Cards inherit their collection's publication status

app/controllers/concerns/public_card_scoped.rb

@@ -0,0 +1,13 @@
+module PublicCardScoped
+  extend ActiveSupport::Concern
+
+  included do
+    before_action :set_collection_and_card
+  end
+
+  private
+    def set_collection_and_card
+      @collection = Collection.find_by_published_key(params[:collection_id])
+      @card = @collection.cards.find(params[:id])
+    end
+end

app/controllers/public/cards_controller.rb

@@ -0,0 +1,12 @@
+class Public::CardsController < ApplicationController
+  include PublicCardScoped
+
+  allow_unauthenticated_access only: :show
+
+  layout "public"
+
+  def show
+    # To enable caching at intermediate proxies during traffic spikes
+    expires_in 5.seconds, public: true
+  end
+end

config/routes.rb

@@ -134,6 +134,8 @@ Rails.application.routes.draw do
       scope module: :collections do
         resources :card_previews
       end
+
+      resources :cards, only: :show
     end
   end
 
@@ -141,6 +143,10 @@ Rails.application.routes.draw do
     route_for :public_collection, collection.publication.key
   end
 
+  direct :published_card do |card, options|
+    route_for :public_collection_card, card.collection.publication.key, card
+  end
+
   resolve "Card" do |card, options|
     route_for :collection_card, card.collection, card, options
   end