Force 'www' in Rails3 hosted on Heroku without .htaccess

I was wondering if there was a Rack alternative to forcing the 'www' in the URL since Heroku doesn't 开发者_如何学运维use .htaccess files.

Maybe even a nice way to do it in routes?

Thanks

---

In your ApplicationController, you can simply create a before filter:

before_filter :force_www!

protected

def force_www!
  if Rails.env.production? and request.host[0..3] != "www."
    redirect_to "#{request.protocol}www.#{request.host_with_port}#{request.fullpath}", :status => 301
  end
end

Or to go the other direction and remove www:

before_filter :remove_www!

protected

def remove_www!
  if Rails.env.production? and request.host[0..3] == "www."
    redirect_to "#{request.protocol}#{request.host_with_port[4..-1]}#{request.fullpath}", :status => 301
  end
end

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A quick Google search reveals this Rack middleware, which appears to do exactly what you want.