WordPress update_post_meta () не работает должным образом

Question

У меня есть save_post ловушка действия в WordPrss.

<code>function save_meta_function ( ) {
    global $post;   
    $post_id        =   $post->ID;
    $meta_values    =   get_post_meta( $post_id );      
    // echo '<pre>';
    // print_r($meta_values);
    // echo '

';foreach ($ meta_values ​​как $ key => $ value) {// print_r ($ key);// print_r ($ значение [0]);// $ newValue = $ value [0];update_post_meta ($ post_id, $ key, $ value [0]);}} add_action ('save_post', 'save_meta_function');

Вот эта прокомментированная строка:

<code>// echo '<pre>';
// print_r($meta_values);
// echo '

';

напечатает это:

<pre>Array
(
    [people_0] => Array
        (
            [0] => 2
        )

    [people_1] => Array
        (
            [0] => two@gmail.com
        )

    [people_2] => Array
        (
            [0] => Author Two
        )

    [people_3] => Array
        (
            [0] => Author Aff 2
        )

    [people_4] => Array
        (
            [0] => #2- Article 2 Title
        )

    [people_5] => Array
        (
            [0] => Article 2 URL
        )

    [people_6] => Array
        (
            [0] => Article 2 Journal
        )

    [people_7] => Array
        (
            [0] => Article 2 Abstract
        )

    [people_8] => Array
        (
            [0] => Co Author 2
        )

    [people_9] => Array
        (
            [0] => Co Author Aff 2
        )

    [people_10] => Array
        (
            [0] => co-author-2@gmail.com
        )

    [people_11] => Array
        (
            [0] => Article 2 Title
        )

    [people_12] => Array
        (
            [0] => Article 2 URL
        )

    [people_13] => Array
        (
            [0] => Article 2 Journal
        )

    [people_14] => Array
        (
            [0] => Article 2 Abstract
        )

    [people_15] => Array
        (
            [0] => Co Author 2
        )

    [people_16] => Array
        (
            [0] => Co Author Aff 2
        )

    [people_17] => Array
        (
            [0] => co-author-2@gmail.com
        )

    [_edit_lock] => Array
        (
            [0] => 1562141363:1
        )

    [_edit_last] => Array
        (
            [0] => 1
        )

)

Теперь, когда я отредактировал или добавил новые данные, тогда по какой-то причине update_post_meta() метод не обновил метаданные поста :( Можете ли вы сказатьмне почему?