/**
* @param AggregateHistory $aggregateHistory
* @return RecordsEvents
*/
public static function reconstituteFrom(AggregateHistory $aggregateHistory)
{
// `AggregateHistory` is a list of chronological `DomainEvents` for a single Aggregate instance. Let's start by
// fetching its identifier.
$basketId = $aggregateHistory->getAggregateId();
// We instantiate the Basket object. (As you recall, the constructor is private.)
$basket = new BasketV4(new BasketId($basketId));
foreach ($aggregateHistory as $event) {
// As you saw earlier, our Aggregate keeps state, to protect invariants. We need to rebuild this state from
// the events in the `AggregateHistory`. But there's a problem: we can't call methods like `pickUp()`,
// `addProduct()`, and `removeProduct()`, because these would call `recordThat()`. That would cause the
// events to be recorded a second time.
// The trick is to separate the logic that applies events to the state. We'll call a new private method:
$basket->when($event);
}
// Finally we return the newly reconstituted Basket.
return $basket;
}
