gistfile1.aw

<?php
public function event_content_relationship_meta_box( $post ) {
wp_nonce_field( 'tc_event_relationship_noncename', 'tc_event_relationship_nonce' );

$current_term = array();
if ( $current_relationship = get_post_meta( $post->ID, '_tc_event_relationship', true ) ) {
	if ( $event_type = get_the_terms( (int) $current_relationship, 'tc_event_type_taxonomy' ) )
		$current_term = get_term( $event_type[0]->term_id, 'tc_event_type_taxonomy' );
}

$eventtypes = get_terms( array( 'tc_event_type_taxonomy' ) );
?>

<script>
	//Event Type autocomplete
	var tc_eventTypes = [
	<?php
		foreach ( $eventtypes as $type ) : ?>
			{ label: "<?php echo esc_js( $type->name ); ?>", value: "<?php echo esc_js( $type->name ); ?>", termid: "<?php echo esc_js( $type->term_id ); ?>" },
		<?php endforeach; ?>
	];

	jQuery(document).ready(function() {
		//Add autocomplete with functionon select to grab the appropriate event posts.
		jQuery( '#event-type-name' ).autocomplete({
			source: tc_eventTypes,
			html: true,
			select: function(event, ui) {
				jQuery('#event-type-name').val(ui.item.label);

				jQuery('#tc-event-relationship-container').html('<img src="<?php echo admin_url( '/images/loading.gif' ); ?>" alt="Loading..." />');

				jQuery.post( ajaxurl, {
					action: 'tc_load_events_of_type',
					event_type_term_id: ui.item.termid,

				}, function(response){
					if( '' == response ) {
						jQuery('#tc-event-relationship-container').html('<p>There are no recently ended or close approaching events of this type.</p>');
					} else {
						jQuery('#tc-event-relationship-container').html(response);
					}
				});
				return false;
			}
		});
	});
</script>
<p>
	<label for="event-type-name" class="screen-reader-text">Event Type:</label>
	<input type="text" placeholder="Event Type" class="widefat" id="event-type-name" name="event-type-name" value="<?php echo ( empty( $current_term ) ) ? '' : $current_term->name; ?>" />
	<span class="description">Type the event type.</span>
</p>
<div id="tc-event-relationship-container">
	<?php
		if ( ! empty( $current_term ) ) {
		?>
			<select id="_tc_event_relationship" name="_tc_event_relationship" class="widefat">
				<option></option>
			<?php
				$events = get_posts(
					array(
						'post_type' => 'tc_events',
						'orderby' => 'meta_value_num',
						'order' => 'DESC',
						'meta_key' => '_tc_event_start',
						'posts_per_page' => 100,
						'meta_query' => array(
							array(
								'key' => '_tc_event_start',
								'value' => get_date_from_gmt( date( 'Y-m-d H:i:s' ), 'U' ) + 5184000, //let's say event start is up to 2 months in the future
								'compare' => '<=',
								'type' => 'NUMERIC',
							),
							array(
								'key' => '_tc_event_end',
								'value' => get_date_from_gmt( date( 'Y-m-d H:i:s' ), 'U' ) - 31104000, //and lets say all events that ended 12 months prior
								'compare' => '>=',
								'type' => 'NUMERIC',
							),
						),
						'tax_query' => array(
							array(
								'taxonomy' => 'tc_event_type_taxonomy',
								'field' => 'id',
								'terms' => $current_term->term_id,
							),
						),
					)
				);

				if ( $events ) {
					foreach ( $events as $event ) {
					?>
						<option id="event-<?php echo $event->ID; ?>" value="<?php echo $event->ID; ?>" <?php selected( $event->ID, (int) $current_relationship ); ?>><?php echo get_the_title( $event->ID ); ?></option>
						<?php
					}
				}
				?>
			</select>
			<?php
		}
	?>
	</select>
</div><!-- end tc-event-relationship-container -->
<?php
}