通过 URL 添加到购物车上的 WooCommerce 自定义购物车商品价格

Question

I have a simple product with a default price value of 100.

As you choose a product it must go directly to checkout, this I handle simply like this:

/checkout/?add-to-cart=78

However, it must be possible to override the price of this product, as it's a voulenteer donation amount.

I am trying this:

/checkout/?add-to-cart=78&donation=200

And in my functions.php I have:

add_action( 'woocommerce_before_calculate_totals', 'add_custom_price', 10, 1);
function add_custom_price( $cart ) {

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

    // Avoiding hook repetition (when using price calculations for example)
    if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;



    foreach ( $cart->get_cart() as $cart ) {
        $id = $cart['data']->get_id();

        if ($id === 78 && $_GET['donation']) {
            $price = $_GET['donation'];
        }
        else {
            $price = $cart['data']->get_price();
        }

        $cart['data']->set_price( $price );

    }   
}

When the page is first loaded, it has set the price to 200. However, the JS doing an ajax call after reload to this url:

/?wc-ajax=update_order_review

Resets the price to 100.

How can I stop it from resetting the price?

Answer 1

You need to set the donation as custom cart item data on add-to-cart event, avoiding losing it when checkout get refreshed by ajax.

In the following code, we catch the donation value that we set as custom cart item data, then we add it to the corresponding cart item price.

This happen via the url with something like: /checkout/?add-to-cart=78&donation=200

add_filter( 'woocommerce_add_cart_item_data', 'catch_and_save_submited_donation', 10, 2 );
function catch_and_save_submited_donation( $cart_item_data, $product_id ){
    if( isset($_REQUEST['donation']) ) {
        // Get the WC_Product Object
        $product = wc_get_product( $product_id );

        // Get an set the product active price
        $cart_item_data['active_price'] = (float) $product->get_price();

        // Get the donation amount and set it
        $cart_item_data['donation'] = (float) esc_attr( $_REQUEST['donation'] );
        $cart_item_data['unique_key'] = md5( microtime().rand() ); // Make each item unique
    }
    return $cart_item_data;
}

add_action( 'woocommerce_before_calculate_totals', 'add_donation_to_item_price', 10, 1);
function add_donation_to_item_price( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // Avoiding hook repetition (when using price calculations for example)
    if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;

    // Loop through cart items
    foreach ( $cart->get_cart() as $item ) {
        // Add the donation to the product price
        if ( isset( $item['donation']) && isset( $item['active_price']) ) {
            $item['data']->set_price( $item['active_price'] + $item['donation'] );
        }

    }
}

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