[kh99]

Instead of a static html widget, try creating a php direct execution widget and use code like this:

$templater = vB_Template::create('ajax_chat_widget');
$output = $templater->render();

Also, those instructions you linked to show another plugin using hook global_bootstrap_init_start that calculates the number chatting, so you'd need to add another preRegister call there as well.

When configuring the php direct execution widget, there's a field for cache time. If you set it to 0 it will execute every time someone accesses a page that shows the widget, but if you set it to 1 (the minimum allowed), then the widget will only update once per minute. You can choose which one works for you. Setting it to 0 probably isn't a problem since you aren't doing much in your widget code, and the database queries in the plugin are being done each time anyway.