Using autofocus and text_field form helpers in Ruby

Question

How do I include the 'autofocus' attribute on an HTML5 form using the text_field form helper in ruby?

e.g. <%= f.text_field :email %> Where does autofocus go?

Thanks

Answer 1

f.text_field :email, :autofocus=>"true"

though, not sure if the value is "true" or "autofocus"