How to check if a order has a shipment in Magento?

Question

I need to check if an order has already some shipment set. The only data I can use is the increment id of the order. I'm getting an instance of a model order, but I don't see a way I can get a shipment instance.

I'm using this code:

$order = Mage::getModel('sales/order')
    ->loadByIncrementId($order_increment_id);

But how can I get a shipment instance? I know that I can call Mage::getModel('sales/order_shipment')->loadByIncrementId($shipment_increment_id) but how do I get the shipment increment id?

Answer 1

Just to make it complete Mage_Sales_Model_Order has public method:
hasShipments()
which returns number of shipments and internally uses mentioned getShipmentsCollection().

Answer 2

Assume that the person who wrote this might have also needed to do what you need to do. Generally, when Magento objects have a one to many relationship you can find a method to load the many on the one.

You've got a class alias sales/order.

This corresponds to Mage_Sales_Model_Order (in a stock installation).

You can find this class at app/code/core/Mage/Sales/Model/Order.php.

If you examine this class, there are 7 methods with the word "ship" in them

function canShip
function setShippingAddress
function getShippingAddress
function getShip
function getShipmentsCollection
function hasShip
function prepareShip

Of those 7, only the semantics of getShipmentsCollection indicate a method for grabbing an order's shipments. So try

foreach($order->getShipmentsCollection() as $shipment)
{
    var_dump(get_class($shipment));
    //var_dump($shipment->getData());
}

Or take a look at the source for getShipmentsCollection

public function getShipmentsCollection()
{
    if (empty($this->_shipments)) {
        if ($this->getId()) {
            $this->_shipments = Mage::getResourceModel('sales/order_shipment_collection')
                ->setOrderFilter($this)
                ->load();
        } else {
            return false;
        }
    }
    return $this->_shipments;
}