How to add conditional shipping cost to ubercart order?

Question

I am building an e-commerce site. When a shippable item is added to the cart I have to add some fixed shipping cost to the order which I am able to do with flat rate. But I have to add an option "Residential Delivery Fee" while showing shipping cost on checkout page. If user select this option during checkout then I have to add another shipping cost to the order.

I am unable to figure out that how to add this conditional shipping cost.

Answer 1

Here the idea,

1. Using hook_checkout_pane() include your option "Residential Delivery Fee" as checkbox
2. Then while saving order check if user selected this option. Use hook_order
3. If user chose this option, you can add your shipping charge as line item with the function uc_order_line_item_add().

foreg:

function hook_order(){
switch ($op) {
.....................
case 'save':
if($arg1->residential){
//if the checkbox was selected, we add the line item to the order. the following function  will add 100 to order total as shipping charge
uc_order_line_item_add
    (
      $arg1->order_id, 
      'shipping',
      t('Residential Delivery Fee'), 
      100, 
      NULL,
      array () 
    );

 }
}

I successfully implemented this idea for one of my client site