WooCommerce: how to add multiple products to cart at once?

Question

I need a "get products A, B and C for $xxx" special offer, products A, B and C must be available on their own, and the bundle is a special offer accessible through a coupon code.

On a marketing page hosting outside my site, I would like a button leading to my site that carries a query string like ?add-to-cart=244,249,200 so that once on my site, all bundle products are already added to the cart (instead of adding them one by one which sounds unacceptably tedious).

If not possible, then at least I'd like a landing page on my site with a single button adding all bundle products to cart at once.

I couldn't find working solutions googling around (here's one example). Any suggestion?

Answer 1

After some research I found that DsgnWrks wrote a hook that does exactly this. For your convenience, and in case the blog goes offline, I bluntly copied his code to this answer:

function woocommerce_maybe_add_multiple_products_to_cart( $url = false ) {
    // Make sure WC is installed, and add-to-cart qauery arg exists, and contains at least one comma.
    if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
        return;
    }

    // Remove WooCommerce's hook, as it's useless (doesn't handle multiple products).
    remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );

    $product_ids = explode( ',', $_REQUEST['add-to-cart'] );
    $count       = count( $product_ids );
    $number      = 0;

    foreach ( $product_ids as $id_and_quantity ) {
        // Check for quantities defined in curie notation (<product_id>:<product_quantity>)
        // https://dsgnwrks.pro/snippets/woocommerce-allow-adding-multiple-products-to-the-cart-via-the-add-to-cart-query-string/#comment-12236
        $id_and_quantity = explode( ':', $id_and_quantity );
        $product_id = $id_and_quantity[0];

        $_REQUEST['quantity'] = ! empty( $id_and_quantity[1] ) ? absint( $id_and_quantity[1] ) : 1;

        if ( ++$number === $count ) {
            // Ok, final item, let's send it back to woocommerce's add_to_cart_action method for handling.
            $_REQUEST['add-to-cart'] = $product_id;

            return WC_Form_Handler::add_to_cart_action( $url );
        }

        $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
        $was_added_to_cart = false;
        $adding_to_cart    = wc_get_product( $product_id );

        if ( ! $adding_to_cart ) {
            continue;
        }

        $add_to_cart_handler = apply_filters( 'woocommerce_add_to_cart_handler', $adding_to_cart->get_type(), $adding_to_cart );

        // Variable product handling
        if ( 'variable' === $add_to_cart_handler ) {
            woo_hack_invoke_private_method( 'WC_Form_Handler', 'add_to_cart_handler_variable', $product_id );

        // Grouped Products
        } elseif ( 'grouped' === $add_to_cart_handler ) {
            woo_hack_invoke_private_method( 'WC_Form_Handler', 'add_to_cart_handler_grouped', $product_id );

        // Custom Handler
        } elseif ( has_action( 'woocommerce_add_to_cart_handler_' . $add_to_cart_handler ) ){
            do_action( 'woocommerce_add_to_cart_handler_' . $add_to_cart_handler, $url );

        // Simple Products
        } else {
            woo_hack_invoke_private_method( 'WC_Form_Handler', 'add_to_cart_handler_simple', $product_id );
        }
    }
}

// Fire before the WC_Form_Handler::add_to_cart_action callback.
add_action( 'wp_loaded', 'woocommerce_maybe_add_multiple_products_to_cart', 15 );


/**
 * Invoke class private method
 *
 * @since   0.1.0
 *
 * @param   string $class_name
 * @param   string $methodName
 *
 * @return  mixed
 */
function woo_hack_invoke_private_method( $class_name, $methodName ) {
    if ( version_compare( phpversion(), '5.3', '<' ) ) {
        throw new Exception( 'PHP version does not support ReflectionClass::setAccessible()', __LINE__ );
    }

    $args = func_get_args();
    unset( $args[0], $args[1] );
    $reflection = new ReflectionClass( $class_name );
    $method = $reflection->getMethod( $methodName );
    $method->setAccessible( true );

    $args = array_merge( array( $class_name ), $args );
    return call_user_func_array( array( $method, 'invoke' ), $args );
}

It works just like you'd expect, by providing a comma separated list of products. It even works with quantities using ?add-to-cart=63833:2,221916:4

I was, and am still looking for a 'pure' solution that allows to add multiple products to the cart without having to install a plugin or add custom actions. But for many, the above might be an appropriate solution