Replace specific cart item based on product quantity in Woocommerce

Question

I am trying to change the cart content based on the quantity of a product in the cart. I only have 5 products in the shop:

Product_1 => 1 panel,
Product_2 => 12 panels,
Product_3 => 18 panels,
Product_4 => 30 panels,
Product_5 => 60 panels,

They are configured as different products, so no bundles, kits or anything. More than one panel products are obviously cheaper than adding a number of single panels separately.

Then I have also a custom product that calculates the number of panels needed based on floor measures given by the customer and then adds to cart the necessary quantity of single panels.

I Would like to change dynamically the content of the cart when it's reviewed.

So for example, if the floor configurator calculate 54 single panels and added them to the cart, I would like to change the cart item to:

1 Product_4 (30 panels)
1 Product_2 (12 panels)
2 Product_1 (1 panel)
and print a message stating the change.

I've checked different solutions but none of them offer this kind of feature:

So, based on this answer thread, I think I need to use hook woocommerce_before_calculate_totals and implement the logic, but need some help since I am a wordpress dev noob.

Note that the add to cart button is called with Ajax in the floor configurator with:

jQuery("button.ajax_add_to_cart").attr("data-quantity", parseInt(numLozasrealW * numLozasrealH));

Any help is appreciated.

Please post the code you have used to try to achieve your goal (in your original question) if you'd like us to be able to help you. — Justin R.

LoicTheAztec LoicTheAztec · Accepted Answer · 2018-05-22T18:59:58

The code below should do the trick, It will replace the custom product (quantity) by your other products. You will have to set your custom product ID, your 5 normal product IDs and your custom text notice.

The code:

add_action( 'woocommerce_add_to_cart', 'action_before_cart', 20, 3 );
function action_before_cart( $cart_item_key, $product_id, $quantity ) {
    // HERE set your specific product ID
    $specific_product_id = 862;

    if( $product_id != $specific_product_id ) return;

    // HERE set your other product IDs related to panels
    $products_panels = array(
        861 => 50, // Product ID => for 50 panels
        860 => 30, // Product ID => for 30 panels
        859 => 18, // Product ID => for 18 panels
        858 => 12, // Product ID => for 12 panels
        857 => 1,  // Product ID => for  1 panel
    );

    // Loop through all "panels" products IDs
    foreach ( $products_panels as $product_id => $panels ) {
        if( $quantity >= $panels ){
            $qty = floor($quantity / $panels);
            $quantity = $quantity % $panels;
            $data = 'Panels: '.$panels.' | Quantity: '.$qty.' | Remain: '.$quantity;
            print_pr($data);
            WC()->cart->add_to_cart( $product_id, $qty );
        }
    }
    // Removing the specific product
    WC()->cart->remove_cart_item( $cart_item_key );

    // HERE set your custom notice text
    wc_add_notice('Here your custom notice text', 'notice');
}

Code goes in function.php file of your active child theme (or active theme). Tested and works.

As you can see below when custom product is added to cart, it's replaced by the other products to match the quantity of panels and display a custom notice:

Replace specific cart item based on product quantity in Woocommerce

1 Answers