How/where is the global variable $wp_registered_widgets filled?

Question

I have a problem of widgets not showing up, trying to investigate why $wp_registered_widgets is empty.

Can somebody tell me where it gets filled from the database? How can I find out why the default widgets are not set.

Answer 1

As you can see here, $wp_registered_widgets is defined in wp-includes/widgets.php (as expected). You should be able to debug it by doing something like this:

function yoast_print_active_widgets() {
    global $wp_registered_widgets;    
    echo '<pre>'.print_r( $wp_registered_widgets, 1 ).'</pre>';
}
add_action('init','yoast_print_active_widgets');

Then you could loop through the different stages, from init, to send_headers to wp_head and see where stuff goes wrong...