Return a boolean indicating favorite in party object

app/controllers/api/v1/parties_controller.rb

@@ -27,6 +27,7 @@ class Api::V1::PartiesController < Api::V1::ApiController
     end
 
     def show
+        @favorited = (current_user) ? @party.is_favorited(current_user) : false
         render_not_found_response if @party.nil?
     end
 

app/models/party.rb

@@ -7,4 +7,8 @@ class Party < ApplicationRecord
     has_many :characters, foreign_key: "party_id", class_name: "GridCharacter", dependent: :destroy
     has_many :weapons, foreign_key: "party_id", class_name: "GridWeapon", dependent: :destroy
     has_many :summons, foreign_key: "party_id", class_name: "GridSummon", dependent: :destroy
+
+    def is_favorited(user)
+        user.favorite_parties.include? self
+    end
 end

app/views/api/v1/parties/base.json.rabl

@@ -6,6 +6,10 @@ node :is_extra do |p|
     p.extra
 end
 
+node :is_favorite do |p|
+    @favorited
+end
+
 node :user do |p|
     partial('users/base', :object => p.user)
 end