Related posts

Continuing from the Basic usage tutorial, let's say that when viewing a single post, you don't want to show the connected page, but other posts connected to the same page.

First, you will have to create a function in your functions.php theme file:

<?php
function get_related_posts( $post_id ) {
	// Get the page connected to the post
	$related_pages = get_posts( array(
		'post_type' => 'page',
		'connected_from' => $post_id,
		'posts_per_page' => 1,
		'suppress_filters' => false
	) );

	// No related posts if there's no page relating them
	if ( empty( $related_pages ) )
		return array();

	// Get the other posts connected to the same page
	return get_posts( array(
		'post_type' => 'post',
		'post__not_in' => array( $post_id ),
		'connected_to' => $related_pages[0]->ID,
		'nopaging' => true,
		'suppress_filters' => false
	) );
}

It takes a post id and returns an array of related posts.

Now that we have the logic for finding related posts, all we need to do is display them:

<?php
$related_posts = get_related_posts( get_queried_object_id() );

echo '<ul>';
foreach ( $related_posts as $post ) {
	setup_postdata( $post );

	echo '<li>';
	the_title();
	echo '</li>';
}
echo '</ul>';

wp_reset_postdata();

The above code would go in single.php