Which action hook to update custom field at network/site-info.php in multisite on update site info

Question

I am currently using code to add a custom field to the site-info.php & site-new.php in the network admin management to add a custom option to the database, this does work when I create a new subsite, it gets set in the database and retrieves the value inside the input value.

But when I try to update the value of this custom option, while updating site-info, this doesn't even reach the function, most likely because I'm using the (wrong) hook wpmu_new_blog, because I am updating I've tried using wpmu_blog_updated, wpmu_edit_blog, wpmu_update_blog, but I just can't get it to work.

Any help would be appreciated.

My code is as follows:

//Add custom field Site-options Network-admin
add_action('admin_footer', 'user16975_custom_options');
function user16975_custom_options(){
    global $pagenow;
    if( 'site-info.php' == $pagenow OR 'site-new.php' == $pagenow ) {

        if(ctype_digit($_GET['id']))
            $custom_limit_site_id = $_GET['id']; 
        else
            $custom_limit_site_id ='';

        ?><table><tr id="user16975_custom_options">
            <th scope="row">Maximaal aantal gebruikers</th>
            <td><input type="text" name="blog[custom_limit_amount]" value="<?=get_blog_option( $custom_limit_site_id, 'custom_limit_amount', '10' );?>"/></td>
        </tr></table>
        <script>jQuery(function($){
            $('.form-table tbody').append($('#user16975_custom_options'));
        });</script><?php
    }
}

function add_new_blog_field($blog_id, $user_id, $domain, $path, $site_id, $meta) {
    switch_to_blog($blog_id);
    $new_field_value = '10';

    if ( !empty($_POST['blog']['custom_limit_amount']) )
        $new_field_value = $_POST['blog']['custom_limit_amount'];

    update_option( 'custom_limit_amount', $new_field_value);
    restore_current_blog();
}
add_action( 'wpmu_new_blog', 'add_new_blog_field' );

function edit_blog_field($blog_id) {
    if ( !empty($_POST['blog']['custom_limit_amount']) )
        $new_field_value = $_POST['blog']['custom_limit_amount'];

    update_blog_option ($blog_id, 'custom_limit_amount', $new_field_value);
    restore_current_blog();
}
add_action( 'wpmu_blog_updated', 'edit_blog_field' );

Answer 1

After some more research I found a solution, turned out that I had to use admin_init..

function pg_save_custom_site_options(){
    global $pagenow;
    if( 'site-info.php' == $pagenow && isset($_REQUEST['action']) && 'update-site' == $_REQUEST['action'] ) 
    {
        if ( isset( $_POST['blog']['custom_limit_amount'] ) ) 
        {
            $new_field_value = intval( $_POST['blog']['custom_limit_amount'] );
            if( is_int($new_field_value) ){
                update_blog_option( $_POST['id'], 'custom_limit_amount', $new_field_value );
            }
        }
    }
}
add_action('admin_init', 'pg_save_custom_site_options');