Magento 2: Add multiple products to cart programmatically

Question

Following is the event observer for adding multiple products into cart:

<?php

namespace Namespace\Module\Observer;

class ThirdPartyAdd implements \Magento\Framework\Event\ObserverInterface {

    public function __construct(
    \Magento\Store\Model\StoreManagerInterface $storeManager, \Magento\Checkout\Model\Cart $cart, \Magento\Catalog\Model\Product $product, \Magento\Quote\Model\QuoteFactory $quote
    ) {
        $this->_storeManager = $storeManager;
        $this->_cart = $cart;
        $this->_product = $product;
        $this->quote = $quote;
    }

    public function execute(\Magento\Framework\Event\Observer $observer) {


        if (isset($_POST['submit']) && $_POST['submit'] == 'Submit') {
            for ($i = 0; $i < sizeof($_POST['prod_id']); $i++) {

                $qty = $_POST['prod_qty'][$i];

                $product = $this->_product->load($_POST['prod_id'][$i]);

                $product_type = $product->getTypeID();

                if($product_type == 'configurable') {
                    $simple_products = $product->getTypeInstance()->getUsedProducts($product); //get all simple products
                    $attributes = $product->getTypeInstance(true)->getConfigurableAttributesAsArray($product); //get all possible attributes

                    foreach ($simple_products as $simple_product) {
                        $super_attributes = array();
                        foreach ($attributes as $attribute) {
                            $text = $simple_product->getAttributeText('size');
                            //echo $text;
                            $t1 = 'Black';
                            $t2 = 'M';
                            foreach ($attribute['values'] as $value) {
                            $super_attributes[$attribute['attribute_id']] = $value['value_index'];
                                if ($value['label'] == $t1) {
                                    $super_attributes[$attribute['attribute_id']] = $value['value_index'];
                                }
                                if ($value['label'] == $t2) {
                                    $super_attributes[$attribute['attribute_id']] = $value['value_index'];
                                }
                            }
                        }
                    }
                    $this->_cart->addProduct($product, array(
                        'qty' => $_POST['prod_qty'][$i],
                        'super_attribute' => $super_attributes
                    ));
                    $this->_cart->save();
                }
            }
        }
    }

}

When above code is executed and cart is empty only one product is added to cart with summation of quantity for all the product.

For eg if I add: Prod 1 - 2 quantity Prod 2 - 1 quantity

Cart will contain prod 1 with 3 quantity.

This only happens if cart is empty unless cart is empty code will work as expected.

Please let me know what I am missing here.

Answer 1

You have to use ProductFactory to load product.

protected $product;

public function __construct(
\Magento\Framework\App\Action\Context $context, \Magento\Framework\Data\Form\FormKey $formKey, \Magento\Checkout\Model\Cart $cart, \Magento\Catalog\Model\ProductFactory $product) {
    $this->formKey = $formKey;
    $this->cart = $cart;
    $this->product = $product;
}

public function postSaveAndFinalize($param) {
    $params[0] = array(
        'form_key' => $this->formKey->getFormKey(),
        'product' => 2,
        'qty' => 1
    );
    $params[1] = array(
        'form_key' => $this->formKey->getFormKey(),
        'product' => 1,
        'qty' => 1
    );

    foreach ($params as $product) {
        //Load the product based on productID
        $productModel = $this->product->create();
        $productModel->load($product['product']);
        $this->cart->addProduct($productModel, $product);
    }
    $this->cart->save();
}

In this way you can add multiple products into cart.

Answer 2

Since you are running in loop new instance of product is not created so you are getting the old product instance again which increase the qty

Get new product instance every time.

$productModel = $this->_product->create();
$product = $productModel->load($_POST['prod_id'][$i]);

Answer 3

You'd place cart save() out of products iteration

Example

foreach ($products as $product){
    // ...
    $this->_cart->addProduct(...)
}
$this->_cart->save();

Source: https://magento.stackexchange.com/a/232665/3566