在woocommerce_order_item_meta_end钩子中使用get_cart（）方法时出错

Question

I have this code, its function is to add a column in woocommerce order details email template, but when I send an invoice I get this error message saying:

Fatal error: Uncaught Error: Call to a member function get() on null in http:\mysite.com\functions.php on line 1245

when using this code:

add_action( 'woocommerce_order_item_meta_end', 'order_custom_field_in_item_meta_end', 10, 4 );
function order_custom_field_in_item_meta_end( $item_id, $item, $order, $cart_item) {
    global $woocommerce;

    do_action( 'woocommerce_review_order_before_cart_contents' );

    foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
        $_product = apply_filters( 'woocommerce_cart_item_product', $cart_item['data'], $cart_item, $cart_item_key );

        if ( $_product && $_product->exists() && $cart_item['quantity'] > 0 && apply_filters( 'woocommerce_checkout_cart_item_visible', true, $cart_item, $cart_item_key ) ) {
            echo '<td class="td">'.$_product->get_price_html().'</td>';
        }
    }

    do_action( 'woocommerce_review_order_after_cart_contents' );

}

My problem here, is that when I send an invoice or any other email notification from the order it gets an error.

What I am doing wrong and how to solve this?

Thanks

Answer 1

The problem is that the action woocommerce_order_item_meta_end is get triggered only after placing the order. so that the scope of the WC()->cart is not exists inside your code snippet.

You can use $order->get_items() to get order items.

Please modify your code this way to make it work

add_action( 'woocommerce_order_item_meta_end', 'order_custom_field_in_item_meta_end', 10, 4 );
function order_custom_field_in_item_meta_end( $item_id, $item, $order) {
    do_action( 'woocommerce_review_order_before_cart_contents' );

    foreach ( $order->get_items() as $cart_item_key => $cart_item ) {
        // Do something here
    }

    do_action( 'woocommerce_review_order_after_cart_contents' );

}