method

expires_in

v6.0.0 - Show latest stable - Class: ActionController::ConditionalGet

expires_in(seconds, options = {})

public

Sets an HTTP 1.1 Cache-Control header. Defaults to issuing a private instruction, so that intermediate caches must not cache the response.

expires_in 20.minutes
expires_in 3.hours, public: true
expires_in 3.hours, public: true, must_revalidate: true

This method will overwrite an existing Cache-Control header. See www.w3.org/Protocols/rfc2616/rfc2616-sec14.html for more possibilities.

HTTP Cache-Control Extensions for Stale Content. See tools.ietf.org/html/rfc5861 It helps to cache an asset and serve it while is being revalidated and/or returning with an error.

expires_in 3.hours, public: true, stale_while_revalidate: 60.seconds
expires_in 3.hours, public: true, stale_while_revalidate: 60.seconds, stale_if_error: 5.minutes

The method will also ensure an HTTP Date header for client compatibility.

# File actionpack/lib/action_controller/metal/conditional_get.rb, line 238
    def expires_in(seconds, options = {})
      response.cache_control.merge!(
        max_age: seconds,
        public: options.delete(:public),
        must_revalidate: options.delete(:must_revalidate),
        stale_while_revalidate: options.delete(:stale_while_revalidate),
        stale_if_error: options.delete(:stale_if_error),
      )
      options.delete(:private)

      response.cache_control[:extras] = options.map { |k, v| "#{k}=#{v}" }
      response.date = Time.now unless response.date?
    end

1Note

This doesn't write files

reconbot · May 8, 2015

This doesn't write files, at least not anymore. Since at least rails 4 Rack::Cache isn't included by default. In any case this method only ever set headers on the response.

expires_in

1Note

This doesn't write files

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