Ist eine Hausnummer vorhanden?

woocommerce_checkout_process.php

add_action('woocommerce_checkout_process', 'custom_validation_process');

function custom_validation_process() {
	global $woocommerce;
	if (isset($_POST['billing_address_1']) and $_POST['billing_address_1'] != '') {
		if (!preg_match('/([0-9]+)/Uis', $_POST['billing_address_1'])) {
			if (function_exists('wc_add_notice'))
				wc_add_notice( __('Hausnummer fehlt!'), 'error' );
			else
				$woocommerce->add_error( __('Hausnummer fehlt!') );
		}
	}
	if (isset($_POST['ship_to_different_address'])) {
		if (isset($_POST['shipping_address_1']) and $_POST['shipping_address_1'] != '') {
			if (!preg_match('/([0-9]+)/Uis', $_POST['shipping_address_1'])) {
				if (function_exists('wc_add_notice'))
					wc_add_notice( __('Hausnummer fehlt!'), 'error' );
				else
					$woocommerce->add_error( __('Hausnummer fehlt!') );
			}
		}
	}
}