Error while inserting $field_id in rwmb_after_save_post

Hi Ben,

Can you please share the code that creates the group field and subfields on your site?
pieces_jointes_et_dates and date_fichier

You can also refer to this topic to know how to get group field and update subfield value in a group
https://support.metabox.io/topic/update_post_meta-for-cloneable-group-fields/#post-36899

Hi Ben,

So do you want to sort the cloneable group based on the subfield value (date)? Meta Box does not support a field type bs_date so I'm not sure what exactly the field value is but the main goal is, you need to update the group value outside the loop. For example:

add_action( 'rwmb_pieces_jointes_et_dates_after_save_post', function( $object_id ) {
    $group_values = rwmb_meta( 'pieces_jointes_et_dates', '', $object_id );
    if ( ! empty( $group_values ) ) {
        foreach ( $group_values as $group_key => $group_value ) {
            $dates_to_sort = isset( $group_value['date_fichier'] ) ? $group_value['date_fichier'] : '';

            // do something here to update the subfield value for each clone group
            $group_values[$group_key]['date_fichier'] = '9/2/2022';
        }
    }
    //update the whole group value
    update_post_meta( $object_id, 'pieces_jointes_et_dates', $group_values );
} );

hi ben06,

you can use the following code for sorting your group by date

add_action( 'rwmb_pieces_jointes_et_dates_after_save_post', function($object_id){

    $pj = $_POST['pieces_jointes_et_dates'];
    //sorting by date with usort 
    usort($pj, function($a, $b) {
        //convert date_fichier DD/MM/YYYY with datetime to get a timestamp that you can sort
        $a_date = DateTime::createFromFormat('d/m/Y', $a['date_fichier']);
        $b_date = DateTime::createFromFormat('d/m/Y', $b['date_fichier']);
        return $a_date->getTimestamp() - $b_date->getTimestamp();
    });

    //Then update the whole group value
    update_post_meta($object_id,'pieces_jointes_et_dates', $pj );
} );

Have a nice day 🙂