Custom permalink structure for posts in specific category

Question

Hi I'm trying to rewrite permalink structure for posts in one specific category, the structure should be category name - author name - post title When I use the code below, there is no author name in the URL Please, advise me where am I wrong.

add_filter( 'post_link', 'custom_permalink', 'author_link', 10, 3 );
function custom_permalink( $permalink, $post, $leavename ) {
// Get the category for the post
$category = get_the_category($post->ID);
if (  !empty($category) && $category[0]->cat_name == "Tips" ) {
    $cat_name = strtolower($category[0]->cat_name);
    $author_nickname = get_user_meta( $author_id, 'nickname', true );
    $permalink = trailingslashit( home_url('/'. $cat_name . '/' . 
$author_nickname . '/' . $post->post_name .'/' ) );
}
return $permalink;
}

add_filter( 'category_link', 'custom_category_permalink', 10, 2 );
function custom_category_permalink( $link, $cat_id ) {
$slug = get_term_field( 'slug', $cat_id, 'category' );
if ( ! is_wp_error( $slug ) && 'tips' === $slug ) {
    $link = home_url( user_trailingslashit( '/tips/', 'category' ) );
}
return $link;
}

add_action( 'init', 'custom_rewrite_rules' );
function custom_rewrite_rules() {
add_rewrite_rule(
    'tips(?:/page/?([0-9]{1,})|)/?$',
    'index.php?category_name=tips&paged=$matches[1]',
    'top' // The rule position; either 'top' or 'bottom' (default).
);

add_rewrite_rule(
'tips/\d+/([^/]+)(?:/([0-9]+))?/?$', // <- here, add the \d+/
'index.php?category_name=tips&name=$matches[1]&page=$matches[2]',
'top'
);
}

Answer 1

This code works good for me:

 add_filter( 'post_link', 'custom_permalink', 'author_link', 10, 3 );
 function custom_permalink( $permalink, $post, $leavename ) {
  // Get the category for the post
  $category = get_the_category($post->ID);
  if (  !empty($category) && $category[0]->cat_name == "Tips" ) {
    $cat_name = strtolower($category[0]->cat_name);
    $authordata = get_userdata( $post->post_author );
        $author     = $authordata->user_nicename;
    $permalink = trailingslashit( home_url('/'. $cat_name . '/' . $author . '/' .          
$post->post_name .'/' ) );
}
return $permalink;
}

add_filter( 'category_link', 'custom_category_permalink', 10, 2 );
function custom_category_permalink( $link, $cat_id ) {
$slug = get_term_field( 'slug', $cat_id, 'category' );
if ( ! is_wp_error( $slug ) && 'tips' === $slug ) {
    $link = home_url( user_trailingslashit( '/tips/', 'category' ) );
}
return $link;
}

add_action( 'init', 'custom_rewrite_rules' );
function custom_rewrite_rules() {
add_rewrite_rule(
    'tips(?:/page/?([0-9]{1,})|)/?$',
    'index.php?category_name=tips&paged=$matches[1]',
    'top' // The rule position; either 'top' or 'bottom' (default).
);

add_rewrite_rule(
'tips/\d+/([^/]+)(?:/([0-9]+))?/?$', // <- here, add the \d+/
'index.php?category_name=tips&name=$matches[1]&page=$matches[2]',
'top'
);
}