Speed up web APIs in PHP
with Expressive

by Enrico Zimuel
Senior Software Engineer
Rogue Wave Software (USA)

APIConf 2018, Turin (Italy), 21th Jun

About me

Developer since 1996 Senior Software Engineer at Rogue Wave Software Inc. Core team of Apigility, Expressive and Zend Framework TEDx and international speaker Research Programmer at Amsterdam University Co-founder of PUG Torino (Italy)

PHP 7 book

Sviluppare in PHP 7 * pp. 352, Tecniche Nuove, 2017 ISBN 978-88-481-3120-9 * in Italian

Web API

Building a Web API

• Managing the HTTP request and response
• Choosing a representation format
• Choosing an error format
• Filtering & validating input data
• Authenticating HTTP requests
• Authorizing HTTP requests
• Documentation

HTTP request in PHP

Global variables (bad!):

• $_SERVER
• $_POST
• $_GET
• $_FILES
• $_COOKIE

HTTP response in PHP

• http_response_code()
• header(), header_remove(), headers_list(), headers_sent()
• setcookie(), setrawcookie()
• etc

Please OOP!

PSR-7

• PHP Standards Recommendations (PSR)
• Part of PHP Framework Interop Group (PHP FIG)
• PSR-7 is a collection of interfaces for representing HTTP messages as described in RFC 7230 and RFC 7231, and URIs for use with HTTP messages as described in RFC 3986

Example

// Request
$header = $request->getHeader('Accept');
$query  = $request->getQueryParams();
$body   = $request->getBodyParams();

// Response
$response = $response->withStatus(418, "I'm a teapot");
$response = $response->withBodyParams(json_encode($body));

Middleware

Middleware

A function that gets a request and generates a response

function ($request)
{
    // do something with $request
    return $response;
}

Delegating middleware

Create a pipeline of execution

function ($request, $delegate)
{
    // delegating another middleware
    $response = $delegate($request);
    return $response;
}

Example: cache

function ($request, $delegate) use ($cache)
{
    if ($cache->has($request)) {
        return $cache->get($request);
    }
    $response = $delegate($request);
    $cache->set($request, $response);
    return $response;
}

Expressive

The PHP framework for middleware applications

• PSR-7 support (using zend-diactoros)
• PSR-15 support
• Piping workflow (using zend-stratigility)
• Features: routing, dependency injection, templating, error handling
• Last release 3.0.6, 16th April 2018

A basic web API

use Zend\Diactoros\Response\JsonResponse;
use Zend\Expressive\Application;

$container = require 'config/container.php';

$app = $container->get(Application::class);

$app->pipe('/api/ping', function($request) {
    return new JsonResponse(['ack' => time()]);
});
// or $app->pipe('/api/ping', \App\Handler\PingHandler::class);
$app->run();

Request Handler

use Psr\Http\Message\ResponseInterface; // PSR-7
use Psr\Http\Message\ServerRequestInterface; // PSR-7
use Psr\Http\Server\RequestHandlerInterface; // PSR-15
use Zend\Diactoros\Response\JsonResponse;

class PingHandler implements RequestHandlerInterface
{
    public function handle(
        ServerRequestInterface $request
    ) : ResponseInterface
    {
        return new JsonResponse(['ack' => time()]);
    }
}

Example: Routing REST API

$app->route('/api/users[/{id}]', [
    Authentication\AuthenticationMiddleware::class,
    Authorization\AuthorizationMiddleware::class,
    Api\Action\UserAction::class
], ['GET', 'POST', 'PATCH', 'DELETE'], 'api.users');

// or route each HTTP method
$app->get('/api/users[/{id}]', ..., 'api.users.get');
$app->post('/api/users', ..., 'api.users.post');
$app->patch('/api/users/{id}', ..., 'api.users.patch');
$app->delete('/api/users/{id}', ..., 'api.users.delete');

Quick start

You can start using Expressive with composer:

composer create-project zendframework/zend-expressive-skeleton <dir>

Expressive tool for API

• HAL-JSON: zend-expressive-hal
• Problem details: zend-problem-details
• Filtering & validation: zend-inputfilter
• Authentication (HTTP Basic, OAuth2): zend-expressive-authentication
• Authorization (ACL, RBAC): zend-expressive-authorization

REST example

github.com/ezimuel/zend-expressive-api

Swoole

• Swoole is an async programming framework for PHP 7
• PHP extension, install:

  
  pecl install swoole
  

• Released under Apache license 2.0
• More info at swoole.co.uk

Features

• Event-driven, asynchronous programming for PHP
• Async TCP / UDP / HTTP / Websocket / HTTP2 client/server side API
• IPv4 / IPv6 / Unixsocket / TCP/ UDP and SSL / TLS support
• High performance, scalable, support C1000K
• Fast serializer / unserializer
• Milliseconds task scheduler

HTTP Server

$http = new swoole_http_server("127.0.0.1", 9501);

$http->on("start", function ($server) {
    echo "Started at http://127.0.0.1:9501\n";
});

$http->on("request", function ($request, $response) {
    $response->header("Content-Type", "text/plain");
    $response->end("Hello World\n");
});

$http->start();

Expressive with Swoole

Use zendframework/zend-expressive-swoole library
(dev version):

composer require zendframework/zend-expressive-swoole:dev-master

Usage:

php public/index.php

Runs at localhost:8080 by default

Swoole is 4x faster

Thanks!

Contact: enrico.zimuel [at] roguewave.com

This work is licensed under a
Creative Commons Attribution-ShareAlike 3.0 Unported License.
I used reveal.js to make this presentation.