Expresso Store: checkout and order custom field w/ amout value - how to calculate total

Question

I have added an order custom field to the checkout process named "Would you like this order gift wrapped?" and there is one choice (check box) which is passing value, which is marking that order as a gift, but now store owner has decided to have added some $ amount to the total when that options is checked.

My code looks like:

          <td>Would you like this order gift wrapped?</td>
            <td colspan="2"><input type="checkbox" value="yes" name="order_custom1" /> Yes</td>
            <td style="text-align:right"><input type="hidden" value="5.00" name="order_custom2" /> $5.00</td>
        </tr>     

Now how I can update total with value of order_custom2 when order_custom1 is not empty on Update Total (or auto update total w/ jQuery on check box checked event)?

Thanks

Answer 1

You will need to use a product instead of a custom order field.

In Store 2, the checkout tag and add to cart tag both submit to the same URL, so you can use this to add optional products to the cart during checkout.

To do this, the high level overview is that you simply submit a hidden field with the entry_id along with the standard update cart fields.

For example:

<input type="hidden" name="items[0][entry_id]" value="123" />
<!-- hidden input so that unselecting the checkbox submits 0 quantity -->
<input type="hidden" name="items[0][update_qty]" value="0" />
<input type="checkbox" name="items[0][update_qty]" value="1" selected /> Gift wrapping?

update_qty is exactly like item_qty, except that it overwrites any existing quantity in the cart rather than adding to it.

The only difference between this and the regular add to cart form is that you have to wrap the inputs with items[num][]. This allows multiple products to be added/updated at once.

This is similar to how the product form tag works (they all submit to the same endpoint).