Add a cache buster in a Rails controller action only for XHR requests

rails_controller_cache_buster_xhr_request

class MyController < ApplicationController  
  
  def action_xyz
    if request.xhr?
      set_cache_buster
    end
    
    render json: {what: 'ever'}
  end

  private 

  # See: http://stackoverflow.com/a/748646/386517

    def set_cache_buster
      response.headers["Cache-Control"] = "no-cache, no-store, max-age=0, must-revalidate"
      response.headers["Pragma"] = "no-cache"
      response.headers["Expires"] = "Fri, 01 Jan 1990 00:00:00 GMT"
    end
end