Related Posts for Custom Post Type Imported from 2nd Site (Harvard Primary Care, Rospods)

I recently updated a medical school primary care website to a new theme and merged the schools podcast stie into the new site. The old podcast site had a related post feature and I needed Related Posts for Custom Post Type for the new site. I found a nice writeup on “how to” add them at How to display related posts without a plugin but after I implemented it, it didn’t work properly because I had created the Custom Post Type and then imported the Rospod posts as a regular post type before converting them to the custom post type with a plugin. That resulted in both category and tag overlap between the regular post type and the rospod post type.

The two main changes were explictly calling the post type:

	'post_type' => 'rospod',

and then exiting the function if the current post type in the query was not rospod:

	if ( 'rospod' != get_post_type() ) {
        return;
    }

The resulting code for the functions.php file looked like this:

	/**
 * Related posts
 * 
 * @global object $post
 * @param array $args
 * @return
 */
function wcr_related_posts($args = array()) {
    global $post;

    // default args
    $args = wp_parse_args($args, array(
        'post_id' => !empty($post) ? $post->ID : '',
        'taxonomy' => 'post_tag',
        'limit' => 3,
        'post_type' => 'rospod',
        'orderby' => 'date',
        'order' => 'DESC'
    ));

    // check taxonomy
    if (!taxonomy_exists($args['taxonomy'])) {
        return;
    }

    // post taxonomies and post types
    $taxonomies = wp_get_post_terms($args['post_id'], $args['taxonomy'], array('fields' => 'ids'));
    
    if (empty($taxonomies)) {
        return;
    }
	if ( 'rospod' != get_post_type() ) {
        return;
    }

    // query
    $related_posts = get_posts(array(
        'post__not_in' => (array) $args['post_id'],
        //'post_type' => $args['post_type'],
        'post_type' => 'rospod',
        'tax_query' => array(
            array(
                'taxonomy' => $args['taxonomy'],
                'field' => 'term_id',
                'terms' => $taxonomies
            ),
        ),
        'posts_per_page' => $args['limit'],
        'orderby' => $args['orderby'],
        'order' => $args['order']
    ));

    include( locate_template('related-posts-template.php', false, false) );

    wp_reset_postdata();
}
add_action( 'astra_entry_content_after','wcr_related_posts' );

One of the reasons this worked so well is that I had converted the site to the Astra theme. See my post Medical School – Primary Care Elementor & Astra Site Rewrite. The Astra theme has a lot of hooks that allow us to add content programmatically so I was able to use the “astra_entry_content_after” hook to add the content of the related-posts-template.php file to the posts page.