从类中创建类的新实例它在PHP中扩展

Question

我正在编写一个PHP中的大脚本，它需要从未来用户创建的扩展中安全。 我想通了，要创造这样的权限类检查，以一些核心变量等扩展访问

这里是启动类：

class SystemStartup 
{ 
    private function startClass () { 
     require (dirname(__FILE__) . '/sys.run.php'); 
     //starting SystemRun with something like core security token 
     new SystemRun (hash ('sha256' , $_SERVER['HTTP_USER_AGENT'] . $_SERVER['REMOTE_ADDR'] . microtime (TRUE))); 
    } 
    function __construct () { 
     //here i have some security stuff like checking class not already running 
     $this -> startClass (); 
    } 
    function __destruct () { 
     //wywolane na samym koncu 
    } 

}; 

SystemRun类：

class SystemRun 
{ 
    private  $SystemToken; 

    //static because i want to be callable from other classes extending SystemRun 
    protected static $SystemUrlControl; 

    private function startClass () { 

     //before more code 

     //loading file with child class 
     require (dirname(__FILE__) . '/urlcontrol.php'); 
     //starting it with security token 
     echo $this -> SystemToken; //just for check 
     self :: $SystemUrlControl = new SystemUrlControl ($this -> SystemToken); 

     //more more more code (its main class) 
    } 
    protected function validateToken ($SystemToken) { 
     echo $this -> SystemToken; //just for check 
     //this should check tokens are the same 
     if ($this -> SystemToken == $SystemToken) return TRUE; 
     return FALSE; 
    } 
    function __construct ($SystemToken) { 
     //saving token for next classes 
     $this -> SystemToken = $SystemToken; 
     $this -> startClass (); 
    } 
}; 

现在SystemUrlControl与扩展SystemRun

class SystemUrlControl extends SystemRun 
{ 
    private   $SystemToken; 

    //functions 

    //more functions 

    //more more more 

    function __construct ($SystemToken) { 
     if (!parent :: validateToken ($SystemToken)) echo 'somebody else called me!'; 
     $this -> SystemToken = $SystemToken; 
    } 
}; 

问题是从SystemUrlControl调用validateToken返回FALSE - SystemRun将它自己的SystemToken视为NULL。

输出（从回声）是：

> 5b6a09d8f03dd7e6229a5... (valid token) (here NULL value) somebody else called me! 

Answer 1

在你validateToken方法你有这个。

$this -> $SystemToken 

应该

$this -> SystemToken