Learning the PHP-FIG HTTP Stack (Midwest PHP 2019)

The PHP-FIG has produced four PSRs relating to HTTP: PSR-7 HTTP message interfaces, PSR-15 HTTP Server Request Handlers, PSR-17 HTTP Factories and PSR-18 HTTP Client. Learn the differences between these PSRs and how they work together to enable a rich set of tools making it easier for applications and libraries to work with HTTP in PHP.

Transcript

1. Learning the
   PHP-FIG HTTP Stack
   Beau Simensen
   Technical Strategy Consultant
   beausimensen.com • astrocasts.com • thatpodcast.io
   

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4. $client = create_http_client(); // implementation specific
   $response = $client ->request('GET', 'http: // www.php.net');
   if ($response ->getStatusCode() == 200) {
   $content = $response ->getContent();
   }
   $response = $client ->request('GET', 'http: //api/returning.json');
   if ($response ->getContentType() == 'application/json') {
   $json = json_decode($response ->getContent());
   }
   

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5. interface ClientInterface
   {
   /**
   * @return ResponseInterface
   */
   public function request($method, $url, array $headers = [], $content = null);
   }
   

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6. –Kris Wallsmith, 2012-03-24
   "[...] I think we should take a step back and start with interfaces for
   an HTTP request and an HTTP response. Once those are done, then
   we can move on to an HTTP client."
   

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7. interface ClientInterface
   {
   /**
   * @return ResponseInterface
   */
   public function sendRequest(RequestInterface $request);
   }
   

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8. –Beau Simensen, 2012-06-17
   "Either the client needs to construct the request itself
   (factory) or we need to provide a PSR request implementation that
   anyone can use."
   

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9. interface ClientInterface
   {
   /**
   * @return RequestInterface
   */
   public function createRequest($method, $url, array $headers = [], $content = null);
   }
   

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10. –Benjamin Eberlei, 2012-03-24
    "Just realized I forgot cookies."
    

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11. –Evert Pot, 2012-03-24
    "If you're taking this approach, you will find that you probably forgot
    a lot of HTTP features :)"
    

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12. –Evert Pot, 2012-03-24
    "If you want to keep things simple, I'd strongly suggest focusing on
    the following..."
    - http method
    - url
    - http version
    - headers
    - stream for body
    - http status code
    - human-readable status
    - http version
    - headers
    - stream for body
    Request Response
    

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13. Modeling HTTP
    Or "How PSR-7 happened"
    

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15. use Psr\Http\Message\RequestInterface;
    use Psr\Http\Message\ResponseInterface;
    class MyHttpClient
    {
    public function send(RequestInterface $request): ResponseInterface
    {
    // ...
    }
    }
    

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20. namespace Symfony\Component\HttpFoundation;
    class Request {
    public function __construct(
    array $query = [],
    array $request = [],
    array $attributes = [],
    array $cookies = [],
    array $files = [],
    array $server = [],
    $content = null
    ) {
    // ...
    }
    }
    

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21. namespace Symfony\Component\HttpFoundation;
    class Request {
    public static function createFromGlobals() {
    return self ::createRequestFromFactory(
    $_GET,
    $_POST,
    [],
    $_COOKIE,
    $_FILES,
    $_SERVER
    );
    }
    }
    

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22. namespace Zend\Http\PhpEnvironment;
    class Request extends \Zend\Http\Request {
    public function __construct() {
    $this ->setEnv(new Parameters($_ENV));
    if ($_GET) {
    $this ->setQuery(new Parameters($_GET));
    }
    if ($_POST) {
    $this ->setPost(new Parameters($_POST));
    }
    if ($_COOKIE) {
    $this ->setCookies(new Parameters($_COOKIE));
    }
    if ($_FILES) {
    $files = $this ->mapPhpFiles();
    $this ->setFiles(new Parameters($files));
    }
    $this ->setServer(new Parameters($_SERVER));
    }
    }
    

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27. $request = Zend\Diactoros\ServerRequestFactory ::fromGlobals(
    $_SERVER,
    $_GET,
    $_POST,
    $_COOKIE,
    $_FILES
    );
    

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29. HTTP Messages are HTTP Messages
    

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31. PSR-7
    HTTP Message Interfaces
    

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32. Guzzle
    http://guzzlephp.org/
    

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33. Zend Diactoros
    https://github.com/zendframework/zend-diactoros
    

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34. Zend Stratigility
    https://github.com/zendframework/zend-stratigility
    

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35. Zend Expressive
    https://github.com/zendframework/zend-expressive
    

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36. Slim
    http://www.slimframework.com/
    

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39. The PHP HTTP group
    https://github.com/php-http
    

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40. HTTP Interop
    https://github.com/http-interop
    

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42. class ApiTheRightWay
    {
    private $client;
    public function __construct($client)
    {
    $this ->client = $client;
    }
    public function getStatus()
    {
    $request = new GuzzleHttp\Psr7\Request();
    $response = $this ->client ->send($request);
    return json_decode($response ->getBody() ->getContents(), true);
    }
    }
    

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43. interface DoublePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    ResponseInterface $response,
    callable $next
    ): ResponseInterface;
    }
    interface SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface;
    }
    

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44. interface DoublePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    ResponseInterface $response,
    callable $next
    ): ResponseInterface;
    }
    interface SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface;
    }
    

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45. __invoke()
    

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46. interface Middleware()
    

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49. –You might be thinking this
    “How is this better?”
    

