From https://once.com/writebook

app/controllers/concerns/user_scoped.rb

@@ -0,0 +1,12 @@
+module UserScoped
+  extend ActiveSupport::Concern
+
+  included do
+    before_action :set_user
+  end
+
+  private
+    def set_user
+      @user = User.active.find(params[:user_id])
+    end
+end