Product Prev/Next Navigation Bug

Too bad, that seemed like a really cool feature, but as it currently works, I feel that it is more confusing to the end user than it is helpful for product navigation.

I do understand that a solution would be quite complex. Thanks for providing additional insight into potential pitfalls (product in multiple categories, etc). If I have time, I’ll try to find a way to get this to work how I’d like and will post back here if I come up with a solution that can be applied universally.

Maybe something like how it’s done here: https://gist.github.com/georgybu/4285005 instead of using get_next_post() and get_previous_post()

Anyway, thanks for quick response and great job with the Woodmart theme – overall I love it.

Thanks! In case this is useful to anyone else out there, I got this working to suit my needs for now by using the code below. As mentioned above, if a product is in more than one category, there will be issues. For me though, my products are mostly only in one category each.

Based on this: https://wordpress.stackexchange.com/a/204270/145210

add_filter('get_next_post_sort',  'filter_next_and_prev_post_sort');
add_filter('get_previous_post_sort',  'filter_next_and_prev_post_sort');
function filter_next_and_prev_post_sort($sort) {
    $op = ('get_previous_post_sort' == current_filter()) ? 'DESC' : 'ASC';
    $sort = "ORDER BY p.post_title ".$op ." LIMIT 1";
    return $sort;
}

add_filter( 'get_next_post_join', 'navigate_in_same_taxonomy_join', 20);
add_filter( 'get_previous_post_join', 'navigate_in_same_taxonomy_join', 20 );
function navigate_in_same_taxonomy_join() {
  global $wpdb;
  return " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id INNER JOIN $wpdb->term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id";
}

add_filter( 'get_next_post_where' , 'filter_next_and_prev_post_where' );
add_filter( 'get_previous_post_where' , 'filter_next_and_prev_post_where' );
function filter_next_and_prev_post_where( $original ) {
  global $wpdb, $post;
  $where = '';
  $taxonomy   = 'product_cat';
  $op = ('get_previous_post_where' == current_filter()) ? '<' : '>';

  if ( ! is_object_in_taxonomy( $post->post_type, $taxonomy ) ) {
    return $original ;
  }

  $term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );

  $term_array = array_map( 'intval', $term_array );

  if ( ! $term_array || is_wp_error( $term_array ) ) {
    return $original;
  }
  $where = " AND tt.term_id IN (" . implode( ',', $term_array ) . ")";
  return $wpdb->prepare( "WHERE p.post_title $op %s AND p.post_type = %s AND p.post_status = 'publish' $where", $post->post_title, $post->post_type );
}