first commit

wp-content/plugins/unyson/framework/helpers/class-fw-access-key.php

@@ -0,0 +1,43 @@
+<?php if (!defined('FW')) die('Forbidden');
+
+/**
+ * Used in public callbacks to allow call only from known caller
+ * 
+ * For e.g. Inside some class is created an instance of FW_Access_Key with unique key 'whatever',
+ * so nobody else can create another instance with same key, only that class owns that unique key.
+ * Some public callback (function or method) that wants to allow to be called only by that class,
+ * sets an requirement that some parameter should be an instance on FW_Access_Key and its key should be 'whatever'
+ * 
+ * function my_function(FW_Access_Key $key, $another_parameter) {
+ *  if ($key->get_key() !== 'whatever') {
+ *      trigger_error('Call denied', E_USER_ERROR);
+ *  }
+ * 
+ *  //...
+ * }
+ */
+final class FW_Access_Key
+{
+	private static $created_keys = array();
+
+	private $key;
+	
+	final public function get_key()
+	{
+		return $this->key;
+	}
+
+	/**
+	 * @param string $unique_key unique
+	 */
+	final public function __construct($unique_key)
+	{
+		if (isset(self::$created_keys[$unique_key])) {
+			trigger_error('Key "'. $unique_key .'" already defined', E_USER_ERROR);
+		}
+		
+		self::$created_keys[$unique_key] = true;
+		
+		$this->key = $unique_key;
+	}
+}