gistfile1.txt

# add to site_extension.rb
Checkout.class_eval do
    state_machine do
      before_transition :to => 'confirm' do |checkout, transition|
        !checkout.payments.first.nil? && !checkout.payments.first.source_id.nil? 
      end
    end
 end         

# override update method in CheckoutsController
CheckoutsController.class_eval do
  def update
    load_object

    # call the edit hooks for the current step in case we experience validation failure and need to edit again
    edit_hooks
    @checkout.enable_validation_group(@checkout.state.to_sym)
    @prev_state = @checkout.state

    before :update

    begin
      if @checkout.update_attributes object_params
        update_hooks
        @checkout.order.update_totals!
        after :update
        next_step
        if @checkout.completed_at
          return complete_checkout
        end
      else
        after :update_fails
        set_flash :update_fails
      end
    rescue Spree::GatewayError => ge
      logger.debug("#{ge}:\n#{ge.backtrace.join("\n")}")
      flash.now[:error] = t("unable_to_authorize_credit_card") + ": #{ge.message}"
    rescue
      logger.debug("tried to move beyond payment checkout without entering payment info")
    end

    render 'edit'
  end
  
end