Thesis Themes Customization: 8 | Add related post after Post or Page

I will use 1.8 Developer version of Thesis Theme

LogIn to your Dashboard and Go to Thesis > Custom File Editor

 

Select custom_functions.php form drop down menu and Click Edit Selected File.

Place this code below custom_functions.php :

//related post shortcode
function related_posts_shortcode( $atts ) {
    extract(shortcode_atts(array(
        'limit' => '7',
    ), $atts));
    global $wpdb, $post, $table_prefix;
    if ($post->ID) {
        $retval = '
<ul>';
        // Get tags
        $tags = wp_get_post_tags($post->ID);
        $tagsarray = array();
        foreach ($tags as $tag) {
            $tagsarray[] = $tag->term_id;
        }
        $tagslist = implode(',', $tagsarray);
        // Do the query
        $q = "
            SELECT p.*, count(tr.object_id) as count
            FROM $wpdb->term_taxonomy AS tt, $wpdb->term_relationships AS tr, $wpdb->posts AS p
            WHERE tt.taxonomy ='post_tag'
                AND tt.term_taxonomy_id = tr.term_taxonomy_id
                AND tr.object_id  = p.ID
            AND tt.term_id IN ($tagslist)
                AND p.ID != $post->ID
                AND p.post_status = 'publish'
                AND p.post_date_gmt < NOW()
            GROUP BY tr.object_id
            ORDER BY count DESC, p.post_date_gmt DESC
            LIMIT $limit;";
        $related = $wpdb->get_results($q);
        if ( $related ) {
            foreach($related as $r) {
            $retval .= '
    <li><a title="'.wptexturize($r->post_title).'" href="'.get_permalink($r->ID).'">'.wptexturize($r->post_title).'</a></li>
';
        }
        } else {
            $retval .= '
    <li>No related post found :(</li>
';
        }
        $retval .= '</ul>
';
        return $retval;
    }
    return;
}
add_shortcode('related_posts', 'related_posts_shortcode');
function single_post_relatedpost() {
if (is_single()) { ?>
<h3>Related Post:</h3>
<?php echo do_shortcode("[related_posts]"); ?>
<?php }
}
add_action('thesis_hook_after_post', 'single_post_relatedpost');

 Now save it.

[Please comment for any Problem]