Woocommerce - 发送自定义 通过 ajax 发送自定义设置的产品价格到购物车

Question

I have set a custom discounted product price in a variable (i just want to show the discount for an order bump) and added a checkbox which sends an ajax request when it´s checked so the discounted product gets added to the cart.

The product gets added to the cart fine, but it doesn´t have the discounted price.

Any ideas what i´m doing wrong here?

The checkbox with the data-attributes:

<input type="checkbox" class="add-to-cart-checkbox" data-product-id="' . $upsell_product_id . '" data-product-price="' . $discounted_price . '" />

The Ajax Script for adding the product with the discounted price:

$('.add-to-cart-checkbox').click(function() {
                var product_id = $(this).data('product-id');
                var product_price = $(this).data('product-price');

                if (this.checked) {
                    $.post(woocommerce_params.ajax_url, {
                        'action': 'woocommerce_add_to_cart',
                        'product_id': product_id,
                        'product_price': product_price,
                    }, function(response) {
                        console.log(response);
                    });
                }
            });

Answer 1

This problem is interesting and not easy to solve. The problem is that the cart item is recalculated all the time and price will get back to original after you set it. Here is one approach you can use to trick the WooCommerce.

First, we check if there is product_price in $_POST variable when we add the product into the cart. If the product_price is there we store the special price into the $wc_session so we can use it later, for example when other product is added and cart recalculated.

add_action( 'woocommerce_add_to_cart', 'store_special_price_to_session', 10, 3 );
function store_special_price_to_session( $cart_item_key, $product_id, $quantity ) {
    if( isset( $_POST['product_price'] )) {
        // Sanitize the product price
        $product_price = wp_kses( $_POST['product_price'], array() );
        // Get the WC_Session instance
        $wc_session = WC()->session;
        $wc_session->set( 'special_price_'.$product_id, $product_price );
    }
}

Then, in the second snippet, we change the price of the item every time when the cart is recalculated. We pull the special price we stored in the session and replace the original cart item price. If we don't do this, the price will return to the original product price.

add_action( 'woocommerce_before_calculate_totals', 'apply_special_price_to_cart_item', 10, 1 );
function apply_special_price_to_cart_item( $cart_object ) {
    // Get the WC_Session instance
    $wc_session = WC()->session;

    foreach ( $cart_object->get_cart() as $cart_item ) {
        // Get the special price from the session data
        $special_price = $wc_session->get( 'special_price_'.$cart_item['product_id'] );

        // Sanitize the special price
        $special_price = wp_kses( $special_price, array() );

        if( ! empty( $special_price ) ) {
            $cart_item['data']->set_price( $special_price );
        }
    }
}

Important note : This code is a proof of concept, it should do the work you need but someone can easily change the javascript call and set a price of any product to $0 (for current user only). It would be better to use the special price stored on the server instead of trusting something coming from the javascript request. Also, it's highly recommended to use wp_verify_nonce to make the request more secured.