Composing PHP Applications with Middleware (Zendcon 2016)

With the advent of the PSR-7 standard, middleware has become a household name in the PHP ecosystem. This talk will cover middleware architecture concepts including a comparison of how middleware is being used in PHP versus other languages. We'll look at how to leverage middleware concepts to build applications from scratch as well as combine off-the-shelf components using middleware as the glue. Of course, we'll also look at some downright dirty tricks that middleware lets you get away with as well.

1. Composing PHP Applications with Middleware Josh Butts Zendcon 2016
2. About Me • VP of Engineering, offers.com • Austin PHP Organizer • Play competitive Skee Ball • github.com/jimbojsb • @jimbojsb 2
3. PSR-7 Lets Start With 3
4. What is PSR-7 • FIG standard for HTTP messages • A collection of interfaces • By itself, has nothing specific to do with middleware 4
5. Request - Historically • $_SERVER, $_GET, $_POST<, etc • apache_request_headers() • php://input 5
6. Response - Historically • header() • http_response_code() • header_list() • echo 6
7. URI - Historically • parse_url() • parse_str() • http_build_query() 7
8. DID WE END UP HERE? How in the hell 8
9. PSR-7 Enter 9
10. But first - More History • 2014 - everyone* has gone out and built and object model of HTTP • Hello World for writing a framework • None of them are compatible • Symfony\HttpFoundation widely used 10
11. PSR-7 is a collection of Interfaces 11
12. Concrete Implementations of PSR-7 • Zend\Diactoros • GuzzleHTTP\Psr7 • Slim\Http 12
13. MIDDLEWARE I thought this talk was about 13
14. What is middleware? • Turns a Request into a Response • Stackable • Reusable • Dispatachable 14
15. PHP Copied This Trend • Node.js Connect • Ruby Rack • Python WSGI • Even StackPHP 15
16. Express.js is getting it right • All middleware all the way down • Even error handlers are middleware • Even the app instance itself is middleware 16
17. Components of a PHP Middleware App • PSR-7 implementation • Collection of middleware • Middleware dispatcher • Any other libraries that will actually do business logic for you 17
18. Pick a dispatcher • Zend-Stratagility • Relay • Radar • Slim v3 • Zend Expressive 18
19. Pick a PSR-7 Implementation • Do not write one • Unless you’re using Slim already just use Zend/Diactoros 19
20. What does a middleware look like? 20 <?php $middleware = function( \Psr\Http\Message\RequestInterface $request, \Psr\Http\Message\ResponseInterface $response, callable $next) { // do the actual stuff };
21. It might also look like this 21 <?php $middleware = function( \Psr\Http\Message\RequestInterface $request, callable $next) { // do some stuff };
22. PSR-15 • There is still some debate as to which is better • It’s like the standard will not pass along the response • Lots of existing middleware out there that would not meet this spec 22
23. LETS LOOK AT CODE All that’s fine 23
24. QUESTIONS? 24
25. JOIND.IN/TALK/70548 I’d love your feedback 25