Related posts do not display posts that match the category?

Please help me, I haven’t found a solution in two days. I want to make related posts widgets based on the category of posts opened by visitors. I want to place it in the sidebar.

I have entered the code below into the child theme function.php, but the list of posts that appear is the most recent post.

Link this code: https://wordpress.stackexchange.com/a/307493/159482

function example_cats_related_post() {
$post_id = get_the_ID();
    $cat_ids = array();
    $categories = get_the_category( $post_id );
    if(!empty($categories) && is_wp_error($categories)):
        foreach ($categories as $category):
            array_push($cat_ids, $category->term_id);
        endforeach;
    endif;
    $current_post_type = get_post_type($post_id);
    $query_args = array( 
        'category__in'   => $cat_ids,
        'post_type'      => $current_post_type,
        'post__not_in'    => array($post_id),
        'posts_per_page'  => '3'
     );
    $related_cats_post = new WP_Query( $query_args );
    if($related_cats_post->have_posts()):
         while($related_cats_post->have_posts()): $related_cats_post->the_post(); ?>
            <ul>
                <li>
                    <a>">
<?php the_title(); ?>
                    </a>
                </li>
            </ul>
        <?php endwhile;
        // Restore original Post Data
        wp_reset_postdata();
     endif;
}

and this caller code:

<?php example_cats_related_post() ?>

know this is not an easy thing for beginners, but please give me a hint. I have also succeeded in displaying the related post under the article as I wish, you can check on my experiment blog: mangedu.me

Thank you in advance, I really hope to get a clear answer.

• This topic was modified 7 years by renomureza.
• This topic was modified 7 years by renomureza.
• This topic was modified 7 years by renomureza.

Hi Catalin,

that’s not what I mean. I want to display posts based on categories from posts opened by users.