The right way to set/get items to/from quote

Question

There are 3 places to store items data in the quote:

• \Magento\Quote\Model\Quote::$_items
• \Magento\Quote\Model\Quote::$_data['items']
• \Magento\Quote\Model\Quote::$_data['items_collection']

\Magento\Quote\Model\Quote

const KEY_ITEMS = 'items';
/**
 * Quote items collection
 *
 * @var \Magento\Eav\Model\Entity\Collection\AbstractCollection
 */
protected $_items;

public function getItems()
{
    return $this->_getData(self::KEY_ITEMS);
}

public function setItems(array $items = null)
{
    return $this->setData(self::KEY_ITEMS, $items);
}

public function getItemsCollection($useCache = true)
{
    if ($this->hasItemsCollection()) {
        return $this->getData('items_collection');
    }
    if (null === $this->_items) {
        $this->_items = $this->_quoteItemCollectionFactory->create();
        $this->extensionAttributesJoinProcessor->process($this->_items);
        $this->_items->setQuote($this);
    }
    return $this->_items;
}

What is the right place to store items data in the quote?

Magento version: 2.1.2

Answer 1

You should probably just use the setItems(array $items) method that you mention above.

You can however run setData('items', $items) but that will assign the same items field as setItems(array $items).

In the same way: getData('items') will return the same thing as getItems();

$_data['items'] probably points to $_items;