Add new validator to check if input is instance of a certain class

Change-Id: I6365cf9a6652ca42a1f6897002e5abe455ed4f44

library/Zend/Validator/IsInstanceOf.php

@@ -0,0 +1,112 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link      http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   http://framework.zend.com/license/new-bsd New BSD License
+ * @package   Zend_Validator
+ */
+
+namespace Zend\Validator;
+
+use Traversable;
+use Zend\Stdlib\ArrayUtils;
+use Zend\Validator\AbstractValidator;
+
+class IsInstanceOf extends AbstractValidator
+{
+
+    const NOT_INSTANCE_OF = 'notInstanceOf';
+
+    /**
+     * Validation failure message template definitions
+     *
+     * @var array
+     */
+    protected $messageTemplates = array(
+        self::NOT_INSTANCE_OF => "The input is not an instance of '%className%'"
+    );
+
+    /**
+     * Additional variables available for validation failure messages
+     *
+     * @var array
+     */
+    protected $messageVariables = array(
+        'className' => 'className'
+    );
+
+    /**
+     * Class name
+     *
+     * @var string
+     */
+    protected $className;
+
+    /**
+     * Sets validator options
+     *
+     * @param  array|Traversable $options
+     * @throws Exception\InvalidArgumentException
+     */
+    public function __construct($options = null)
+    {
+        if ($options instanceof Traversable) {
+            $options = ArrayUtils::iteratorToArray($options);
+        }
+        if (!is_array($options)) {
+            $options = func_get_args();
+
+            $tmpOptions = array();
+            $tmpOptions['classname'] = array_shift($options);
+
+            $options = $tmpOptions;
+        }
+
+        if (!array_key_exists('className', $options)) {
+            throw new Exception\InvalidArgumentException("Missing option 'className'");
+        }
+
+        $this->setClassName($options['className']);
+
+        parent::__construct($options);
+    }
+
+    /**
+     * Get class name
+     *
+     * @return string
+     */
+    public function getClassName()
+    {
+        return $this->className;
+    }
+
+    /**
+     * Set class name
+     *
+     * @param  string $className
+     * @return self
+     */
+    public function setClassName($className)
+    {
+        $this->className = $className;
+        return $this;
+    }
+
+    /**
+     * Returns true if $value is instance of $this->className
+     *
+     * @param  mixed $value
+     * @return boolean
+     */
+    public function isValid($value)
+    {
+        if($value instanceof $this->className) {
+            return true;
+        }
+        $this->error(self::NOT_INSTANCE_OF);
+        return false;
+    }
+}