Integrating Guzzle 6 Asynchronous Requests with ReactPHP

Integrating_Guzzle_6_Asynchronous_Requests_with_ReactPHP.php

<?php

/**
 * Credits to :
 * @see https://gist.github.com/psampaz/7f2aad5d1d54eeeec8ae
 */

use GuzzleHttp\Handler\CurlMultiHandler;
use GuzzleHttp\HandlerStack;
use GuzzleHttp\Middleware;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;
use React\EventLoop\LoopInterface;

use function GuzzleHttp\Promise\queue;
use function GuzzleHttp\choose_handler;
use React\EventLoop\StreamSelectLoop;
use React\EventLoop\TimerInterface;
use React\Promise\Deferred;

use GuzzleHttp\Promise\PromiseInterface as GuzzlePromise;

class ReactHandlerStack extends HandlerStack
{

    /**
     * @var TimerInterface
     */
    protected $timer;

    /**
     * @var callable
     */
    protected $handlerRef;

    /**
     * @var LoopInterface
     */
    protected $loop;

    public function __construct(callable $handler = null)
    {
        $this->handlerRef = $handler;
        parent::__construct($handler);
    }


    /**
     * @param callable|null $handler
     * @return HandlerStack|ReactHandlerStack
     */
    public static function create(callable $handler = null)
    {
        $stack = new static($handler ?: choose_handler());
        $stack->push(Middleware::httpErrors(), 'http_errors');
        $stack->push(Middleware::redirect(), 'allow_redirects');
        $stack->push(Middleware::cookies(), 'cookies');
        $stack->push(Middleware::prepareBody(), 'prepare_body');
        return $stack;
    }

    public static function bindReactPhpPromiseTicker(LoopInterface $loop)
    {
        return (self::create(new CurlMultiHandler()))->enableReactPhpPromiseTicker($loop);
    }

    /**
     * Crea un HandlerStack che funziona con ReactPHP
     *
     * @param LoopInterface $loop
     * @return HandlerStack
     */
    protected function enableReactPhpPromiseTicker(LoopInterface $loop)
    {
        /**
         * Avvia un timer ogni qualvolta parte una prima chiamata, quando le risposte arrivano
         */
        $this->push(function (callable $handler) use($loop)  {
            return function (
                RequestInterface $request,
                array $options
            ) use ($handler,$loop) {
                $that = $this;
                if(!$this->timer) {
                    $this->timer = $loop->addPeriodicTimer($loop instanceof StreamSelectLoop ? 0 : 0.001,\Closure::bind(function($timer)use($that){
                        $this->execute();
                        $that->cancelTimer();
                    },$this->handlerRef,$this->handlerRef));
                }
                return $handler($request, $options);
            };
        },'reactphp_promise_ticker');
        $this->setLoop($loop);
        return $this;
    }

    /**
     * @return LoopInterface
     */
    public function getLoop(): LoopInterface
    {
        return $this->loop;
    }

    /**
     * @param LoopInterface $loop
     * @return ReactHandlerStack
     */
    public function setLoop(LoopInterface $loop): ReactHandlerStack
    {
        $this->loop = $loop;
        return $this;
    }

    public function cancelTimer()
    {
        $this->loop->cancelTimer($this->timer);
        $this->timer = null;
    }
    
    /**         
     * Dont ever mix GuzzlePromise with ReactPhpPromise !!! use instead this wrapper       
     * 
     * @param GuzzlePromise $promise
     * @return Promise|\React\Promise\PromiseInterface
     */
    public static function guzzleToReactPromise(GuzzlePromise $promise)
    {
        $deferred = new Deferred();
        $promise->then(function ($value) use($deferred){
            $deferred->resolve($value);
        }, function ($error) use($deferred) {
            $deferred->reject($error);
        });
        return $deferred->promise();
    }
}

I simplified the code, now the timer is going to be canceled when the execute() method ends, since the promise queue becomes empty