Merge pull request DesignPatternsPHP#285 from ko22009/master

State pattern is maintainable

Author: Dominik Liebler

Behavioral/State/ContextOrder.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+class ContextOrder extends StateOrder
+{
+    public function getState():StateOrder
+    {
+        return static::$state;
+    }
+
+    public function setState(StateOrder $state)
+    {
+        static::$state = $state;
+    }
+
+    public function done()
+    {
+        static::$state->done();
+    }
+
+    public function getStatus(): string
+    {
+        return static::$state->getStatus();
+    }
+}

Behavioral/State/CreateOrder.php

@@ -2,34 +2,15 @@
 
 namespace DesignPatterns\Behavioral\State;
 
-class CreateOrder implements Order
+class CreateOrder extends StateOrder
 {
-    /**
-     * @var array
-     */
-    private $details;
-
-    /**
-     * @param array $details
-     */
-    public function __construct(array $details)
-    {
-        $this->details = $details;
-    }
-
-    public function shipOrder()
-    {
-        $this->details['status'] = 'shipping';
-        $this->details['updatedTime'] = time();
-    }
-
-    public function completeOrder()
+    public function __construct()
     {
-        throw new \Exception('Can not complete the order which status is created');
+        $this->setStatus('created');
     }
 
-    public function getStatus(): string
+    protected function done()
     {
-        return $this->details['status'];
+        static::$state = new ShippingOrder();
     }
 }

Behavioral/State/Order.php

@@ -20,15 +20,15 @@ Code
 
 You can also find this code on `GitHub`_
 
-OrderRepository.php
+ContextOrder.php
 
-.. literalinclude:: OrderRepository.php
+.. literalinclude:: ContextOrder.php
    :language: php
    :linenos:
 
-Order.php
+StateOrder.php
 
-.. literalinclude:: Order.php
+.. literalinclude:: StateOrder.php
    :language: php
    :linenos:
 

Behavioral/State/OrderRepository.php

@@ -2,34 +2,15 @@
 
 namespace DesignPatterns\Behavioral\State;
 
-class ShippingOrder implements Order
+class ShippingOrder extends StateOrder
 {
-    /**
-     * @var array
-     */
-    private $details;
-
-    /**
-     * @param array $details
-     */
-    public function __construct(array $details)
-    {
-        $this->details = $details;
-    }
-
-    public function shipOrder()
-    {
-        throw new \Exception('Can not ship the order which status is shipping!');
-    }
-
-    public function completeOrder()
+    public function __construct()
     {
-        $this->details['status'] = 'completed';
-        $this->details['updatedTime'] = time();
+        $this->setStatus('shipping');
     }
 
-    public function getStatus(): string
+    protected function done()
     {
-        return $this->details['status'];
+        $this->setStatus('completed');
     }
 }

Behavioral/State/README.rst

@@ -0,0 +1,32 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+abstract class StateOrder
+{
+    /**
+     * @var array
+     */
+    private $details;
+
+    /**
+     * @var StateOrder $state
+     */
+    protected static $state;
+
+    /**
+     * @return mixed
+     */
+    abstract protected function done();
+
+    protected function setStatus(string $status)
+    {
+        $this->details['status'] = $status;
+        $this->details['updatedTime'] = time();
+    }
+
+    protected function getStatus(): string
+    {
+        return $this->details['status'];
+    }
+}

Behavioral/State/ShippingOrder.php

@@ -2,33 +2,30 @@
 
 namespace DesignPatterns\Behavioral\State\Tests;
 
-use DesignPatterns\Behavioral\State\OrderRepository;
+use DesignPatterns\Behavioral\State\ContextOrder;
+use DesignPatterns\Behavioral\State\CreateOrder;
 use PHPUnit\Framework\TestCase;
 
 class StateTest extends TestCase
 {
     public function testCanShipCreatedOrder()
     {
-        $order = (new OrderRepository())->findById(1);
-        $order->shipOrder();
+        $order = new CreateOrder();
+        $contextOrder = new ContextOrder();
+        $contextOrder->setState($order);
+        $contextOrder->done();
 
-        $this->assertEquals('shipping', $order->getStatus());
+        $this->assertEquals('shipping', $contextOrder->getStatus());
     }
 
     public function testCanCompleteShippedOrder()
     {
-        $order = (new OrderRepository())->findById(2);
-        $order->completeOrder();
+        $order = new CreateOrder();
+        $contextOrder = new ContextOrder();
+        $contextOrder->setState($order);
+        $contextOrder->done();
+        $contextOrder->done();
 
-        $this->assertEquals('completed', $order->getStatus());
-    }
-
-    /**
-     * @expectedException \Exception
-     */
-    public function testThrowsExceptionWhenTryingToCompleteCreatedOrder()
-    {
-        $order = (new OrderRepository())->findById(1);
-        $order->completeOrder();
+        $this->assertEquals('completed', $contextOrder->getStatus());
     }
 }