Custom validation of WooCommerce checkout fields

Question

I would like add my own regular expression for validating the phone number. In my class-wc-validation.php I have changed the regular expression to my requiremen

Answer 1

Was facing the same issue and followed what others had said here, but Woocommerce only sets the errors on validation after woocommerce_checkout_process hook.

But, in the latest Woocommerce 3.0 (not sure if this is in the 2.x version), we can use the woocommerce_after_checkout_validation hook and then look into the $data param if you are using the standard checkout fields or use $_POST if you have custom fields that aren't added in the standard Woocommerce way. An example of the code is:

public function validate($data,$errors) { 
    // Do your data processing here and in case of an 
    // error add it to the errors array like:
        $errors->add( 'validation', __( 'Please input that correctly.' ));
}
add_action('woocommerce_after_checkout_validation', 'validate',10,2);

Hope that helps!