ruby-on-rails - 未定义的方法 `content_type' 为 nil :NilClass

Question

Diagnostics.erb 文件中关于 _set_controller_content_type 的奇怪错误.

请帮忙。

NoMethodError in Timelines#public_timeline

Showing /opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/templates/rescues/diagnostics.erb where line # raised:

undefined method `content_type' for nil:NilClass
Extracted source (around line #):

RAILS_ROOT: /Volumes/DATA/Source/Rails/tvider

Application Trace | Framework Trace | Full Trace
/opt/local/lib/ruby1.9/gems/1.9.1/gems/activesupport-2.3.5/lib/active_support/whiny_nil.rb:52:in `method_missing'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_view/base.rb:331:in `_set_controller_content_type'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_view/renderable.rb:32:in `block in render'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_view/base.rb:306:in `with_template'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_view/renderable.rb:30:in `render'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_view/template.rb:205:in `render_template'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_view/base.rb:265:in `render'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:134:in `rescue_action_locally'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:152:in `rescue_action_without_handler'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:74:in `rescue_action'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:162:in `rescue in perform_action_with_rescue'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:160:in `perform_action_with_rescue'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/flash.rb:146:in `perform_action_with_flash'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in `process'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/filters.rb:606:in `process_with_filters'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/base.rb:391:in `process'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/base.rb:386:in `call'
/opt/local/lib/ruby1.9/gems/1.9.1/gems/actionpack-2.3.5/lib/action_controller/routing/route_set.rb:437:in `call'
Request

Parameters:

None
Show session dump

Response

Headers:

{"Cache-Control"=>"no-cache",
 "Content-Type"=>""}

Answer 1

我不知道这是否是您错误的原因。但是当我收到这个错误时，那是因为我不假思索地在我的 Controller 中定义了一个“响应” Action 。重命名了 Action ，一切都很好。
代码示例:

class PagesController < ApplicationController

  def request
  end

  def response
  end

end