单个实例的PHP覆盖功能 [英] PHP override function of a single instance

问题描述

在 javascript 中，我知道可以简单地覆盖单个实例的类方法，但我不太确定这是如何在 PHP 中管理的.这是我的第一个想法:

In javascript i know it is possible to simply override a class-method of a single instance but I am not quite sure how this is managable in PHP. Here is my first idea:

class Test {
    public $var = "placeholder";
    public function testFunc() {
        echo "test";
    }
}

$a = new Test();

$a->testFunc = function() {
    $this->var = "overridden";
};

我的第二次尝试是匿名函数调用，不幸的是它杀死了对象作用域...

My second attempt was with anonymous function calls which unfortunately kills the object scope...

class Test {
    public $var = "placeholder";
    public $testFunc = null;
    public function callAnonymTestFunc() {
        $this->testFunc();
    }
}

$a = new Test();

$a->testFunc = function() {
    //here the object scope is gone... $this->var is not recognized anymore
    $this->var = "overridden";
};

$a->callAnonymTestFunc();

推荐答案

为了完全理解你在这里想要实现的目标，你应该首先知道你想要的 PHP 版本，PHP 7 比以前的任何版本都更适合 OOP 方法版本.

In order to fully understand what you are trying to achieve here, your desired PHP version should be known first, PHP 7 is more ideal for OOP approaches than any previous version.

如果你的匿名函数的绑定有问题，你可以绑定a的作用域函数 PHP >= 5.4 到一个实例，例如

If the binding of your anonymous function is the problem, you can bind the scope of a function as of PHP >= 5.4 to an instance, e.g.

$a->testFunc = Closure::bind(function() {
    // here the object scope was gone...
    $this->var = "overridden";
}, $a);

从 PHP >= 7 开始，您可以在创建的闭包上立即调用 bindTo

As of PHP >= 7 you can call bindTo immediately on the created Closure

$a->testFunc = (function() {
    // here the object scope was gone...
    $this->var = "overridden";
})->bindTo($a);

尽管您尝试实现的方法超出了我的想象.也许你应该试着澄清你的目标，我会找出所有可能的解决方案.

Though your approach of what you are trying to achieve is beyond my imagination. Maybe you should try to clarify your goal and I'll workout all possible solutions.

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