Position right sidebar metabox right below the publish metabox?

Question

I have a custom post meta box that I want to put in the right sidebar. When I set the priority to high it appears in the number 1 spot in sidebar above everything. If I set to core it appear at the bottom of right sidebar.

My desired position is in the number 2 spot in the right sidebar. Right below the publish metabox.

Is this possibble?

Answer 1

Still if its something like client requirement then below is somewhat hack sort of solution. Add this code to your add_meta_box() function. For the sake of understanding, below I have provided complete function but you will need to use selective code :-) Do let me know how it goes.

function myplugin_add_meta_box() {

    $screens = array( 'post', 'page' );

    foreach ( $screens as $screen ) {

        add_meta_box(
            'testdiv',
            __( 'My Post Section Title', 'myplugin_textdomain' ),
            'myplugin_meta_box_callback',
            $screen,
            'side'
        );
    }
    /* Get the user details to find user id for whom this order should be shown. Ideally, I believe it will be admin user. Make sure you change the email id*/
    $user = get_user_by( 'email', 'xyz@example.com' ); 
    $order = get_user_option("meta-box-order_post", $user->ID);

    $current_order = array(); 
    $current_order = explode(",",$order['side']);

    for($i=0 ; $i <= count ($current_order) ; $i++){
        $temp = $current_order[$i];
        if ( $current_order[$i] == 'testdiv' && $i != 1) {
            $current_order[$i] = $current_order[1];         
            $current_order[1] = $temp;          
        }
    }

    $order['side'] = implode(",",$current_order);

    update_user_option($user->ID, "meta-box-order_page", $order, true);
    update_user_option($user->ID, "meta-box-order_post", $order, true);

}
add_action( 'add_meta_boxes', 'myplugin_add_meta_box', 2 );

Answer 2

After some experimentation, I have come up with this method which may be a tad more robust:

add_action('add_meta_boxes', function () {
    $screens = array('post', 'page');

    foreach ($screens as $screen) {
        add_meta_box("metabox_name", "Meta Box Title", "my_metabox_callback", $screen, "side", "high");

        // Force the box to display below the 'Publish' metabox
        $user = wp_get_current_user(); 
        $order = get_user_option("meta-box-order_".$screen, $user->ID);

        if(strpos($order['side'], "metabox_name") !== false) {
            $order = str_replace('metabox_name,', '', $order['side']);
        }

        if(strpos($order['side'], "submitdiv") === false) {
            $order['side'] = 'submitdiv,' . $order['side'];
        }

        if(substr($order['side'], -1) == ",") {
            $order['side'] = substr($order['side'], 0, -1);
        }

        $current_order = array(); 
        $current_order = explode(",", $order['side']);

        // Add this metabox to the order array
        $key = array_search('submitdiv', $current_order, true);

        if($key !== false) {
            $new_order = array_merge(
                array_slice($current_order, 0, $key+1),
                array("metabox_name")
            );

            if(count($current_order) > $key) {
                $new_order = array_merge(
                    $new_order,
                    array_slice($current_order, $key+1)
                );
            }

            $order['side'] = implode(",", $new_order);

            update_user_option($user->ID, "meta-box-order_".$screen, $order, true);
        }
    }
});

This doesn't feel very elegant to me, but it does work in a variety of situations where the earlier answer fails (e.g. new users).