Added custom API exception class.

src/engine/Api/V1/Exception.php

@@ -0,0 +1,54 @@
+<?php 
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Open Source Web Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) 2013 - 2016, Alex Tselegidis
+ * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        http://easyappointments.org
+ * @since       v1.2.0
+ * ---------------------------------------------------------------------------- */
+
+namespace EA\Engine\Api\V1; 
+
+/**
+ * API v1 Exception Class
+ *
+ * This exception variation will hold the information needed for exception handling in the API. 
+ */
+class Exception extends \Exception {
+    /**
+     * Header Description 
+     *
+     * e.g. 'Unauthorized'
+     * 
+     * @var string
+     */
+    protected $header;
+
+    /**
+     * Class Constructor 
+     *
+     * @link http://php.net/manual/en/class.exception.php
+     * 
+     * @param string $message 
+     * @param int $code
+     * @param string $header 
+     * @param \Exception|null $previous 
+     */
+    public function __construct($message = null, $code = 500, $header = '', \Exception $previous = null) {
+        parent::__construct($message, $code, $previous);
+        $this->header = $header;
+    }
+
+    /**
+     * Get the header string. 
+     * 
+     * @return string
+     */
+    public function getHeader() {
+        return $this->header;
+    }
+}