rails没有检测到ajax请求

Question

我正在尝试在rails app中检测jquery发出的ajax请求。

下面是我在控制器中的代码 要求“openssl” 要求'消化/ sha2' 要求'base64'

class IndexController < ApplicationController
  def index

    if params['_escaped_fragment_'] == '/Home' or params['_escaped_fragment_'] == '/home'
      redirect_to :controller=>'crawler', :action => 'crawlhome'
      return false
    elsif params['_escaped_fragment_'] == '/Tv-Listings'
      redirect_to :controller=>'crawler', :action => 'crawltvlistings'
      return false
    elsif params['_escaped_fragment_'] == '/Movies'
      redirect_to :controller=>'crawler', :action => 'crawlmovies'
      return false
    elsif params['_escaped_fragment_'] == '/Videos' or params['_escaped_fragment_'] == '/videos'
      redirect_to :controller=>'crawler', :action => 'crawlvideos'
      return false
    elsif params['_escaped_fragment_'] == '/Channels' or params['_escaped_fragment_'] == '/channels'
      redirect_to :controller=>'crawler', :action => 'crawlchannels'
      return false
    elsif params['_escaped_fragment_'] == '/Mobile-Apps' or params['_escaped_fragment_'] == '/apps'
      redirect_to :controller=>'crawler', :action => 'crawlmobileapps'
      return false
    elsif params['_escaped_fragment_'] =~ /\/actor(.*)/
      redirect_to :controller=>'crawler', :action => 'crawlactor' , :actorname => params['_escaped_fragment_'].split("/").last
      return false
    elsif params['_escaped_fragment_'] =~ /\/program(.*)/
      redirect_to :controller=>'crawler', :action => 'crawlprogram' , :programename => params['_escaped_fragment_'].split("/").last
      return false
    elsif params['_escaped_fragment_'] =~ /\/channel(.*)/
      redirect_to :controller=>'crawler', :action => 'crawlchannel', :channelname => params['_escaped_fragment_'].split("/").last
      return false
    end


    if !request.xhr?  // want to execute this code only when request is not ajax
      @alg = "AES-256-CBC"
      aes = OpenSSL::Cipher::Cipher.new(@alg)
      aes.encrypt
      key = aes.random_key
      @pki = Base64.encode64(key).gsub(/\n/, '')
      session[:key] = key  
    end

end
end

但在我的情况下是request.xhr？总是返回nil或0。 请帮忙