WIP

app/models/concerns/imageable.rb

@@ -0,0 +1,14 @@
+# can [:update, :destroy ], Image, :imageable_id => user.id, :imageable_type => 'User'
+# and add a feature like forbidden/without_role_images_spec.rb to test it
+module Imageable
+  extend ActiveSupport::Concern
+
+  included do
+    has_one :image, as: :imageable, dependent: :destroy
+    accepts_nested_attributes_for :image, allow_destroy: true
+
+    def image_url(style)
+      image.attachment.url(style) if image && image.attachment.exists?
+    end
+  end
+end