PHP中在子构造函数之前调用父构造函数 [英] Call parent constructor before child constructor in PHP

问题描述

我想知道是否可以在使用 PHP 继承的孩子的 __construct() 之前调用父母的 __construct().

I was wondering if its possible to call the parents __construct(), before the child's __construct() with inheritance in PHP.

示例:

class Tag {
     __construct() {
         // Called first.
     }
}

class Form extends Tag {
     __construct() {
         // Called second.
     }
} 

new Form();

理想情况下，我可以在它们之间做一些事情.如果这是不可能的，是否有替代方法可以让我这样做?

Ideally, I would be able to do something in between them. If this is not possible, is there an alternative, which would allow me to do this?

我想这样做的原因是为了能够加载一堆特定于在调用 __construct() 时表单可以使用的标签的默认设置.

The reason I want to do this is to be able to load a bunch of default settings specific to the Tag that Form can use when __construct() is called.

抱歉忘了添加这个..我宁愿不从子类调用父类.这仅仅是因为当您将其作为参数传递时，它会向孩子公开一些私有数据(对于父级)

这就是我想要做的:

$tag = new Tag($privateInfo, $publicInfo);
$tag->extend(new Form()); // Ideal function, prob doesn't work with inheritance.

Tag.php

class Tag {
     private $privateInfo;
     public $publicInfo;
     __construct($private, $public) {
         $this->privateInfo = $private;
         $this->publicInfo = $public;
     }
} 

Form.php

class Form extends Tag {

     __construct() {
         echo $this->publicInfo;
     }
} 

有意义吗?

谢谢！马特·穆勒

推荐答案

只需在孩子中调用 parent::__construct 即可.

Just call parent::__construct in the child.

class Form extends Tag
{
    function __construct()
    {
        parent::__construct();
        // Called second.
    }
}

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