WooCommerce: Allow adding multiple products to the cart via the add-to-cart query string

If you’re not familiar, WooCommerce offers a way to link to the checkout/cart page and automatically add a product to the cart (h/t Justin). You can create a link like so:

$product_id = 55;
$url = esc_url_raw( add_query_arg( 'add-to-cart', $product_id, wc_get_checkout_url() ) );

I recently (somewhat annoyingly) discovered that while that works fairly well, there was no way to do this for multiple products. So I’ve created a snippet that will allow you to do so by adding a comma-separated list of products ids:

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 $product_id ) {
        if ( ++$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 );
}

Now you can get the cart url for multiple products like so:

$product_ids = implode( ',', array( 1, 2, 55 ) );
$url = esc_url_raw( add_query_arg( 'add-to-cart', $product_ids, wc_get_checkout_url() ) );
UPDATE 04-21-17: I have updated the snippet to work with non-simple product types. (See the `woo_hack_invoke_private_method()` function). As indicated by the function name, this is a hack to get access to WooCommerce protected/private methods. Your milage may vary when using this snippet.

14 Comments on “WooCommerce: Allow adding multiple products to the cart via the add-to-cart query string

  1. Hi, Thanks for the code. Can you please share a code for variable products also? Thanks

  2. Like this: 3072&variation_id=3083&attribute_pa_yuzukolcusu=09&quantity=3,3072&variation_id=3082&attribute_pa_yuzukolcusu=11&quantity=3

  3. I didn’t get where to put this piece of code:
    $product_ids = implode( ‘,’, array( 1, 2, 55 ) );
    $url = esc_url_raw( add_query_arg( ‘add-to-cart’, $product_ids, wc_get_checkout_url() ) );
    Within the snippet?

    • That is highly contextual to your project. You would use it wherever you need to output a url that adds multiple products to the cart. (where 1, 2, 55 equals the product ids you want to be added)

  4. Ok, but… should I put that piece of code within your snippet? Outside?

  5. Thanks JT for your reply! I assumed it was so… An example, please?

  6. What good code, but how do I for the quantity of several products?

    • Hi Wladimick Diaz,
      Did you find a way to achieve this (multiple products with quantities for each)? I’m struggling with this :-/
      Thanks!!

  7. Thanks for updating the snippet to handle multiple variable products! Legendary!

    Have you considered making an Admin facing UI to allow creating these URLs by selecting products? This would make a nice plugin.

    Cheers,
    Jason

  8. Hi,

    When i use your code it adds two of each product i want to add to the cart.

    Can you explain why?

    • I already figured it out.

      I am using jQuery to create the add-to-cart link, and i was redirecting to the wrong page.

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