updating product subtotal in cart contents

Question

I've trying to write my campaign plugin. Here is the problem,

I want to update, line_subtotal and line_total in a product in $cart_items.

1- woocommerce_cart_product_subtotal is not really working.

2- I tried to redefine array's element by cart_item_key

                foreach($cartItems as $hash => $perProduct)
                { 
                    if($perProduct['product_id'] = $lastItemsProductId)
                    {
                        if($lastItemsQuantity > 1)
                        {
                            $lineSubtotal = data_get($lastItemInCart, 'line_subtotal');
                            $lineTotal = data_get($lastItemInCart, 'line_total');
                            $newQuantity = $lastItemsQuantity-1; 
                            
                            $lastItemInCart['line_subtotal'] = $newQuantity * $lastItemsPrice;
                            $lastItemInCart['line_total'] = $newQuantity * $lastItemsPrice;  
                            $cartItems[$lastItemsKey] = $lastItemInCart;  
 
                            WC()->cart->calculate_totals();
             
 
                            
                        } else {
                             
                        }
                    }
                     
                }

Also this function runs, in woocommerce_before_calculate_totals action.

When i try it, with woocommerce_get_cart_contents filter, my cart empty itself .

3- The scenario :

When i add A product, (if is selected by system) and if quantity is more than 2, i want to make discount about this product.

Any helps ? Thanks.

Here is the answer

        /**
         * Add filter for order list 
         *
         * @param [int] $product_subtotal
         * @param [object] $product
         * @param [int] $quantity
         * @param [array] $cart
         * @return void
         */
        public function filterWoocommerceCartProductSubtotal($product_subtotal, $product, $quantity, $cart) : string
        {
            $appliedCoupons  = $cart ? $cart->get_applied_coupons() : null;
            $cartCount = $cart ? count($cart->get_cart()) : 0;
            $cartItems = $cart->get_cart();
            $lastItemInCart = last($cartItems);
            $lastItemsProductId = data_get($lastItemInCart, 'product_id', data_get($lastItemInCart, 'product_id'));
            $lastItemsPrice = $lastItemInCart['data']->get_regular_price();
            $lastItemsQuantity = data_get($lastItemInCart, 'quantity');
            $lastItemsKey = data_get($lastItemInCart, 'key');
            
            if( in_array('3al2ode', $appliedCoupons)){  
                if($lastItemsQuantity > 1) {
                    if(@data_get($product,'id') == $lastItemsProductId)
                    {
                        $newSubTotal = 0;
                        $price = $product->get_price();  

                        $newQuantity = $lastItemsQuantity-1; 
                        $quantity = $newQuantity; 
                        $newSubTotal += $price * $quantity;
                
                        return $newSubTotal ? wc_price($newSubTotal) : $product_subtotal; 
                    }
                } 
                
            }  
            return $product_subtotal;
            
        }

The right, filter should be like;

add_filter( 'woocommerce_cart_product_subtotal', [$this,'filterWoocommerceCartProductSubtotal'], 10, 4);

Your question is not entirely clear to me. Is it the intention to adjust the price and the subtotal per line item (per product) in the cart based on the quantity of that product in the cart? — 7uc1f3r, Sep 21 '21 at 07:25
yes, need to update per product. also i added, solution thank you. — Fatih Toprak, Sep 22 '21 at 10:16

score 1 · Answer 1 · answered Sep 21 '21 at 04:48

As per your current scenario - When I add A product, (it is selected by the system) and if the quantity is more than 2, I want to make a discount on this product.

You should try this-

add_action( 'woocommerce_cart_calculate_fees','woocommerce_add_discount',10, 1 );
function woocommerce_add_discount() {
    global $woocommerce;

    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    $cart_qty = count($woocommerce->cart->get_cart());

    if($cart_qty > 2)
    {
        $percentage     = 0.5;

        $cart_subtotal  = $woocommerce->cart->get_subtotal() ?: 0;

        //$cart_total     = $woocommerce->cart->cart_contents_total;
        //$shipping_total = $woocommerce->cart->get_shipping_total() ?: 0;
        //$tax_total      = $woocommerce->cart->get_taxes_total() ?: 0;
        //$grand_total    = $cart_total + $shipping_total + $tax_total;

        // Calculate the amount to reduce
        $discount = $cart_subtotal * $percentage;
        $woocommerce->cart->add_fee( 'Discount 50%', -$discount, true, '' );
    }
}

You can update/modify condition accordingly.

hello thanks for the reply. but there is cart total i need to prepare order list table update. — Fatih Toprak, Sep 22 '21 at 10:02

score 0 · Accepted Answer · answered Sep 23 '21 at 20:41

        /**
         * Add filter for order list 
         *
         * @param [int] $product_subtotal
         * @param [object] $product
         * @param [int] $quantity
         * @param [array] $cart
         * @return void
         */
        public function filterWoocommerceCartProductSubtotal($product_subtotal, $product, $quantity, $cart) : string
        {
            $appliedCoupons  = $cart ? $cart->get_applied_coupons() : null;
            $cartCount = $cart ? count($cart->get_cart()) : 0;
            $cartItems = $cart->get_cart();
            $lastItemInCart = last($cartItems);
            $lastItemsProductId = data_get($lastItemInCart, 'product_id', data_get($lastItemInCart, 'product_id'));
            $lastItemsPrice = $lastItemInCart['data']->get_regular_price();
            $lastItemsQuantity = data_get($lastItemInCart, 'quantity');
            $lastItemsKey = data_get($lastItemInCart, 'key');
            
            if( in_array('3al2ode', $appliedCoupons)){  
                if($lastItemsQuantity > 1) {
                    if(@data_get($product,'id') == $lastItemsProductId)
                    {
                        $newSubTotal = 0;
                        $price = $product->get_price();  

                        $newQuantity = $lastItemsQuantity-1; 
                        $quantity = $newQuantity; 
                        $newSubTotal += $price * $quantity;
                
                        return $newSubTotal ? wc_price($newSubTotal) : $product_subtotal; 
                    }
                } 
                
            }  
            return $product_subtotal;
            
        }

The right, filter should be like;

add_filter( 'woocommerce_cart_product_subtotal', [$this,'filterWoocommerceCartProductSubtotal'], 10, 4);

updating product subtotal in cart contents

2 Answers2