Question

Is there a way to display an extra text next to the Username if the person has the administrator role?

I just want to display the extra text for this role only, what hook could I use for that?

Answer 1

Yes, you can use the filter the_author, like so:

add_filter( 'the_author', 'author_admin_so_14367149' );

function author_admin_so_14367149( $display_name ) 
{
    // Block the filter in the dashboard (admin area)
    if( is_admin() )
        return $display_name;

    global $authordata;

    // User has administrator role, add string to display name
    if( in_array( 'administrator', $authordata->roles ) )
        $display_name = $display_name . ' (admin)';

    return $display_name;
}

For the comments section, there’s another filter and the checks are different:

add_filter( 'get_comment_author', 'comment_author_admin_so_14367149' );

function comment_author_admin_so_14367149( $author ) 
{
    // Block the filter in the dashboard (admin area)
    if( is_admin() )
        return $author;

    $user = get_user_by( 'login', $author );

    // User has administrator role, add string to display name
    if( in_array( 'administrator', $user->roles ) )
        $author = $author . ' (admin)';

    return $author;
}