如何在中间件中设置在我所有应用程序中均可访问的变量? [英] How to set in a middleware a variable accessible in all my application?

问题描述

我正在使用Ruby on Rails 3，并且尝试使用中间件来设置变量@variable_name，以后可以在控制器中访问.

I am using Ruby on Rails 3 and I am trying to use middlewares in order to set a variable @variable_name accessible later in controllers.

例如我的中间件是

  class Auth

    def initialize(app)
      @app = app
    end

    def call(env)
      @account ||= Account.find(1)

      @app.call(env)
    end
  end

上面的代码正确设置了@account变量，但是在我的应用程序中不可用(在控制器，模型，视图等中).所以，我该怎么做?

The above code set properly the @account variable, but that isn't available in my application (in controllers, models, views, ...). So, how can I accomplish that?

我看到了

I seen this answer that is a way to do what I need, but I would like to have the @account variable "directly accessible". That is, without use that way but making that available, for example in my views, like this:

<%= debug @account %>

推荐答案

您可以为此使用'env'.因此，在您的中间件中，您可以执行以下操作:

You can use 'env' for that. So in your middleware you do this:

def call(env)
  env['account'] = Account.find(1)
  @app.call(env)
end

您可以通过在应用程序中使用请求"来获得价值:

You can get the value by using 'request' in your app:

request.env['account']

请不要使用某些人在此处建议的全局变量或类属性.这是使自己陷入困境的肯定方法，而且确实是一种坏习惯.

And please don't use global variables or class attributes as some people suggest here. That's a sure way to get yourself into troubles and really is a bad habit.

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