php check if method overridden in child class

问题

Is it possible to check whether or not a method has been overridden by a child class in PHP?

<!-- language: lang-php -->

class foo {
    protected $url;
    protected $name;
    protected $id;

    var $baz;

    function __construct($name, $id, $url) {
        $this->name = $name;
        $this->id = $id;
        $this->url = $url;
    }

    function createTable($data) {
        // do default actions
    }
}

Child class:

class bar extends foo {
    public $goo;

    public function createTable($data) {
        // different code here
    }
}

When iterating through an array of objects defined as members of this class, how can I check which of the objects has the new method as opposed to the old one? Does a function such as method_overridden(mixed $object, string $method name) exist?

foreach ($objects as $ob) {
    if (method_overridden($ob, "createTable")) {
        // stuff that should only happen if this method is overridden
    }
    $ob->createTable($dataset);
}

I am aware of the template method pattern, but let's say I want the control of the program to be separate from the class and the methods themselves. I would need a function such as method_overridden to accomplish this.

回答1:

Check if the declaring class matches the class of the object:

$reflector = new \ReflectionMethod($ob, 'createTable');
$isProto = ($reflector->getDeclaringClass()->getName() !== get_class($ob));

PHP Manual links:

ReflectionMethod
ReflectionProperty

回答2:

To get this information, you have to use ReflectionClass. You could try getMethod and check the class name of the method.

$class = new ReflectionClass($this);
$method = $class->getMethod("yourMethod");
if ($method->class == 'classname') {
    //.. do something
}

But keep in mind, that reflection isn't very fast, so be careful with usage.

来源：https://stackoverflow.com/questions/17663178/php-check-if-method-overridden-in-child-class

标签

php

oop

overloading