WordPress: Sort user sites by name in the Admin Bar

admin-bar-sort-sites.php

<?php
/**
 * Sorts user sites by name in the Admin Bar.
 *
 * @param object $wp_admin_bar Admin Bar instance.
 */
function goblindegook_admin_bar_sort_sites( &$wp_admin_bar ) {

	if ( ! is_user_logged_in() ) {
		return;
	}

	usort( $wp_admin_bar->user->blogs, function ( $a, $b ) {
		return strcmp( $a->blogname, $b->blogname );
	} );
}

add_action( 'admin_bar_menu', 'goblindegook_admin_bar_sort_sites' );