Sort on stock in woocommerce

gistfile1.txt

// Add a new sorting option for pushing out-of-stock products last
add_filter( 'woocommerce_get_catalog_ordering_args', 'custom_sort_out_of_stock_last', 9999 );
function custom_sort_out_of_stock_last( $args ) {
    // Check if the custom sorting option is selected
    if ( isset( $_GET['orderby'] ) && $_GET['orderby'] === 'instock_last' ) {
        $args['orderby'] = 'meta_value';
        $args['meta_key'] = '_stock_status';
        $args['order'] = 'ASC'; // 'instock' comes before 'outofstock'
    }
    return $args;
}

// Add the sorting option to the dropdown
add_filter( 'woocommerce_default_catalog_orderby_options', 'add_instocks_last_sorting_option' );
add_filter( 'woocommerce_catalog_orderby', 'add_instocks_last_sorting_option' );
function add_instocks_last_sorting_option( $options ) {
    $options['instock_last'] = __( 'Sort by stock status', 'woocommerce' );
    return $options;
}

// Modify the product query to respect stock status
add_filter( 'woocommerce_product_query_meta_query', 'include_out_of_stock_meta_query', 9999, 2 );
function include_out_of_stock_meta_query( $meta_query, $query ) {
    if ( isset( $_GET['orderby'] ) && $_GET['orderby'] === 'instock_last' ) {
        $meta_query[] = array(
            'key'     => '_stock_status',
            'compare' => 'EXISTS',
        );
    }
    return $meta_query;
}


// Remove the default sorting dropdown
remove_action( 'woocommerce_before_shop_loop', 'woocommerce_catalog_ordering', 30 );

// Add a custom sorting list
add_action( 'woocommerce_before_shop_loop', 'custom_sorting_list', 30 );
function custom_sorting_list() {
    // Define sorting options
    $sorting_options = array(
        'instock_last' => __( 'Op voorraad', 'woocommerce' ),
        'menu_order'   => __( 'Standaard volgorde', 'woocommerce' ),
        'popularity'   => __( 'Populariteit', 'woocommerce' ),
        'date'         => __( 'Nieuwste', 'woocommerce' ),
        'price'        => __( 'Prijs laag > hoog', 'woocommerce' ),
        'price-desc'   => __( 'Prijs hoog > laag', 'woocommerce' ),
    );

    // Get the current sorting option
    $current_orderby = isset( $_GET['orderby'] ) ? wc_clean( $_GET['orderby'] ) : 'menu_order';

    // Output the sorting list
    echo '<h4>Sorteer producten op:</h4>';
    echo '<ul class="custom-sorting-list">';
    foreach ( $sorting_options as $value => $label ) {
        $active_class = $current_orderby === $value ? 'active' : '';
        $url = add_query_arg( 'orderby', $value, remove_query_arg( 'paged' ) );
        echo '<li class="' . esc_attr( $active_class ) . '">';
        echo '<a href="' . esc_url( $url ) . '">' . esc_html( $label ) . '</a>';
        echo '</li>';
    }
    echo '</ul>';
}