I have an event post type. Some events are small; others are annual events and warrant their own pages. So I have a select field for events that enables the user to choose the page associated with an event.

I’ve done this before with post_meta and had no problem. But this time, because the events aren’t hierarchical, I decided to use post_parent to store the page ID. What I found is that I could set the post_parent to have a specific page value, but that I couldn’t set it to zero.

When the value is stored in post_meta, there’s no problem setting it back to zero.

Here’s the code:

<?php
/*
Title: Page Test
Description: select page for event
Post Type: event
Priority: high
Order: 20
*/

// get an array of page titles indexed by page IDs
$default_page = array( 0 => '-- none --' );
$choices = $default_page + piklist(
	get_posts( array(
		'post_type' => 'page',
		'numberposts' => -1,
		'orderby' => 'title',
		'order' => 'ASC'
	)),
	array( 'ID', 'post_title' )
);

piklist('field', array(
	'field' => 'event_page',
	'type' => 'select',
	'scope' => 'post_meta',
	'label' => 'Event Page (stored in post_meta)',
	'description' => 'If there is a special page for this event, select it here.',
	'choices' => $choices,
));

piklist('field', array(
	'field' => 'post_parent',
	'type' => 'select',
	'scope' => 'post',
	'label' => 'Event Page (stored in post_parent)',
	'description' => 'If there is a special page for this event, select it here.',
	'choices' => $choices,
));

Not surprisingly, behavior is the same for radio buttons.

HTH,
Donna