private function whenProductWasAddedToBasket(ProductWasAddedToBasket $event)
{
// Remember that all of this code used to be in `addProduct()`
$productId = $event->getProductId();
if (!$this->productIsInBasket($productId)) {
$this->products[(string) $productId] = 0;
}
++$this->products[(string) $productId];
++$this->productCount;
}
// ... and in the name. We'll get to that.
public function getProductName()
{
return $this->productName;
}
}
// Notice that Domain Events are **immutable**. Once they have been initialized, there's no way to change them, there
// are No setters. That makes perfect sense: History can't be altered!
final class ProductWasRemovedFromBasket implements DomainEvent
{
private $basketId;
private $productId;
public function __construct(BasketId $basketId, ProductId $productId)
{
$this->basketId = $basketId;
$this->productId = $productId;
}
public function getAggregateId()
{
return $this->basketId;
}
public function getProductId()
{
return $this->productId;
}
}
// Let's test one of our Domain Events. Did we mention this documentation doubles as test suite?
$event = new ProductWasAddedToBasket(new BasketId('BAS1'), new ProductId('PRO1'), "The Princess Bride");
it('should equal another instance with the same value', $event->getAggregateId()->equals(new BasketId('BAS1')));
it("should expose a ProductId", $event->getProductId()->equals(new ProductId('PRO1')));
it("should expose a productName", $event->getProductName() == "The Princess Bride");