refactored State pattern example

Author: Dominik Liebler

Behavioral/State/ContextOrder.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+class OrderContext
+{
+    /**
+     * @var State
+     */
+    private $state;
+
+    public static function create(): OrderContext
+    {
+        $order = new self();
+        $order->state = new StateCreated();
+
+        return $order;
+    }
+
+    public function setState(State $state)
+    {
+        $this->state = $state;
+    }
+
+    public function proceedToNext()
+    {
+        $this->state->proceedToNext($this);
+    }
+
+    public function toString()
+    {
+        return $this->state->toString();
+    }
+}

Behavioral/State/CreateOrder.php

@@ -20,27 +20,33 @@ Code
 
 You can also find this code on `GitHub`_
 
-ContextOrder.php
+OrderContext.php
 
-.. literalinclude:: ContextOrder.php
+.. literalinclude:: OrderContext.php
    :language: php
    :linenos:
 
-StateOrder.php
+State.php
 
-.. literalinclude:: StateOrder.php
+.. literalinclude:: State.php
    :language: php
    :linenos:
 
-ShippingOrder.php
+StateCreated.php
 
-.. literalinclude:: ShippingOrder.php
+.. literalinclude:: StateCreated.php
    :language: php
    :linenos:
 
-CreateOrder.php
+StateShipped.php
 
-.. literalinclude:: CreateOrder.php
+.. literalinclude:: StateShipped.php
+   :language: php
+   :linenos:
+
+StateDone.php
+
+.. literalinclude:: StateDone.php
    :language: php
    :linenos:
 

Behavioral/State/OrderContext.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+interface State
+{
+    public function proceedToNext(OrderContext $context);
+
+    public function toString(): string;
+}

Behavioral/State/README.rst

@@ -0,0 +1,16 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+class StateCreated implements State
+{
+    public function proceedToNext(OrderContext $context)
+    {
+        $context->setState(new StateShipped());
+    }
+
+    public function toString(): string
+    {
+        return 'created';
+    }
+}

Behavioral/State/ShippingOrder.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+class StateDone implements State
+{
+    public function proceedToNext(OrderContext $context)
+    {
+        // there is nothing more to do
+    }
+
+    public function toString(): string
+    {
+        return 'done';
+    }
+}

Behavioral/State/State.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+class StateShipped implements State
+{
+    public function proceedToNext(OrderContext $context)
+    {
+        $context->setState(new StateDone());
+    }
+
+    public function toString(): string
+    {
+        return 'shipped';
+    }
+}