WooCommerce Custom Text Field On Registration Form

/**
 * Snippet Name:	WooCommerce Custom Text Field On Registration Form
 * Snippet Author:	ecommercehints.com
 */

// Create the new license plate text field
add_action( 'woocommerce_register_form', 'ecommercehints_register_text_form_field' );
function ecommercehints_register_text_form_field() {
	woocommerce_form_field(
		'license_plate',
		array(
			'type'        => 'text',
			'required'    => true, // If true show an asterisk (*)
			'label'       => 'Vehicle License Plate',
			'description' => 'Personalised plates are permitted',
		),
		( isset($_POST['license_plate']) ? $_POST['license_plate'] : '' )
	);
}

// Show an error if license plate text field is not filled out when registering
add_action( 'woocommerce_register_post', 'ecommercehints_validate_license_plate', 10, 3 );
function ecommercehints_validate_license_plate( $username, $email, $errors ) {
	if ( empty( $_POST['license_plate'] ) ) {
		$errors->add( 'license_plate_error', 'We can\'t send you a quote without your license plate' );
	}
}

// Save the license plate text field as User Meta
add_action( 'woocommerce_created_customer', 'ecommercehints_save_license_plate_field' );
function ecommercehints_save_license_plate_field( $customer_id ){
	if ( isset( $_POST['license_plate'] ) ) {
		update_user_meta( $customer_id, 'license_plate', wc_clean( $_POST['license_plate'] ) );
	}
}

// Show license plate text field in the User Editor
add_action('show_user_profile', 'custom_user_profile_fields');
add_action('edit_user_profile', 'custom_user_profile_fields');

function custom_user_profile_fields( $user ) { ?>
<h2>Custom user meta fields</h2>
    <table class="form-table">
        <tr>
            <th>
                <label for="license_plate"><?php _e( 'license_plate' ); ?></label>
            </th>
            <td>
                <input type="text" name="license_plate" id="license_plate" value="<?php echo esc_attr( get_the_author_meta( 'license_plate', $user->ID ) ); ?>" class="regular-text" />
            </td>
        </tr>
    </table>
<?php
}

// Save new license plate text field if edited by admin
add_action( 'personal_options_update', 'update_extra_profile_fields' );
add_action( 'edit_user_profile_update', 'update_extra_profile_fields' );
function update_extra_profile_fields( $user_id ) {
    if ( current_user_can( 'edit_user', $user_id ) )
        update_user_meta( $user_id, 'license_plate', $_POST['license_plate'] );
}