Ruby 列出Rails控制器实例变量
我试图在一个控制器中列出实例变量,但是我想到了Ruby 列出Rails控制器实例变量,ruby,ruby-on-rails-3,metaprogramming,Ruby,Ruby On Rails 3,Metaprogramming,我试图在一个控制器中列出实例变量,但是我想到了 irb>HomeController.instance_variable_names => ["@visible_actions", "@inheritable_attributes", "@controller_path", "@action_methods", "@_process_action_callbacks"] 我试过了 irb>HomeController.action("index").instance_vari
irb>HomeController.instance_variable_names
=> ["@visible_actions", "@inheritable_attributes", "@controller_path", "@action_methods", "@_process_action_callbacks"]
我试过了
irb>HomeController.action("index").instance_variable_names
=> []
那么控制器实例变量属于什么呢?实例变量属于实例化的控制器对象,并且仅在执行操作方法时创建。试试这个:
irb>instantiated_controller = HomeController.new
irb>instantiated_controller.index
irb>instantiated_controller.instance_variable_names
=> ["@_status", "@_headers", ...
您还可以直接从控制器代码调用
self.instance\u variable\u name
,然后在日志中查看它们
class ProfilesController < ApplicationController
...
def update
logger.info("List of instance vars: #{self.instance_variable_names}")
...
end
end
class ProfilesController