From 6c786e6a1739feeff921b9e7d113b0cd5c359a70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kucha=C5=99?= <honza.kuchar@grifart.cz>
Date: Sun, 21 Feb 2016 12:21:53 +0100
Subject: [PATCH] Basket (green): Add ability to restore basket from historical
events
---
app/AggregateHistory.php | 29 ++++++++++++++++
app/aggreagates/AbstractAggregate.php | 35 +++++++++++++++++++
app/aggreagates/Basket.php | 50 ++++++++++++++++++++++-----
3 files changed, 106 insertions(+), 8 deletions(-)
create mode 100644 app/AggregateHistory.php
create mode 100644 app/aggreagates/AbstractAggregate.php
diff --git a/app/AggregateHistory.php b/app/AggregateHistory.php
new file mode 100644
index 0000000..11c3416
--- /dev/null
+++ b/app/AggregateHistory.php
@@ -0,0 +1,29 @@
+<?php
+
+/**
+ * Collection of domain events
+ */
+class AggregateHistory extends ArrayObject {
+
+ private $aggregateId;
+
+ public function __construct($aggregateId, DomainEvents $domainEvents)
+ {
+ $this->aggregateId = $aggregateId;
+
+ // type check for IDomainEvent[]
+ array_filter((array) $domainEvents, function(IDomainEvent $domainEvent) {});
+
+ parent::__construct((array) $domainEvents);
+ }
+
+ /**
+ * @return array|null|object
+ */
+ public function getAggregateId()
+ {
+ return $this->aggregateId;
+ }
+
+
+}
\ No newline at end of file
diff --git a/app/aggreagates/AbstractAggregate.php b/app/aggreagates/AbstractAggregate.php
new file mode 100644
index 0000000..5ed490d
--- /dev/null
+++ b/app/aggreagates/AbstractAggregate.php
@@ -0,0 +1,35 @@
+<?php
+
+abstract class AbstractAggregate
+{
+
+ /**
+ * @param \IDomainEvent $domainEvent
+ * @return string
+ */
+ private function getApplyMethodForDomainEvent(IDomainEvent $domainEvent)
+ {
+ return "apply" . get_class($domainEvent);
+ }
+
+ /**
+ * Apply domain event if this aggregate accepts this event
+ * @param \IDomainEvent $domainEvent
+ * @internal
+ */
+ public function applyIfAccepts(IDomainEvent $domainEvent) {
+ if(method_exists($this, $this->getApplyMethodForDomainEvent($domainEvent))) {
+ $this->apply($domainEvent);
+ }
+ }
+
+ /**
+ * Apply domain event; if objects does not accepts this event -> fail
+ * @param \IDomainEvent $domainEvent
+ */
+ public function apply(IDomainEvent $domainEvent) {
+ $method = $this->getApplyMethodForDomainEvent($domainEvent);
+ $this->$method($domainEvent);
+ }
+
+}
\ No newline at end of file
diff --git a/app/aggreagates/Basket.php b/app/aggreagates/Basket.php
index 2886688..2fe9830 100644
--- a/app/aggreagates/Basket.php
+++ b/app/aggreagates/Basket.php
@@ -1,6 +1,6 @@
<?php
-final class Basket implements RecordsEvents
+final class Basket extends AbstractAggregate implements RecordsEvents
{
/** @var BasketId $basketId */
@@ -29,6 +29,17 @@ final class Basket implements RecordsEvents
return $basket;
}
+ public static function reconstituteFrom(AggregateHistory $aggregateHistory)
+ {
+ $basketId = $aggregateHistory->getAggregateId();
+ $basket = new static($basketId);
+
+ foreach($aggregateHistory as $event) {
+ $basket->apply($event);
+ }
+ return $basket;
+ }
+
// ------------- public interface --------------
public function addProduct(ProductId $productId, $name)
{
@@ -40,11 +51,7 @@ final class Basket implements RecordsEvents
new ProductWasAddedToBasket($this->basketId, $productId, $name)
);
- // Update internal tracked state
- if(!$this->isProductInBasket($productId)) {
- $this->itemsCountById[(string)$productId] = 0;
- }
- $this->itemsCountById[(string)$productId]++;
+ // Internal state NOT changed directly @see apply() method
}
public function removeProduct(ProductId $productId)
@@ -59,8 +66,34 @@ final class Basket implements RecordsEvents
new ProductWasRemovedFromBasket($this->basketId, $productId)
);
- // Update internal tracked state
- $this->itemsCountById[(string)$productId]--;
+ // Internal state NOT changed directly @see apply() method
+ }
+
+ // --------- object state transitions based on incoming events ---------
+
+ /**
+ * @param \ProductWasAddedToBasket $productWasAddedToBasket
+ */
+ public function applyProductWasAddedToBasket(ProductWasAddedToBasket $productWasAddedToBasket)
+ {
+ $productId = $productWasAddedToBasket->getProductId();
+ if (!$this->isProductInBasket($productId)) {
+ $this->itemsCountById[(string) $productId] = 0;
+ }
+ $this->itemsCountById[(string) $productId]++;
+ }
+
+ /**
+ * @param \ProductWasRemovedFromBasket $productWasRemovedFromBasket
+ */
+ public function applyProductWasRemovedFromBasket(ProductWasRemovedFromBasket $productWasRemovedFromBasket)
+ {
+ $productId = $productWasRemovedFromBasket->getProductId();
+ $this->itemsCountById[(string) $productId]--;
+ }
+
+ public function applyBasketWasPickedUp()
+ {
}
// ------------ guarding helpers --------------------
@@ -93,6 +126,7 @@ final class Basket implements RecordsEvents
private function recordThat(IDomainEvent $domainEvent)
{
$this->recordedEvents[] = $domainEvent;
+ $this->apply($domainEvent);
}
}
\ No newline at end of file
--
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