backbone routes constraint http://stackoverflow.com/questions/12082643/how-to-handle-non-root-urls-in-a-singlepage-app

routes.rb

class XHRConstraint
  def matches?(request)
    !request.xhr? && !(request.url =~ /\.json$/ && ::Rails.env == 'development')
  end
end

match '(*url)' => 'home#index', :constraints => XHRConstraint.new