php – 强迫某人使他的子类实现接口的方法

我想知道如何强制子类来实现给定的接口方法.

假设我有以下课程：

interface Serializable
{
    public function __toString();
}

abstract class Tag // Any HTML or XML tag or whatever like <div>, <p>, <chucknorris>, etc
{
    protected $attributes = array();

    public function __get($memberName)
    {
        return $this->attributes[$member];
    }

    public function __set($memberName, $value)
    {
        $this->attributes[$memberName] = $value;
    }

    public function __construct() { }

    public function __destruct() { }
}

我想强制任何子类“Tag”来实现“Serializable”接口.例如,如果我是一个“Paragraph”类,它会看起来像这样：

class Paragraph extends Tag implements View
{
    public function __toString()
    {
        print '<p';
        foreach($this->attributes as $attribute => $value)
            print ' '.$attribute.'="'.$value.'"';
        print '>';

        // displaying children if any (not handled in this code sample).

        print '</p>';
    }
}

我如何强迫开发人员使他的“Paragraph”类从“Serializable”接口实现方法？

感谢您抽出宝贵时间阅读.

解决方法:

只需要抽象类实现接口：

interface requiredInterface 
{
    public function getName();
}

abstract class BaseClass implements requiredInterface 
{

}

class MyClass extends BaseClass
{

}

运行此代码将导致错误：

Fatal error: Class MyClass contains 1 abstract method and must
therefore be declared abstract or implement the remaining methods
(requiredInterface::getName)

这要求开发人员编写requiredInterface的方法.