method

expires_in

expires_in(seconds, options = {})
public

Sets a 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 http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html for more possibilities.

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

1Note

This doesn't write files

reconbot ยท 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.