Using resource controller and namespace

app/controllers/admin/digitals_controller.rb

@@ -1,10 +0,0 @@
-class Admin::DigitalsController < Spree::Admin::ResourceController
-  
-  index.before do
-    @product = Product.find_by_permalink(params[:product_id])
-  end
-  
-  create.wants.html { redirect_to admin_product_digitals_url(@product) }
-  destroy.wants.html { redirect_to admin_product_digitals_url(@product) }
-  
-end

app/controllers/digitals_controller.rb

@@ -1,16 +0,0 @@
-class DigitalsController < Spree::BaseController
-
-  ssl_required :show
-
-  def show
-    link = DigitalLink.find_by_secret(params[:secret])
-    if link.present? and link.digital.attachment.present?
-      attachment = link.digital.attachment
-      if link.authorize! and File.file?(attachment.path)
-        send_file attachment.path :filename => attachment.original_filename, :type => attachment.content_type and return
-      end
-    end
-    render :unauthorized
-  end
-  
-end

app/controllers/spree/admin/digitals_controller.rb

@@ -0,0 +1,15 @@
+module Spree
+  class Admin::DigitalsController < Spree::Admin::ResourceController
+    belongs_to "spree/product", find_by: :permalink
+    
+    def load_resource
+      @object = @product = Product.find_by_permalink(params[:product_id])
+    end
+
+    
+    protected
+      def location_after_save
+        admin_product_digitals_url(@product)
+      end
+  end
+end

app/controllers/spree/digitals_controller.rb

@@ -0,0 +1,18 @@
+module Spree
+  class DigitalsController < Spree::BaseController
+  
+    ssl_required :show
+  
+    def show
+      link = DigitalLink.find_by_secret(params[:secret])
+      if link.present? and link.digital.attachment.present?
+        attachment = link.digital.attachment
+        if link.authorize! and File.file?(attachment.path)
+          send_file attachment.path :filename => attachment.original_filename, :type => attachment.content_type and return
+        end
+      end
+      render :unauthorized
+    end
+    
+  end
+end