PHP use __get to call a method?

Question

I've got some PHP cruft that I would like to delegate methods. Sort of a poor-man's mixin.

Basically I would like the following:

<?php

class Apprentice
{
    public function magic() {
        echo 'Abracadabra!';
    }
}

class Sourcerer // I work magic with the source
{
    private $apprentice;

    public function __construct(){
        $this->apprentice = new Apprentice();
    }

    public function __get($key) {
        if (method_exists($this->apprentice, $key)) {
            return $this->apprentice->{$key};
        }
        throw Exception("no magic left");
    }
}

$source = new Sourcerer();
$source->magic();
?>

To not throw a Fatal error: Call to undefined method Sourcerer::magic() in .../test__get.php.

Answer 1

public function __call($name, $args) {
    if (method_exists($this->apprentice, $name)) {
        return $this->apprentice->$name($args);
    }
    throw Exception("no magic left");
}

ps: use __call for methods as __get is only for properties. And yes, it is better to use call_user_func_array, otherwise arguments are supplied as array to the magic function.

return call_user_func_array(array($this->apprentice, $name), $args);

Answer 2

1. To actually call the method on apprentice, you'll have to actually call it like so:

   return $this->apprentice->$key();
   

2. You're using $source->magic(), which does not invoke the __get method. __get is for variable access like $source->magic, but $source->magic() is a function call. If you want a magic method for function calls, that's __call.

Answer 3

More like __call instead of __get in your case:

class Sourcerer // I work magic with the source
{
    private $apprentice;

    public function __construct(){
        $this->apprentice = new Apprentice();
    }

    public function __call($name, $arguments) {
        if (method_exists($this->apprentice, $name)) {
            return call_user_func_array(array($this->apprentice, $name), $arguments);
        }
        throw Exception("no magic left");
    }
}

Answer 4

Your call would instead be:

$source = new Sourcerer();
$source->apprentice->magic();

Also, I believe the __get() magic method works on properties, not method names.

Finally, in your actual __get() definition, the syntax is wrong: it should be throw new Exception('message');. I'd also move this to an else clause, otherwise it's going to get triggered each call regardless, as it's outside any if/else or other logic.