Change WooCommerce shipping method full label based on product shipping class

Question

I want to add a custom message on the cart page in WooCommerce. The message should appear depending on the shipping class assigned to the product, in the woocommerce_cart_shipping_method_full_label hook.

I already have code that does it, but it doesn't work when I assign it to that hook, it only works if I assign it to the woocommerce_before_calculate_totals hook.

When I want to add it to the woocommerce_cart_shipping_method_full_label hook, I get the message:

Fatal error: Uncaught Error: Call to a member function get_cart()

Could someone advise me on what I'm doing wrong? I am using the storefront template with a child theme.

Based on Cart Message for a Specific Shipping Class in WooCommerce answer code, this is the code I'm using in the functions.php:

add_action( 'woocommerce_cart_shipping_method_full_label', 'cart_items_shipping_class_message', 20, 1 );
function cart_items_shipping_class_message( $cart ){
    if ( ! is_cart() || ( is_admin() && ! defined( 'DOING_AJAX' ) ) )
        return;

    if ( did_action( 'woocommerce_cart_shipping_method_full_label' ) >= 2 )
        return;

    $shipping_class_id = '28'; // Your shipping class Id

    // Loop through cart items
    foreach( $cart->get_cart() as $cart_item ) {
        // Check cart items for specific shipping class, displaying a notice
        if( $cart_item['data']->get_shipping_class_id() == $shipping_class_id ){
            wc_clear_notices();

            wc_add_notice( sprintf( __('My custom message.', 'woocommerce'), '' . __("Pallet Shipping", "woocommerce") . ''), 'notice' );

            break;
        }
    }
}

Answer 1

Mapping code written for one hook to another hook sometimes takes some tweaking, depending on the original hook and the newly mapped hook:

• For example, $cart is not passed to the callback function, and hence the error message you get
• wc_clear_notices() and wc_add_notice() are not applicable, as the hook you wish to use is to change the $label
• if ( did_action( 'woocommerce_cart_shipping_method_full_label' ) >= 2 ) does not exist

So you get:

function filter_woocommerce_cart_shipping_method_full_label( $label, $method ) {
    // Your shipping class Id
    $shipping_class_id = 28;

    // WC Cart
    if ( WC()->cart ) {
        // Get cart
        $cart = WC()->cart;

        // Loop through cart items
        foreach ( $cart->get_cart() as $cart_item ) {
            // Check cart items for specific shipping class
            if ( $cart_item['data']->get_shipping_class_id() == $shipping_class_id ) {
                $label = __( 'My custom message', 'woocommerce' ); 
                break;
            }
        }
    }

    return $label; 
}
add_filter( 'woocommerce_cart_shipping_method_full_label', 'filter_woocommerce_cart_shipping_method_full_label', 10, 2 );