Apply a fee via Url variable (GET) in WooCommerce - php

Question

I'm trying to carry an "add_fee" value over to review order page but it's not working.
I need to enable my check out page to wait for the url parameter "getfee".
If the getfee equals 2, then add the fee.
If it doesn't, then don't add anything.
Here's my code:
add_action( 'woocommerce_cart_calculate_fees','woocommerce_custom_surcharge' );
function woocommerce_custom_surcharge() {
global $woocommerce;
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return;
$fee = $_GET["getfee"];
if( $fee == "2") {
$percentage = 0.01;
$surcharge = ( $woocommerce->cart->cart_contents_total + $woocommerce->cart->shipping_total ) * $percentage;
$woocommerce->cart->add_fee( 'Surcharge', $surcharge, true, '' );
}
}
So far, it adds the fee in the checkout page but when it comes to reviewing the order, it doesn't appear.
I think it could be because the checkout page doesn't have that parameter but not sure.
Any help would be greatly appreciated.

Answer 1

You need to set your Url fee in a WC Session variable to avoid this problem:
// Get URL variable and set it to a WC Session variable
add_action( 'template_redirect', 'getfee_to_wc_session' );
function getfee_to_wc_session() {
if ( isset($_GET['getfee']) ) {
WC()->session->set('getfee', esc_attr($_GET['getfee']));
}
}
// Add a percentage fee
add_action( 'woocommerce_cart_calculate_fees','woocommerce_custom_surcharge' );
function woocommerce_custom_surcharge( $cart ) {
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return;
$fee = WC()->session->get('getfee'); // Get WC session variable value
if( $fee == "2") {
$percentage = 0.01;
$surcharge = ( $cart->cart_contents_total + $cart->shipping_total ) * $percentage;
$cart->add_fee( 'Surcharge', $surcharge, true, '' );
}
}
Code goes in functions.php file of your active child theme (or active theme). Tested and works.