gistfile1.php

<?php

$handlers = array(
    new SecondInvokerFactory,
    new SecondSecondInvokerFactory,
);

function create_chain($invoker, $factory) {
    return $factory($invoker);
}

$chain = array_reduce(array_reverse($handlers), 'get_chain', new Invoker);

gistfile2.php

<?php

interface Handler
{
    public function handle($object);
}

class ChainCallable
{
    protected $callables;

    public function add(callable $callable)
    {
        array_unshift($this->callables, $callable);
    }

    public function __invoke(Handler $handler)
    {
        $reducer = function (Handler $handler, callable $callable) {
            return $callable($handler);
        };

        return array_reduce($this->callable, $reduce, $handler);
    }
}

class EchoHandler implements Handler
{
    public function handle($object)
    {
        echo time();
    }
}

class AroundHandler implements Handler
{
    protected $next;

    public function __construct(Handler $next)
    {
        $this->next = $next;
    }

    public function handle($object)
    {
        echo 'before';

        $this->next->handle($object);

        echo 'after';
    }
}

gistfile3.php

<?php

$chain = new ChainCallable;
$chain->add(function ($next) {
    return new AroundHandler($next);
});

$handler = $chain(new EchoHandler);

// will print "before 2323232323 after"
$handler->handle(new \stdClass);