Changing méta box system

That’s a good question! Thanks for asking!

Basically migrating to Meta Box isn’t hard. If you save a value in a single row in the post meta table, then you just need to register a field with id = meta key, that’s all.

To understand how meta value is saved in Meta Box, please read this docs:

https://metabox.io/docs/how-post-meta-is-saved-in-the-database/

Best regards

Thanks for reply !
So if I understand, I must refer to the old field’s id to create the meta box.

Like this :

// 1st meta box
    $meta_boxes[] = array(
        'id'         => 'personal',
        ...
        'fields' => array(
            array(
                'name'  => __( 'Full name', 'textdomain' ),
                'id'    => $prefix . 'id_of_my_old_field',
                'type'  => 'text'
            ),
        )
    );

That’s right. Just a note: $prefix . ‘id_of_my_old_field’ = ‘your old field id’.