[Plugin: Posts 2 Posts] How to call two post types connected in one query?

How about something like this:

$query = new WP_Query( array(
  'post_type' => 'post',
  'each_connected_to' => array(
    'post_type' => 'writer',
    'orderby' => 'title',
    'order' => 'asc'
  ),
  'each_connected_meta' => array()  // optional
) );

while ( $query->have_posts() ) : $query->the_post();
  the_title();

  foreach ( $post->connected_to as $p2p_id => $writer ) {
    echo $writer->post_title;
  }
endwhile;

As you can see, each $post has a connected_to property, which is an array of connected posts.

Note that this is not implemented yet; I’m just brainstorming.

Try the development version (0.6-alpha).

So you have 'each_connected', 'each_connected_to' and 'each_connected_from', with matching $post->connected, $post->connected_to and $post->connected_from.

Also, you can nest it as many levels as you want:

$posts = get_posts( array(
	'post_type' => 'post',
	'nopaging' => true,
	'each_connected' => array(
		'post_type' => 'writer',
		'nopaging' => true,
		'each_connected' => array(
			'post_type' => 'genre',
			'nopaging' => true,
		),
	),
	'suppress_filters' => false
) );

echo "<pre>";
foreach ( $posts as $post ) {
	echo $post->post_title . "\n";

	foreach ( $post->connected as $writer ) {
		echo $writer->post_title . "\n";

		foreach ( $writer->connected as $genre ) {
			echo $genre->post_title . "\n";
		}
	}
}
echo "</pre>";

Does it work properly if you just do the inner query? How about if you also add a ‘connected’ query var to the inner query?

I mean like this:

$query = new WP_Query( array(
                    'post_type' => 'writter',
                    'nopaging' => true,
                    'cat' => '3',
            ) );

then, like this:

$query = new WP_Query( array(
                    'connected' => $some_post_id,
                    'post_type' => 'writter',
                    'nopaging' => true,
                    'cat' => '3',
            ) );