从存储为类成员的字符串中调用类方法 [英] Calling class method from string stored as class member

问题描述

我正在尝试调用存储为$_auto的方法，但是它将不起作用.

I am trying to call a method stored as $_auto, but it will not work.

<?php
    class Index {
        private $_auto;

        public function __construct() {
            $this->_auto = "index";
            $this->_auto();
        }

        public function index() {
            echo "index";
        }
    }

    $index = new Index();
?>

推荐答案

您需要使用 call_user_func 为此:

You need to use call_user_func to do this:

call_user_func(array($this, $this->_auto));

不幸的是，PHP不允许您直接将属性值用作可调用项 callables .

Unfortunately PHP does not allow you to directly use property values as callables.

还有一个技巧可以用来自动调用这样的可调用对象.我不确定我会支持它，但是确实如此.将__call的此实现添加到您的课程中:

There is also a trick you could use to auto-invoke callables like this. I 'm not sure I would endorse it, but here it is. Add this implementation of __call to your class:

 public function __call($name, $args)
 {
     if (isset($this->$name) && is_callable($this->$name)) {
         return call_user_func_array($this->$name, $args);
     }
     else {
         throw new \Exception("No such callable $name!");
     }
 }

这将允许您调用可调用对象，因此可以调用自由函数:

This will allow you to invoke callables, so you can call free functions:

 $this->_auto = 'phpinfo';
 $this->_auto();

和类方法:

 $this->_auto = array($this, 'index');
 $this->_auto();

当然，您可以通过调整__call调用的内容来自定义此行为.

And of course you can customize this behavior by tweaking what __call invokes.

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