PHP Callable Class

__invoke makes an object callable.

<?php
class CallableObject
{
	public function __invoke()
	{
	}
}
?>

Though there is no magic method that makes a class callable e.g. __invokeStatic.

But we can still make a callable class. That’s to define a function with the same name as the class. E.g.

<?php
function CallableClass()
{
	return new CallableClass();
}

class CallableClass
{
	public function __invoke()
	{
	}
}
?>

Note that before PHP 5.6, the constructor signature has to duplicate again as the function signature, this makes it a little bit awakard to define. (Using Reflection won’t be easier either) E.g.

<?php
function CallableClassPhp53($lifeTime)
{
	return new CallableClassPhp53($lifeTime);
}

class CallableClassPhp53
{
	public function __construct($lifeTime)
	{
	}
}
?>

This is solved by the introduction of Variable-length argument lists since PHP 5.6.

<?php
function CallableClassPhp56()
{
	return new CallableClassPhp56(...func_get_args());
}

class CallableClassPhp56
{
	public function __construct($lifeTime)
	{
	}
}
?>