Developing middleware
web APIs in PHP 7

by Enrico Zimuel - @ezimuel
Senior Software Engineer
Zend, a Rogue Wave Company (USA)

CloudConf, Turin, 16th March 2017

About me

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

PHP

• PHP: Hypertext Preprocessor
• The most popular server-side language: PHP is used by 82.6% of all the websites (source: w3techs.com)
• Used by Facebook, Wikipedia, Yahoo, Etsy, Flickr, Digg, etc
• 21 years of usage, since 1995
• Full OOP support since PHP 5

PHP 7

Released: 3 December 2015

Last major was PHP 5, 13 July 2004

Last release is 7.1.2 (16 Feb 2017)

PHP 7 performance

Benchmark

$a = [];
for ($i = 0; $i < 1000000; $i++) {
  $a[$i] = ["hello"];
}
echo memory_get_usage(true);

Moving to PHP 7

• Badoo saved one million dollars switching to PHP 7 (source)
• Tumblr reduced the latency and CPU load by half moving to PHP 7 (source)
• Dailymotion handles twice more traffic with same infrastructure switching to PHP 7 (source)

PHP 7 is not only fast!

• Return and Scalar Type Declarations
• Improved Exception hierarchy
• Many fatal errors converted to Exceptions
• Secure random number generator
• Authenticated encryption AEAD (PHP 7.1+)
• Nullable types (PHP 7.1+)
• and more!

Web APIs

API stands for Application Programming Interface and as a term, specifies how software should interact.

Web APIs are delivered over HTTP.

HTTP IN/OUT

Example

Request:

GET /api/version

Response:

HTTP/1.1 200 OK
Connection: close
Content-Length: 17
Content-Type: application/json

{
  "version": "1.0"
}
	

How to develop
a web API in PHP?

Middleware

Middleware

A function that gets a request and generates a response

use Psr\Http\Message\ServerRequestInterface as Request;
use Interop\Http\ServerMiddleware\DelegateInterface;

function (Request $request, DelegateInterface $next)
{
    // doing something with $request...
    // for instance calling the delegate middleware $next
    $response = $next->process($request);
    // manipulate the $response
    return $response;
}

DelegateInterface

namespace Interop\Http\ServerMiddleware;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;

interface DelegateInterface
{
    /**
     * @return ResponseInterface;
     */
    public function process(ServerRequestInterface $request);
}

Expressive 2.0

The PHP framework for Middleware applications

• PSR-7 support (using zend-diactoros)
• Support of lambda middleware (PSR-15) and double pass ($request, $response, $next)
• Piping workflow (using zend-stratigility)
• Features: routing, container-interop (PSR-11), templating, error handling
• Last release 2.0.2, 13th March 2017

Installation

You can install Expressive 2.0 using composer:

composer require zendframework/zend-expressive
                 zendframework/zend-expressive-fastroute
                 zendframework/zend-servicemanager

Create a public folder:

mkdir public

Bootstrap script

public/index.php

use Interop\Http\ServerMiddleware\DelegateInterface;
use Zend\Diactoros\Response\JsonResponse;
use Zend\Expressive\AppFactory;

chdir(dirname(__DIR__));
require 'vendor/autoload.php';

$app = AppFactory::create();
$app->get('/api/ping', function ($request, DelegateInterface $delegate) {
    return new JsonResponse(['ack' => time()]);
});

$app->pipeRoutingMiddleware();
$app->pipeDispatchMiddleware();
$app->run();

Running the API

Start a web server using the public folder.

For instance, using the PHP's built-in web server:

php -S 0.0.0.0:8080 -t public/

Call the API at http://localhost:8080/api/ping

DEMO

Deploy a simple API in the cloud
using Amazon Web Service and Zend Server 9

Thanks!

Contact me: enrico.zimuel [at] roguewave.com

Blog and web site: www.zimuel.it

Follow me: @ezimuel

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