Share instance data across objects/classes in a custom web app

I'm working on a rack web app from the ground up in Ruby and I want to be able to share th开发者_开发知识库e instances of several objects across all classes in the app. For example, the logger, the request information, a currently authenticated user, get/post parameters, etc.

To any of you familiar with PHP, I've accomplished this in the past with static variables, e.g. self::$params which gets shared across every instance of every class that inherits from the base class.

What's going to be the best way to accomplish this with ruby?

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the syntax is similar in ruby

$variable = value

the $ is the 'global' accessibility modifier in ruby. any code in your app that uses $variable will be accessing the variable data.

alternatively (my preferred method), you can use a class level method:

class MyClass
  def self.logger
    @logger
  end
end

then you can access this anywhere in your app using MyClass.logger

and third, you can specify a Constant as any value you want (as long as you don't want to change the value later).

MyContant = myvalue

anything that starts with a capital letter is a constant.