Craft Commerce 2 - get order data for plugin

Question

I want to write a plugin which writes all the order data into a CSV file. Unfortunately the documentation for Commerce 2 isn't quite complete yet so I have difficulties to find out how to do the following with a plugin (so I need to use PHP and not Twig).

1. Get an order by ID.
2. Get ordered items.
3. Get the addresses for the order.

Every help appreciated.

Answer 1

$order = \craft\commerce\elements\Order::find()->id($id)->one();

if($order)
{
  foreach ($order->getLineItems() as $item) {
   // $item->description
   // $item->qty
  }

  $billingAddress = $order->getBillingAddress();
  $shippingAddress = $order->getShippingAddress();
}