Use wp_nav() to output href=slug instead of URL using Crawler class

Hello i am using the crawler class to customise the output of the wp_nav menu.

I need it to give me the slug in the href="#" instead of the url.
I coud use the custom link in the back-end (appearance/menus) but i wish to use the page , categories , and post items option instead of having to create a custom link.

Because i am building a Parallax site i need it o navigate through the various sections.

So far i got this in my functions.php :

<?php
class description_walker extends Walker_Nav_Menu
{
function start_el(&$output, $item, $depth, $args)
{
global $wp_query;
$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

$class_names = $value = '';

$classes = empty( $item->classes ) ? array() : (array) $item->classes;

$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) );
$class_names = ' class="'. esc_attr( $class_names ) . '"';

$output .= $indent . '<li id="menu-item-'. $item->ID . '"' . $value . $class_names .'>';

$attributes .= ! empty( $item->attr_title ) ? ' title="' . esc_attr( $item->attr_title ) .'"' : '';
$attributes .= ! empty( $item->target ) ? ' target="' . esc_attr( $item->target ) .'"' : '';
$attributes .= ! empty( $item->xfn ) ? ' rel="' . esc_attr( $item->xfn ) .'"' : '';
$attributes .= ! empty( $item->url ) ? ' href="#' . esc_attr( $item->url ) .'"' : '';

$prepend = '<div class="menu-item-info"><h3>';
$append = '</h3>';
$description = ! empty( $item->description ) ? '<p>'.esc_attr( $item->description ).'</p></div>' : '';

if($depth != 0)
{
$description = $append = $prepend = "";
}

$item_output = $args->before;
$item_output .= '<a'. $attributes .'>';
$item_output .= $args->link_before .$prepend.apply_filters( 'the_title', $item->title, $item->ID ).$append;
$item_output .= $description.$args->link_after;
$item_output .= '';
$item_output .= $args->after;

$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}
}
?>

If any one can give me hand with this it would be SUPER :smiley:

Thanx