WooCommerce code - Dynamically add a surcharge to cart and checkout - wordpress

Question

I've added 2 radio buttons to my WooCommerce cart. However I want to add a surcharge when one is slected but not the other, and I want it to update the check out data that is displayed.
I know I can do this to add the surcharge all time:
add_action( 'woocommerce_cart_calculate_fees','woocommerce_custom_surcharge' );
function woocommerce_custom_surcharge() {
global $woocommerce;
$surcharge = 5.32;
$woocommerce->cart->add_fee( 'Surcharge', $surcharge, true, '' );
}
however how to I control it to add this or not based on which radio button I have selected?

Answer 1

The best way is with ajax (untested code):
<input type="radio" name"surcharge" value="5.32" class="surcharge" />
<script>
$(document).ready(function () {
$(".surcharge").click(function(){
$.ajax({
url: "where_is_your.php", // Name of PHP script
type: "POST",
data: {
action: $(this).val(), //here you get the value 5.32
}
}).done(function(data) {
alert( data.message ); //your success message if you want it
});
})
})
</script>
and your php:
add_action( 'woocommerce_cart_calculate_fees','woocommerce_custom_surcharge' );
$surcharge = $_POST['action'];
function woocommerce_custom_surcharge() {
global $woocommerce;
$woocommerce->cart->add_fee( 'Surcharge', $surcharge, true, '' );
}

Answer 2

<?php
/**
* WooCommerce Extra Feature
* --------------------------
*
* Add custom fee to cart automatically
*
*/
function woo_add_cart_fee() {
global $woocommerce;
$woocommerce->cart->add_fee( __('Custom', 'woocommerce'), 5 );
}
add_action( 'woocommerce_cart_calculate_fees', 'woo_add_cart_fee' ); ?>
You can use "woocommerce_cart_calculate_fees" to add surcharge money with an amount to your theme, and plus AJAX as above will help you out.

Answer 3

Well I solved this by creating an AJAX to handle the buttons and then in the PHP callback issuing a WC->session->set to set a session variable. Upon return, I then issue a location.reload() which refreshes the page but does not clear the cache. That way when the functions.php are loaded again, inside the surcharge function I added as a action_add, I can query the session variable to see which of the radio buttons were clicked and add the appropriate cart->add_fee.