run external class connected to contao (e. g. for AJAX calls)

Contao 2.11.x - runExternalClass

<?php

	require('../system/initialize.php');

	class MyClass extends Frontend
	{

		public function __construct()
		{
			// Example: Load user object before calling the parent constructor
			$this->import('FrontendUser', 'User');
			parent::__construct();

		}

		public function run()
		{

			//	run my functions

		}

	}
	/**
	* Instantiate controller
	*/
	$objMyClass = new MyClass();
	//	Run code within MyClass()
	$objMyClass->run();

?>