In order to render a system widget, you need to invoke hook_html_panel_make_widgets
That means, you figure out which module creates the widget you want (e.g. mailing_list) and replace the word "hook" with the module name. The function takes one argument: $delta. It is always 0 unless the module generates multiple widgets*
This will give you a nested array containing your widget. You will need to access [hook][$delta]['body'] to get the contents of the widget
So if hook is mailing list:
<?php
$widgets = mailing_list_html_panel_make_widgets(0);
print $widgets['mailing_list'][0]['body'];
?>
The options for hook are currently:
- catalog
- discography
- member_display
- merch_display
- tour_display
- blog_display
- news_display
- media_display
- audio_display
- fan_club
- file_host
- mailing_list
* media_display is the only one that has multiple widgets right now. Passing in 0 will return the photo widget. 1 will return the video widget.