refactored State pattern example

Behavioral/State/OrderContext.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();
+    }
+}