Odd class to odd li's within 'sub-menu' ul's

Hello Luke,

I’m sorry that I didn’t respond for two months. Let me improve myself. ??

That’s my fast solution to your problem (but maybe someone find simpler one):

1. Define protected/private variable for your walker class. This is an array with current items counters on every depth level. Because start_lvl method isn’t called before first item of 0 level, you have to fill 0 index of your array by 0 value.
protected $_itemsNoByDepth = array( 0 => 0 );

2. When you start next level you have to set level counter to 0 in start_lvl method. Because first sub-level have $depth value 0 you have add 1 to this value.
$this->_itemsNoByDepth[$depth+1] = 0;

3. Finally you have to iterate proper counter in every occurrence of start_el method. After it you can use this counter to add required classes as a new $classes array indexes. In your case it will be:

$this->_itemsNoByDepth[$depth]++;
if( $depth > 0 && $this->_itemsNoByDepth[$depth] % 2 ) {
 $classes[] = 'odd';
}

but if you’d like to add eg. odd/even classes and classes with consecutive items numbers, you can do sth like:

$this->_itemsNoByDepth[$depth]++;
$classes[] = 'item-no-' . $this->_itemsNoByDepth[$depth];
$classes[] = 'item-' . ( $this->_itemsNoByDepth[$depth] % 2 ? 'odd' : 'even' );

Remember to put above code between $classes and $class_names variable declarations.

After these three steps your code should looks like that:

class Menu_With_Description extends Walker_Nav_Menu
{

        protected $_itemsNoByDepth = array( 0 => 0 );

    	function start_lvl(&$output, $depth) {
            $this->_itemsNoByDepth[$depth+1] = 0;
        	$indent = str_repeat("\t", $depth);
        	$output .= "\n$indent<ul class=\"sub-menu level-".$depth."\">\n";
    	}
    	function end_lvl(&$output, $depth) {
        	$indent = str_repeat("\t", $depth);
        	$output .= "$indent<div class=\"fix\"></div></ul><div class=\"fix\"></div>\n";
    	}

    /**
     * Start the element output.
     *
     * @param  string $output Passed by reference. Used to append additional content.
     * @param  object $item   Menu item data object.
     * @param  int $depth     Depth of menu item. May be used for padding.
     * @param  array $args    Additional strings.
     * @return void
     */
     function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output )
{
    $id_field = $this->db_fields['id'];
    if ( is_object( $args[0] ) ) {
        $args[0]->has_children = ! empty( $children_elements[$element->$id_field] );
    }
    return parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
}

    function start_el(&$output, $item, $depth, $args)
    {

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

        $this->_itemsNoByDepth[$depth]++;
        if( $depth > 0 && $this->_itemsNoByDepth[$depth] % 2 ) {
            $classes[] = 'odd';
        }

        $class_names = join(
            ' '
        ,   apply_filters(
                'nav_menu_css_class'
            ,   array_filter( $classes ), $item
            )
        );

        if ($args->has_children && $depth == 0){
        ! empty ( $class_names )
            and $class_names = ' class="'. esc_attr( $class_names ) . ' has_children"';
        }else{
         ! empty ( $class_names )
            and $class_names = ' class="'. esc_attr( $class_names ) . '"';
        }

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

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

        // insert description for top level elements only
        // you may change this
        $description = ( ! empty ( $item->description ) and 0 == $depth )
            ? '<span class="description">' . esc_attr( $item->description ) . '</span>' : '';

        $title = apply_filters( 'the_title', $item->title, $item->ID );
if ( $depth == 0 ) {//top level items
            $item_output = $args->before
            ."<div class='parent'><div class='cat-icon'></div><div class='title-desc'>"
            . "<a $attributes>"
            . $args->link_before
            . $title
            . '</a><br>'
            . $args->link_after
            . $description
            . '</div></div>'
            . $args->after;
        }else{//everything else
        $item_output = $args->before
            . "<a $attributes>"
            . $args->link_before
            . $title
            . '</a> '
            . $args->link_after
            . $args->after;
        }
        // Since $output is called by reference we don't need to return anything.
        $output .= apply_filters(
            'walker_nav_menu_start_el'
        ,   $item_output
        ,   $item
        ,   $depth
        ,   $args
        );
    }

}

Thanks man!!

Absolutely perfect bud, exactly what I wanted. And thanks for providing the edited walker function it’s much appreciated.

Luke