Convert Custom Field From Quote Item to Order Item

Today, we will learn about the way to convert custom field from quote item to order item in Magento 2, through the below instructions.

Overview of converting a custom feild from quote item to order item in Magento 2

Step 1: Add a di.xml file
Step 2: Identify a code, a plugin
Step 3: Add a class to your module, then identify a function

Step 1: Add a `di.xml` file

In the module app/code/Mageplaza/HelloWorld/etc, please add the di.xml file.

Step 2: Identify a code, a plugin

In the di.xml file, let’s identify a code:

<type name="Magento\Quote\Model\Quote\Item\ToOrderItem">
        <plugin name="HelloWorld_to_order_item" type="Mageplaza\HelloWorld\Model\Plugin\Quote\HelloWorldToOrderItem"/>
</type>

Then, identify a plugin Mageplaza\HelloWorld\Model\Plugin\Quote\HelloWorldToOrderItem” of class “Magento\Quote\Model\Quote\Item\ToOrderItem

Step 3: Add a class to your module, then identify a function

In the module, add the class Mageplaza\HelloWorld\Model\Plugin\Quote\HelloWorldToOrderItem, and identify the function aroundConvert which will convert the custom data from quote item to order item at the same time.

public function aroundConvert(
        \Magento\Quote\Model\Quote\Item\ToOrderItem $subject,
        \Closure $proceed,
        \Magento\Quote\Model\Quote\Item\AbstractItem $item,
        $additional = []
    ) {
        /** @var $orderItem Item */
        $orderItem = $proceed($item, $additional);
$orderItem->setHelloWorldCustomData($item->getHelloWorldCustomData());
        return $orderItem;
    }

You will achieve the result of function convert in class Magento\Quote\Model\Quote\Item\ToOrderITem from the first line of this function $orderItem = $proceed($item, $additional);.
Next, create the value of HelloWorldCustomData for the result of function convert class Magento\Quote\Model\Quote\Item\ToOrderItem.
Then, return an object $orderItem to recover result of the function convert in the class Magento\Quote\Model\Quote\Item\ToOrderItem.