Question

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();
?>

Answer 1

You need to use call_user_func to do this:

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

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

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!");
     }
 }

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

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

And class methods:

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

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