Sets the etag and/or last_modified on the response and checks it against the client request. If the request doesn’t match the options provided, the request is considered stale and should be generated from scratch. Otherwise, it’s fresh and we don’t need to generate anything and a reply of "304 Not Modified" is sent.
def show @article = Article.find(params[:id]) if stale?(:etag => @article, :last_modified => @article.created_at.utc) @statistics = @article.really_expensive_call respond_to do |format| # all the supported formats end end end
# File actionpack/lib/action_controller/base.rb, line 1112 def stale?(options) fresh_when(options) !request.fresh?(response) end