How To: Make Devise work with other formats like mobile, iPhone and iPad (Rails specific)

1. Make your app render Apple iOS templates for iOS devices like iPhone, iPad, iPod Touch, etc. In the Rails app/controllers/application_controller.rb add this code:

  before_filter :adjust_format_for_iphone
  private
  def adjust_format_for_iphone    
    request.format = :ios if request.env["HTTP_USER_AGENT"] =~ %r{Mobile/.+Safari}
  end

2. Set Devise to display views for iOS In the config/initializers/devise.rb, look for the 'config.navigational_formats' and add every other formats you have config.navigational_formats = [:"*/*", "*/*", :html, :ios]

3. Create each view you need for Devise (login form, signup form, ...) Name your view like 'new.ios.erb' eg: 'app/views/devise/sessions/new.ios.erb' for login form

4. Create an initializer in the folder config/initializers Add this code into your initializer

ActionController::Responder.class_eval do
  alias :to_ios :to_html
end

This code has to correspond to your format (ie: :to_ios, :to_ipad, :to_mobile)

5. Add your format to config/initializers/mime_types.rb

Mime::Type.register_alias "text/html", :ios

6. Note that if you use OAUTH for Facebook you will need to configure it to use facebook's mobile authentication path. This post explains how.