The goal here is to create a Top Level Menu that automatically pulls child pages without the need to manually add them to said menu. I didn't know any other way to accomplish this without a walker, of which I'm not very familiar with. I was playing around with it and was able to get the submenus to work with this. The submenu gets added at the bottom of start_el/** The Walker **/class fitz_and_the_tantrums extends Walker_Nav_Menu {    // add main/sub classes to li's and links     function start_el( &$output, $item, $depth, $args ) {        global $wp_query;        $indent = ( $depth > 0 ? str_repeat( \t, $depth ) : '' ); // code indent        // passed classes        $classes = empty( $item->classes ) ? array() : (array) $item->classes;        $class_names = esc_attr( implode( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) ) );        // build html        $output .= $indent . '<li id=nav-menu-item-'. $item->ID . ' class=' . $class_names . '>';        // link attributes        $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        ) .'' : '';        $attributes .= ' class=menu-link ' . ( $depth > 0 ? 'sub-menu-link' : 'main-menu-link' ) . '';        $item_output = sprintf( '%1$s<a%2$s>%3$s%4$s%5$s</a>%6$s',            $args->before,            $attributes,            $args->link_before,            apply_filters( 'the_title', $item->title, $item->ID ),            $args->link_after,            $args->after        );        // build html        $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );        if(nav_hasChildren($item->object_id)){            $output .= '<ul class=submenu>';            ob_start();                wp_list_pages(                    array(                        'child_of'  => $item->object_id,                        'depth'     => 1,                        'title_li'  => ''                    )                );            $output .= ob_get_clean();            $output .= '</ul>';        }    }}/** Check if item has Children **/function nav_hasChildren($pid) {    $children = get_pages('child_of='.$pid);    if($children)        return true;    else        return false;}Is there a way to minimize the needed code, or do I absolutely need to set everything so that the Walker can function properly?
Automatic submenu
php;wordpress