WooCommerce Fragment Update total items / subtotal / total - ajax

Question

I am usign Ajax to add items to my cart, and trying to use the below code to update the WooCommerce fragments so that the item count, subtotal and total stay in sync (without page refresh). However, The below is not working, apart from the contents count, but even this is very intermittent.
Am I missing something?
function ajaxify_fragments( $fragments ) {
// Update cart count fragment
$fragments['.cart-items-total td'] = WC()->cart->get_cart_contents_count();
// Update cart subtotal fragment
$fragments['.cart-total td'] = WC()->cart->get_cart_subtotal();
// Update cart total fragment
$fragments['.cart-total td'] = WC()->cart->get_cart_total();
return $fragments;
}
add_filter( 'woocommerce_add_to_cart_fragments', 'ajaxify_fragments', 10, 1 );

Answer 1

After some further research, I have got this to work by separating out each fragment update into its own function. Also, using ob_start() and ob_get_clean():
function ajaxify_cart_count_fragments( $fragments ) {
// Turn on output buffering
ob_start();
// Content
echo '<td data-title="Items">' . WC()->cart->get_cart_contents_count() . '</td>';
// Update fragment with new content
$fragments['.cart-items-total td'] = ob_get_clean();
return $fragments;
}
add_filter( 'woocommerce_add_to_cart_fragments', 'ajaxify_cart_count_fragments', 10, 1 );
function ajaxify_subtotal_fragments( $fragments ) {
// Content
echo '<td data-title="Subtotal">' . WC()->cart->get_cart_subtotal() . '</td>';
// Update fragment with new content
$fragments['.cart-total td'] = WC()->cart->get_cart_subtotal();
return $fragments;
}
add_filter( 'woocommerce_add_to_cart_fragments', 'ajaxify_subtotal_fragments', 10, 1 );