added proxy pattern

Proxy/Proxy.php

@@ -0,0 +1,94 @@
+<?php
+
+namespace DesignPatterns;
+
+/**
+ * Proxy pattern
+ *
+ * Purpose:
+ * to interface to anything that is expensive or impossible to duplicate
+ *
+ * Examples:
+ * - Doctrine2 uses proxies to implement framework magic (e.g. Lazy initialization) in them, while the user still works
+ *   with his own entity classes and will never use nor touch the proxies
+ *
+ */
+class Record
+{
+    protected $_data;
+
+    public function __construct($data = null)
+    {
+        $this->_data = $data;
+    }
+
+    /**
+     * magic setter
+     *
+     * @param string $name
+     * @param mixed $value
+     * @return void
+     */
+    public function __set($name, $value)
+    {
+        $this->_data[(string) $name] = $value;
+    }
+
+    /**
+     * magic getter
+     *
+     * @param string $name
+     * @return mixed|null
+     */
+    public function __get($name)
+    {
+        if (array_key_exists($name, $this->_data)) {
+            return $this->_data[(string) $name];
+        } else {
+            return null;
+        }
+    }
+}
+
+class RecordProxy extends Record
+{
+    /**
+     * @var bool
+     */
+    protected $_isDirrty = false;
+
+    /**
+     * @var bool
+     */
+    protected $_isInitialized = false;
+
+    /**
+     * @param array
+     */
+    public function __construct($data)
+    {
+        parent::__construct($data);
+
+        // when the record has data, mark it as initialized
+        // since Record will hold our business logic, we don't want to
+        // implement this behaviour there, but instead in a new proxy class
+        // that extends the Record class
+        if (null !== $data) {
+            $this->_isInitialized = true;
+            $this->_isDirrty = true;
+        }
+    }
+
+    /**
+     * magic setter
+     *
+     * @param string $name
+     * @param mixed $value
+     * @return void
+     */
+    public function __set($name, $value)
+    {
+        $this->_isDirrty = true;
+        parent::__set($name, $value);
+    }
+}