Question

i’ve generated the devise views using rails g devise:views and then also followed the instructions to add the web-app-theme to sign but devise does not use that layout.

how you I change the devise layout to use web-app-theme?

Answer 1

You need to create a new layout file, specifically for logging in.

- app
   - views
     - layouts
       application.html.erb
       - devise
         sessions.html.erb

So you have your application layout file, but you also have a folder called devise, and in it, is a layout file for devise sessions. Rails should automatically pick up this layout and use it since it is the same path and name as the view being displayed (views/devise/sessions) so it’ll look for views/layouts/devise/sessions, and if it doesn’t find it, it’ll check if it’s defined elsewhere.

UPDATE

Here’s another potential solution I found on Stackoverflow.

Integrate layouts with Devise

UPDATE 2

A third option is to do what the devise wiki says.
How To: Create Custom Layouts