() | {t(), :include} | {atom(), t()} | {atom(), t(), :include}}
+            ]
   @callback type() :: resource_type()
   @callback polymorphic_type(data()) :: resource_type()
   @callback url_for(data(), Conn.t() | nil) :: String.t()
@@ -259,6 +262,9 @@ defmodule JSONAPI.View do
       @impl View
       def relationships, do: []
 
+      @impl View
+      def polymorphic_relationships(_data), do: []
+
       cond do
         @resource_type ->
           @impl View
@@ -314,6 +320,14 @@ defmodule JSONAPI.View do
         end
       end
 
+      def resource_relationships(data) do
+        if @polymorphic_resource do
+          polymorphic_relationships(data)
+        else
+          relationships()
+        end
+      end
+
       defoverridable View
 
       def index(models, conn, _params, meta \\ nil, options \\ []),