ruby-on-rails – respond_to do | format | format.js无法正常

Rails 4.2.0

ruby 2.2(也尝试用4.0 …我降级为匹配设置为工作…)
控制台返回错误：

CameraController处理#显示为HTML
已完成406在2ms内无法接受

ActionController :: UnknownFormat(ActionController :: UnknownFormat)：

http://apidock.com/rails/Mime提到js是Rails的DEFAULT mime类型..我尝试将它添加到头文件但是在控制台中返回一条消息说我不需要将它包含在头文件中…我错过了什么？

#camera_controller.rb
class CameraController < ApplicationController
  # respond_to :js   #I have tried using this...
  def show
    respond_to do |format|
      format.js #{render 'show.js.erb'} #I have tried this too..
    end
  end
end

# 'home/sidebar.html.haml'
...
# =link_to "Menu Items",menu_items_index_path,:handlers => [:erb],:formats => [:js],remote:true
=link_to "Camera",camera_show_path,remote: true
...

# 'config/routes.rb'
...
get 'camera/show'
...


# camera/show.js.erb
$("#main_view").html("<%= escape_javascript(render :partial => 'camera/show')%>")