view variants support

[hksk]

• What were you trying to do?
  add a view variant, example:

$ ls -lah app/views/admin/courses
drwxr-xr-x  7 casa  staff   224B May  4 02:17 .
drwxr-xr-x  4 casa  staff   128B May  4 01:00 ..
-rw-r--r--  1 casa  staff   2.0K May  4 02:38 show+student.html.erb
-rw-r--r--  1 casa  staff   2.0K May  4 02:38 show.html.erb

• What did you end up with (logs, or, even better, example apps are great!)?
  currently in the main controller, cant pass a variant, seems variant: :value not works

# main controller
    def show
      render locals: {
        page: Administrate::Page::Show.new(dashboard, requested_resource)
      }
    end

so I implemented something like this in my generated controller

# generated controller
    def show 
      variant = ""
      if current_user.is_student
        variant = "+student"
      end
      page = Administrate::Page::Show
      render "show#{variant}", locals: {
          page: Administrate::Page::Show.new(dashboard, requested_resource)
      }
    end

I guess we can add some like

# main controller
    def show
     variant = ""
     if !request.variant.nil? 
       variant = "+#{request.variant.to_s}"
     end
      render render "show#{variant}"locals: {
        page: Administrate::Page::Show.new(dashboard, requested_resource)
      }
    end
# generated controller
    def show
      request.variant = :student
      super
    end