module Padrino::Helpers::FormHelpers

def form_for(object, url, settings={}, &block)

form_for @user, '/register', :id => 'register' do |f| ... end
form_for :user, '/register' do |f| ... end
Constructs a form for object using given or default form_builder 
def form_for(object, url, settings={}, &block)
  builder_class = configured_form_builder_class(settings[:builder])
  form_html = capture_html(builder_class.new(self, object), &block)
  form_tag(url, settings) { form_html }
end