// Disable Flat Rate if Free Shipping is available
add_filter( 'woocommerce_package_rates', 'hide_flat_rate_when_free_is_available', 100, 2 );
function hide_flat_rate_when_free_is_available( $rates, $package ) {
// Debug: write to WooCommerce log
wc_get_logger()->info( 'Package rates: ' . print_r( array_keys( $rates ), true ), array( 'source' => 'shipping-debug' ) );
$free_shipping_exists = false;
// First check if free shipping is available
foreach ( $rates as $rate_id => $rate ) {
if ( strpos( $rate_id, 'free_shipping' ) === 0 ) {
$free_shipping_exists = true;
break;
}
}
// If free shipping exists, remove all flat rates
if ( $free_shipping_exists ) {
foreach ( $rates as $rate_id => $rate ) {
if ( strpos( $rate_id, 'flat_rate' ) === 0 ) {
unset( $rates[ $rate_id ] );
}
}
}
return $rates;
}