ResponsivePreview

Rack Middleware gem that injects an iframe around the response for the purpose of testing responsive css at different breakpoints.

Usage

Define when the responsive preview is shown

class MyController < ApplicationController
  def wants_responsive_preview?
    # some condition to decide when to view the page in the responsive preview layout
  end
end

Provide a responsive preview layout

<!-- app/views/layouts/responsive_preview.html.erb -->

<!-- Add some other chrome for switching devices/iframe dimensions -->
<%= content_tag :iframe, '', srcdoc: yield %>
<%= responsive_preview_js %>