Change author base slug for different roles

Is it possible to change the author base slug according to his role? For example, authors get example.com/ninja/%username% and subscribers get example.com/trainee/%username%?

I am thinking of something like:

add_action('init', 'set_new_author_base');
function set_new_author_base() {
  global $wp_rewrite;

  if($user->role == 'subscriber')
    $author_slug = 'trainee';
    $wp_rewrite->author_base = $author_slug;
  } elseif($user->role == 'author') {
    $author_slug = 'ninja';
    $wp_rewrite->author_base = $author_slug;
  }
}

It should work for unregistered visitors if they browse the site and it should work for the logged in authors and subscribers themselves.

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

In your example, the author rewrite pattern changes from /author/[authorname]/ to /[author_level]/[author_name]/. If we allow [author_level] to be anything, we will get into conflict with the rules for pages, because /[anything]/[anything]/ can be either an author archive or a regular subpage.

For this reason, my solution assumes you have a limited number of author levels, so we can explicitly put them in the rewrite rules. So /ninja/[anything]/ will be an author archive, but /not-ninja/[anything]/ will be a regular page.

Changing the URL structure always consists of two parts: changing the URLs that WordPress will accept and changing the URLs that WordPress will generate. First we will change the URLs that WordPress will accept by introducing a new rewrite tag and setting our author base to that tag.

// I assume you define these somewhere, this is just to make the example work
$wpse17106_author_levels = array( 'trainee', 'ninja' );

add_action( 'init', 'wpse17106_init' );
function wpse17106_init()
{
    global $wp_rewrite;
    $author_levels = $GLOBALS['wpse17106_author_levels'];

    // Define the tag and use it in the rewrite rule
    add_rewrite_tag( '%author_level%', '(' . implode( '|', $author_levels ) . ')' );
    $wp_rewrite->author_base = '%author_level%';
}

If you check the resulting rewrite rules with my Rewrite Analyzer you will notice that it contains extra rules for the plain /[author-level]/ pages. This happens because WordPress generates rules for each directory part that contains a rewrite tag, like %author_level%. We don’t need these, so filter out all author rewrite rules that don’t contain an author_name:

add_filter( 'author_rewrite_rules', 'wpse17106_author_rewrite_rules' );
function wpse17106_author_rewrite_rules( $author_rewrite_rules )
{
    foreach ( $author_rewrite_rules as $pattern => $substitution ) {
        if ( FALSE === strpos( $substitution, 'author_name' ) ) {
            unset( $author_rewrite_rules[$pattern] );
        }
    }
    return $author_rewrite_rules;
}

Now WordPress should accept URLs using this new pattern. The only thing left to do is change the URLs it generates when it creates a link to an author archive. For that you can hook into the author_link filter, like this very basic example:

add_filter( 'author_link', 'wpse17106_author_link', 10, 2 );
function wpse17106_author_link( $link, $author_id )
{
    if ( 1 == $author_id ) {
        $author_level = 'ninja';
    } else {
        $author_level = 'trainee';
    }
    $link = str_replace( '%author_level%', $author_levels, $link );
    return $link;
}

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0