How do you issue a 404 response from a rails controller action?

Question

What's the preferred way to issue a 404 response from a rails controller action?

Answer 1

This seems good...

render :file => "#{RAILS_ROOT}/public/404.html",  :status => 404

Answer 2

Reference:

render :file => '/path/to/some/filenotfound.rhtml', 
                status => 404, :layout => true

Answer 3

In the ApplicationController define a method like:

def render_404
  render :file => "#{RAILS_ROOT}/public/404.html",  :status => 404
end