WordPress Related Posts Tutorial, Part 2

related-posts-tutorial-02.php

<?php

/* 
 * NOTE: This is a portion of a tutorial:
 *
 * @link https://johnregan3.wordpress.com/how-to-get-wordpress-related-posts
 */

// Run the query.
$query = new WP_Query( $args );

/*
 * NEW STUFF BELOW.
 * 
 * Notice that we'll be repeating some code here.  
 * We'll clean that up in the next step.
 */

// If we have posts, return them.  Else, we'll continue on.
if ( ! empty( $query->posts ) && count( $query->posts ) >= $count ) {
	return $query->posts;
}

// Since we're continuing, relabel our results for clarity.
$posts = $query->posts;

// Update our $args so we don't duplicate any existing posts in the future.
$args['post__not_in'] = wp_list_pluck( $posts, 'ID' );

/*
 * Remove the search for a specific author.
 *
 * This action will be repeated soon with the taxonomy args.
 * Note that we'll make this code more efficient in the next step.
 */
unset( $args['author'] );

// Run a new query, still searching for posts with the same topics and post type.
$query = new WP_Query( $args );

if ( ! empty( $query->posts ) && is_array( $query->posts ) ) {
	$new_posts = $query->posts;

	// Merge new posts with existing posts.
	$posts = $posts + $new_posts;
}

// If we now have enough posts, return them.
if ( ! empty( $posts ) && count( $posts ) >= $count ) {
	// Make sure the new array of posts doesn't exceed the number of posts we need.
	$posts = array_slice( $posts, 0, $count );

	return $posts;
}

/*
 * Remove the search for specific taxonomy terms, leaving
 * only the post type restriction.
 *
 * Note that we'll make this code more efficient in the next step.
 */
unset( $args['tax_query'] );

$query = new WP_Query( $args );

if ( ! empty( $query->posts ) && is_array( $query->posts ) ) {
	$new_posts = $query->posts;
	$posts = $posts + $new_posts;
}

// Make sure we don't exceed the number of $count.
return array_slice( $posts, 0, $count );