From https://once.com/writebook

app/controllers/concerns/book_scoped.rb

@@ -0,0 +1,14 @@
+module BookScoped extend ActiveSupport::Concern
+  included do
+    before_action :set_book
+  end
+
+  private
+    def set_book
+      @book = Book.accessable_or_published.find(params[:book_id])
+    end
+
+    def ensure_editable
+      head :forbidden unless @book.editable?
+    end
+end