Detect in Rails after_filter whether we're rendering or redirecting

I'm writing 开发者_运维百科an after_filter in Rails 3, and I'd like to detect whether or not the controller (or any other filter) has issued a redirect. Is there any way to do this?

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You could look at the status code. 200 is a render, 302 is a redirect.

after_filter :what_happened

protected

def what_happened
  was_redirect = self.status == 302
  was_render = self.status == 200
end

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For anyone who is still stuck on rails 3, and wants to use a class based filter to share the logic between controllers with composition, check out the following example:

class MyController < ApplicationController
  after_filter ControllerMetrics
end

class ControllerMetrics
  def self.filter(controller)
    status_xxx = "#{controller.response.status / 100}XX"
    Statsd.increment("response.#{status_xxx}")
  end
end