PHP:如何在类层次结构中调用所有同名方法?

时间:2012-05-12 05:26:29

标签: php inheritance

我有一个类层次结构,如下所示:

class Alpha {
    public function initialize() {
        $class = get_class($this);
        $family = array( $class );
        while( ($class = get_parent_class($class)) !== false ) {
            $family[] = $class;
        }
        $family = array_reverse($family);
        foreach($family as $className) {
            // call $className's start (instance) method
        }
    }

    public function start() {
        echo "calling start from Alpha\n";
    }
}

class Beta extends Alpha {
    public function start() {
        echo "calling start from Beta\n";
    }
}

class Charlie extends Beta {
    public function start() {
        echo "calling start from Charlie\n";
    }
}

$c = new Charlie();
$c->initialize();

Alpha的initialize方法应该调用派生类的start方法以及所有派生类的祖先类的start方法,一直到Alpha的start方法。代码应该产生以下输出:

calling start from Alpha
calling start from Beta
calling start from Charlie

但是,我似乎无法弄清楚如何调用$ className变量指定的特定祖先类的实例方法。

我使用过call_user_func(array($className, 'start'))但这会导致start方法被视为静态函数。有什么想法吗?

2 个答案:

答案 0 :(得分:2)

class Alpha {
    public function initialize() {
        // ... call all 'start' methods in class hierarchy starting with highest level     class (Alpha's start method) and ending with lowest derived class
    }

    public function start() {
        echo "calling start from Alpha\n";
    }
}

class Beta extends Alpha {
    public function start() {
        echo "calling start from Beta\n";
        parent::start();
    }
}

class Charlie extends Beta {
    public function start() {
        echo "calling start from Charlie\n";
        parent::start();
    }

    public function initialize() {
        $this->start();
    }
}

$c = new Charlie();
$c->initialize();

答案 1 :(得分:2)

在类函数调用中,如Classname :: start应该调用Classname的函数start not static call

class Alpha {

    public $myvar = 0;

    public function initialize() {

        $class = get_class($this);
        $family = array( $class );
        while( ($class = get_parent_class($class)) !== false ) {
            $family[] = $class;
            $this->myvar ++;
        }
        $family = array_reverse($family);
        foreach($family as $className) {
            // call $className's start method
            eval("{$className}::start();");
        }
    }

    public function start() {
        echo "{$this->myvar} calling start from Alpha\n";
    }
}

class Beta extends Alpha {
    public function start() {
        echo "{$this->myvar} calling start from Beta\n";
    }
}

class Charlie extends Beta {
    public function start() {
        echo "{$this->myvar} calling start from Charlie\n";
    }
}

$c = new Charlie();
$c->initialize();