从它在 PHP 中扩展的类创建类的新实例

Question

我正在用 PHP 编写一个大脚本，该脚本需要在未来用户创建的扩展中保持安全。 我想创建类似权限类检查对某些核心变量的扩展访问等的东西。

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 扩展了 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（来自回声）是：

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

Answer 1

在您的 validateToken 方法中，您有这个。

$this -> $SystemToken

应该是

$this -> SystemToken