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.

Transcript

1. Composing PHP Applications with Middleware
   Josh Butts
   Zendcon 2016
   

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2. About Me
   • VP of Engineering, offers.com
   • Austin PHP Organizer
   • Play competitive Skee Ball
   • github.com/jimbojsb
   • @jimbojsb
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3. PSR-7
   Lets Start With
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4. What is PSR-7
   • FIG standard for HTTP messages
   • A collection of interfaces
   • By itself, has nothing specific to do with
   middleware
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5. Request - Historically
   • $_SERVER, $_GET, $_POST<, etc
   • apache_request_headers()
   • php://input
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6. Response - Historically
   • header()
   • http_response_code()
   • header_list()
   • echo
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7. URI - Historically
   • parse_url()
   • parse_str()
   • http_build_query()
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8. DID WE END UP HERE?
   How in the hell
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9. PSR-7
   Enter
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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
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11. PSR-7 is a collection of Interfaces
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12. Concrete Implementations of PSR-7
    • Zend\Diactoros
    • GuzzleHTTP\Psr7
    • Slim\Http
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13. MIDDLEWARE
    I thought this talk was about
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14. What is middleware?
    • Turns a Request into a Response
    • Stackable
    • Reusable
    • Dispatachable
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15. PHP Copied This Trend
    • Node.js Connect
    • Ruby Rack
    • Python WSGI
    • Even StackPHP
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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
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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
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18. Pick a dispatcher
    • Zend-Stratagility
    • Relay
    • Radar
    • Slim v3
    • Zend Expressive
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19. Pick a PSR-7 Implementation
    • Do not write one
    • Unless you’re using Slim already just use
    Zend/Diactoros
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20. What does a middleware look like?
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    $middleware = function(
    \Psr\Http\Message\RequestInterface $request,
    \Psr\Http\Message\ResponseInterface $response,
    callable $next) {
    // do the actual stuff
    };
    

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21. It might also look like this
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    $middleware = function(
    \Psr\Http\Message\RequestInterface $request,
    callable $next) {
    // do some stuff
    };
    

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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
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23. LETS LOOK AT CODE
    All that’s fine
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24. QUESTIONS?
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25. JOIND.IN/TALK/70548
    I’d love your feedback
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