In Ruby on Rails, how can you use vanity URLs and also redirect to 404s?

Question

At the end of my routes.rb, I have a wildcard match for vanity urls. However, I can't figure out how to redirect unknown usernames to a 404. How can you do this?

~ in routes.rb ~

# Vanity URLs
match ':username', :to => "users#show"

~ in the users controller ~

@user = User.find_by_username(params[:username])
if @user.nil?
  render :status => 404
else
  ...
end

Answer 1

What you have will still render the default template but, with a 404 response code.

Try this to render the default 404 page instead:

render :file => "#{Rails.root}/public/404.html", :layout => false, :status => 404