WordPress – Dynamically injecting menu items using Walker Class

I am trying to pull in some dynamic (non-WP) content to populate a menu in WordPress. For this I’ve extended the Walker Class as shown here:

http://www.kriesi.at/archives/improve-your-wordpress-navigation-menu-output

So my Menu would look like

• Home
• Blog
• News
• Features
• competitions –
  • Comp1
  • Comp2

Where Comp1 and Comp2 are pulled from a DB on a seperate site. They are just links to an external site, so the only relevant value is the ‘Comp Title’ and ‘Comp URL’

The main method within my class is :

 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 = '<strong>';
        $append = '</strong>';
        $description  = ! empty( $item->description ) ? '<span>'.esc_attr( $item->description ).'</span>' : '';

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

        if($item->title == 'Competitions')
        {
            $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 .= '</a>';
            $item_output .= $args->after;

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

            $this->loopComps($output , $args);

        }
        else
        {
            $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 .= '</a>';
            $item_output .= $args->after;

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

and then the loopComps method is:
(getGalleryComps() pulls in the dynamic content)

 function loopComps($output , $args)
    {
        $openComps = $this->getGalleryComps();
        foreach($openComps as $comp)
        {
            $item =  new StdClass;
            $item->ID = 9999;
            $item->post_author = 5;
            $item->post_date = '2012-11-16 10:48:44';
            $item->post_date_gmt = '2012-11-16 10:48:44';
            $item->title = $comp['competition_name'];
            $item->post_type = 'nav_menu_item';
            $item->post_name = $comp['competition_name'];
            $item->post_title = $comp['competition_name'];
            $item->post_excerpt = $comp['competition_name'];
            $item->guid = $comp['competition_name'];
            $item->url = 'http://www.mycomps';
            $item->post_status = 'publish';
            $item->post_parent = 0;
            $item->filter = 'raw';
            $item->menu_item_parent = '6845';
            $item->object_id = '99999';
            $item->object = 'custom';
            $item->type = 'custom';
            $item->classes = array(null , 'menu-item' , 'menu-item-type-custom' , 'menu-item-object-custom');
            $item->menu_order = 6;


            return $this->start_el($output, $item, 1, $args);


        }

    }

This all seems to work fine , expect the $item is never attached to the actual menu. If I print out the $items during the nav menu loop, I can see my dynamic content which I’ve created a ‘psuedo Post’ is there , it just never gets attached to the menu.

Is there an easier way of injecting menu items?

UPDATE 1:

I’ve adjusted loopComps method to be:

 function loopComps($output)
    {
        $openComps = $this->getGalleryComps();

        $output .= '<ul>';
        foreach( $openComps as $openComp )
        {
            $output .= '<li><a href='.$openComp->url.'>'.$openComp['competition_name]'].'</a></li>';
        }
        $output .= '</ul>';

        return $output;
  }

As this does make much more sense , but doesn’t solve the issue, the data is there, but is never shown in the menu.