Avoid combining products in cart

Question

With Drupal 8 / Drupal Commerce 2, I can't find a way to disable product combining in cart (same products in cart appears on the same line with quantity > 1). In my use case I never want this to happen.

I found that in

/modules/contrib/commerce/modules/cart/src/Form/AddToCartForm.php

...we have a submitForm method which calls

$this->cartManager->addOrderItem($cart, $order_item, $form_state->get(['settings', 'combine']);

So it seems like my form needs to have a combine variable set to FALSE.

How could I set this variable or override

public function addOrderItem(OrderInterface $cart, OrderItemInterface $order_item, $combine = TRUE, $save_cart = TRUE);

...in

/modules/contrib/commerce/modules/cart/src/CartManagerInterface.php

...to define the default value of $combine to FALSE ?

Thanks

Answer 1

I could achieve this by implementing hook_form_alter on add to cart form (in a custom module) and setting combine like this :

$form_state->set(['settings', 'combine'], FALSE);

Answer 2

Edge-case, but if you're adding items to the cart programmatically from a custom form, here's what I found to have worked.

$cart_manager = \Drupal::service('commerce_cart.cart_manager');

$line_item = $cart_manager->addEntity($cart, $variationobj, $quantity, FALSE, TRUE);

This will call addEntity() and set Combined to FALSE.