ruby - 如何使用（ruby）机架中间件组件设置 cookie？

Question

我正在为需要有条件地设置 cookie 的 rails 应用程序编写机架中间件组件。我目前正试图弄清楚设置cookies。从谷歌搜索看来，这应该可行：

class RackApp
  def initialize(app)
    @app = app
  end

  def call(env)
    @status, @headers, @response = @app.call(env)
    @response.set_cookie("foo", {:value => "bar", :path => "/", :expires => Time.now+24*60*60})
    [@status, @headers, @response]
  end
end

它不会给出错误，但也不会设置 cookie。我究竟做错了什么？

Answer 1

如果你想使用 Response 类，你需要从调用中间件层的结果进一步实例化它。此外，您不需要像这样的中间件的实例变量，并且可能不想以这种方式使用它们（@status 等会在服务请求后留在中间件实例中）

class RackApp
  def initialize(app)
    @app = app
  end

  def call(env)
    status, headers, body = @app.call(env)
    # confusingly, response takes its args in a different order
    # than rack requires them to be passed on
    # I know it's because most likely you'll modify the body, 
    # and the defaults are fine for the others. But, it still bothers me.

    response = Rack::Response.new body, status, headers

    response.set_cookie("foo", {:value => "bar", :path => "/", :expires => Time.now+24*60*60})
    response.finish # finish writes out the response in the expected format.
  end
end

如果您知道自己在做什么，如果您不想实例化新对象，则可以直接修改 cookie 标头。

Answer 2

您还可以使用该Rack::Utils库来设置和删除标头，而无需创建 Rack::Response 对象。

class RackApp
  def initialize(app)
    @app = app
  end

  def call(env)
    status, headers, body = @app.call(env)

    Rack::Utils.set_cookie_header!(headers, "foo", {:value => "bar", :path => "/"})

    [status, headers, body]
  end
end