add dynamic url to menu item to wp nav menu with replacement strings

dynamic_url_nav_menu_url.php

/*--------------------------------------------------------------
# add dynamic profile link to main menu. smart and simple! just do a string replace on a menu link item
# add a link item and set the url to --url-- and give it a css class of iscurrent
--------------------------------------------------------------*/

function wp_dynamic_profile_link( $menu ){

    //$link may have to be changed to your current users profile or author page or whatever...
    //i had a post type profile link to each user
    
    $link = get_author_posts_url( get_current_user_id() );
    
    //link menu item appends http:// for us so we need to take it off ours.
    $link = str_replace('http://', '', get_permalink($link));
    
    //make menu current-item if it is current page
    $actual_link = "$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
    if($actual_link == $link){
	    $menu = str_replace('iscurrent', 'current-menu-item', $menu);
    }
    
    return $menu = str_replace('--url--', $link, $menu );
}
add_filter( 'wp_nav_menu', 'wp_dynamic_profile_link' );