arrays - Woocommerce 3 でのカスタム チェックアウト フィールドの検証

Question

予約 Web サイトのチェックアウト ページにカスタム入力フィールドを作成しました。入力フィールドの数は、人数に基づいています。それらをチェックアウトフォームに表示し、サニタイズして、注文管理パネルに表示することができました。入力フィールドは必須であるため、1 つ以上のフィールドが空の場合、エラー (wc_add_notice) が表示されます。wc_add_notice を取得するにはどうすればよいですか? これが私のコードです：

//* Add a new checkout field 
function ppp_filter_checkout_fields($fields){
    $fields['extra_fields'] = array(
    'participant_details' => array(
        'type' => 'participant_details',
        'required'      => true,
        'label' => __( 'Participant Details' )
        ),
    );

    return $fields;

}
add_filter( 'woocommerce_checkout_fields', 'ppp_filter_checkout_fields' );

//* Add the field to the checkout
function ppp_filter_checkout_field_group( $field, $key, $args, $value ){
    $op_cart_count = WC()->cart->get_cart_contents_count();

    $items = WC()->cart->get_cart();

    foreach($items as $item) { 
        $person = $item['booking']['_persons'][0];
    }

    if ($person > 1) {

        $html = '';

        $html .= "<h3>Deelnemers</h3>";

        for ( $i = 1; $i < $person; $i++) {
            $counter = $i + 1;

            $html .= "Deelnemer ". $counter . "<br>";

            $html .= woocommerce_form_field( "participant_details[$i][full_name]", array(
                "type" => "text",
                "return" => true,
                "value" => "",
                "required"      => true,
                "label" => __( "Naam" )
                )
            );
            $html .= woocommerce_form_field( "participant_details[$i][email_address]", array(
                "type" => "text",
                "return" => true,
                "value" => "",
                "required"      => true,
                "label" => __( "Emailadres" )
                )
            );

        }
        return $html;

    }
}
add_filter( 'woocommerce_form_field_participant_details', 'ppp_filter_checkout_field_group', 10, 4 );

//* display the extra field on the checkout form
function ppp_extra_checkout_fields(){ 

    $checkout = WC()->checkout();

    foreach ( $checkout->checkout_fields['extra_fields'] as $key => $field ) :

        woocommerce_form_field( $key, $field, $checkout->get_value( $key ) );

    endforeach;


}
add_action( 'woocommerce_checkout_after_customer_details' ,'ppp_extra_checkout_fields' );

//* Sanitize our custom field
function ppp_custom_process_checkout_field_participant_details( $posted ){

    $clean = array();

    foreach( $posted as $participant ){
        $details = ppp_custom_checkout_clean_participant_details( $participant );

        if( ! empty( $details ) ){
            $clean[] = $details;
        }
    }

    return $clean;
}
add_filter( 'woocommerce_process_checkout_participant_details_field', 'ppp_custom_process_checkout_field_participant_details' );

//*
function ppp_custom_checkout_clean_participant_details( $participant = array() ){
    $details = array();
    if( isset( $participant["full_name"] ) ){
        $details['full_name'] = sanitize_text_field( $participant["full_name"] );
    }
    if( isset( $participant["email_address"] ) ){
        $details['email_address'] = sanitize_text_field( $participant["email_address"] );
    }
    return $details;
}

//* Update_post_meta
function ppp_custom_checkout_field_update_order_meta( $order_id, $posted ){

    if( ! empty( $posted["participant_details"] ) ){
        update_post_meta( $order_id, "_participant_details", $posted["participant_details"] );
    } else {
        delete_post_meta( $order_id, "_participant_details" );
    }

}
add_action( 'woocommerce_checkout_update_order_meta', 'ppp_custom_checkout_field_update_order_meta', 10, 2 );

//* Display the extra data in the order admin panel
function ppp_display_order_data_in_admin( $order ){  

    $participant_details = get_post_meta( $order->id, "_participant_details", true ); 

    if( ! empty( $participant_details ) ) { 

        $participant_defaults = array(
                "full_name" => "",
                "email_address" => ""
            );

    ?>
    <div class="participant_data">
        <h4><?php _e( "Deelnemers Lijst", "prespersadprodukties" ); ?></h4>
        <?php 
            $i = 1;

            foreach( $participant_details as $participant ){

                $participant = wp_parse_args( $participant, $participant_defaults );

                echo "<p><strong>" . sprintf( __( "Deelnemer %s", "prespersadprodukties" ), $i+1  ) . "</strong>" . "<br/>";
                echo __( "Naam", "prespersadprodukties" ) . ' : ' . $participant["full_name"] . "<br/>";
                echo __( "Emailadres", "prespersadprodukties" ) . ' : ' . $participant["email_address"] . "<br/>";
                echo "</p>";

                $i++;

            }

         ?>
    </div>
<?php }
}
add_action( 'woocommerce_admin_order_data_after_order_details', 'ppp_display_order_data_in_admin' );