Merge pull request ruby-grape#62 from AlexYankee/issue_with_nested_attributes

Issue with nested attributes

Author: dblock

lib/grape_entity/entity.rb

@@ -141,8 +141,8 @@ def self.expose(*args, &block)
         unless @nested_attributes.empty?
           attribute = "#{@nested_attributes.last}__#{attribute}"
           options[:nested] = true
-          nested_exposures[@nested_attributes.last.to_sym] ||= {}
-          nested_exposures[@nested_attributes.last.to_sym][attribute.to_sym] = options
+          nested_exposures_hash[@nested_attributes.last.to_sym] ||= {}
+          nested_exposures_hash[@nested_attributes.last.to_sym][attribute.to_sym] = options
         end
 
         exposures[attribute.to_sym] = options
@@ -184,14 +184,22 @@ def self.exposures
       @exposures
     end
 
-    def self.nested_exposures
-      @nested_exposures ||= {}
+    class << self
+      attr_accessor :_nested_exposures_hash
 
-      if superclass.respond_to? :nested_exposures
-        @nested_exposures = superclass.nested_exposures.merge(@nested_exposures)
+      def nested_exposures_hash
+        self._nested_exposures_hash ||= {}
       end
 
-      @nested_exposures
+      def nested_exposures
+        value = nested_exposures_hash
+
+        if superclass.respond_to? :nested_exposures
+          value = superclass.nested_exposures.merge(value)
+        end
+
+        value
+      end
     end
 
     # Returns a hash, the keys are symbolized references to fields in the entity,

spec/grape_entity/entity_spec.rb

@@ -130,6 +130,42 @@ class BogusEntity < Grape::Entity
             }
           end
 
+          it "complex nested attributes" do
+            class ClassRoom < Grape::Entity
+              expose(:parents, using: 'Parent') { |_| [{}, {}] }
+            end
+
+            class Person < Grape::Entity
+              expose :user do
+                expose(:id) { |_| 'value' }
+              end
+            end
+
+            class Student < Person
+              expose :user do
+                expose(:user_id) { |_| 'value' }
+                expose(:user_display_id, as: :display_id) { |_| 'value' }
+              end
+            end
+
+            class Parent < Person
+              expose(:children, using: 'Student') { |_| [{}, {}] }
+            end
+
+            ClassRoom.represent({}).serializable_hash.should == {
+              parents: [
+                {
+                  user: { id: "value" },
+                  children: [{ user: { user_id: "value", display_id: "value" } }, { user: { user_id: "value", display_id: "value" } }]
+                },
+                {
+                  user: { id: "value" },
+                  children: [{ user: { user_id: "value", display_id: "value" } }, { user: { user_id: "value", display_id: "value" } }]
+                }
+              ]
+            }
+          end
+
           it 'is safe if its nested exposures are safe' do
             subject.with_options safe: true do
               subject.expose :awesome do