How to dynamically populate a page reference field in ProcessWire

I recently had a requirement where I wanted to reuse a ProcessWire Page Reference field across pages and templates. I wanted the field in each case to list its children. Here's how I accomplished it (add this hook to your admin.php.

					
wire()->addHookAfter('InputfieldPage::getSelectablePages', function($event) {

    $page = $event->arguments('page');

    // Don't run on admin as it causes an error when you try to access template override settings
    if ($page->template->name != 'admin' && $event->object->hasField == 'dynamicPageReference') {

        $event->return = $page->children('template=dynamic-page-reference-option'); // Do any $page work you like here

    }

});