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50. Completing the Stack
    

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51. –Kris Wallsmith, 2012-03-24
    "[...] I think we should take a step back and start with interfaces for
    an HTTP request and an HTTP response. Once those are done, then
    we can move on to an HTTP client."
    

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52. PSR-15
    HTTP Handlers
    

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53. interface DoublePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    ResponseInterface $response,
    callable $next
    ): ResponseInterface;
    }
    interface SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface;
    }
    

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54. class ChaosMiddleware implements SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface
    {
    if (rand(0, 99) === 0) {
    return (new GuzzleHttp\Psr7\Response(404));
    }
    return $next($request);
    }
    }
    

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55. class ChaosMiddleware implements DoublePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    ResponseInterface $response,
    callable $next
    ): ResponseInterface
    {
    if (rand(0, 99) === 0) {
    return $response ->withStatus(404);
    }
    return $next($request);
    }
    }
    

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56. interface DoublePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    ResponseInterface $response,
    callable $next
    ): ResponseInterface;
    }
    interface SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface;
    }
    

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57. interface DoublePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    ResponseInterface $response,
    callable $next
    ): ResponseInterface;
    }
    interface SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface;
    }
    

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58. –Beau Simensen, That Podcast Episode 45
    “You're going to need the Response.”
    

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59. –Dave Marshall, That Podcast Episode 45
    “Are you though?”
    

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60. –Scary Technical Question
    “But is the ResponseInterface instance even in a usable state?”
    

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61. –My personal soapbox for many, many years...
    “We either pass the object or we introduce factories.”
    

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62. Spoiler alert
    They chose factories.
    

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63. interface DoublePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    ResponseInterface $response,
    callable $next
    ): ResponseInterface;
    }
    interface SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface;
    }
    

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64. namespace Psr\Http\Server;
    use Psr\Http\Message\ResponseInterface;
    use Psr\Http\Message\ServerRequestInterface;
    interface MiddlewareInterface
    {
    public function process(
    ServerRequestInterface $request,
    RequestHandlerInterface $handler
    ): ResponseInterface;
    }
    

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65. namespace Psr\Http\Server;
    use Psr\Http\Message\ResponseInterface;
    use Psr\Http\Message\ServerRequestInterface;
    interface RequestHandlerInterface
    {
    public function handle(ServerRequestInterface $request): ResponseInterface;
    }
    

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78. PSR-17
    HTTP Factories
    

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79. namespace Psr\Http\Message;
    use Psr\Http\Message\RequestInterface;
    use Psr\Http\Message\UriInterface;
    interface RequestFactoryInterface
    {
    public function createRequest(string $method, $uri): RequestInterface;
    }
    

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80. namespace Psr\Http\Message;
    use Psr\Http\Message\ResponseInterface;
    interface ResponseFactoryInterface
    {
    public function createResponse(
    int $code = 200,
    string $reasonPhrase = ''
    ): ResponseInterface;
    }
    

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81. namespace Psr\Http\Message;
    use Psr\Http\Message\ServerRequestInterface;
    use Psr\Http\Message\UriInterface;
    interface ServerRequestFactoryInterface
    {
    public function createServerRequest(
    string $method,
    $uri,
    array $serverParams = []
    ): ServerRequestInterface;
    }
    

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82. namespace Psr\Http\Message;
    use Psr\Http\Message\StreamInterface;
    interface StreamFactoryInterface
    {
    public function createStream(string $content = ''): StreamInterface;
    public function createStreamFromFile(
    string $filename,
    string $mode = 'r'
    ): StreamInterface;
    public function createStreamFromResource($resource): StreamInterface;
    }
    

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83. namespace Psr\Http\Message;
    use Psr\Http\Message\StreamInterface;
    use Psr\Http\Message\UploadedFileInterface;
    interface UploadedFileFactoryInterface
    {
    public function createUploadedFile(
    StreamInterface $stream,
    int $size = null,
    int $error = \UPLOAD_ERR_OK,
    string $clientFilename = null,
    string $clientMediaType = null
    ): UploadedFileInterface;
    }
    

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84. namespace Psr\Http\Message;
    use Psr\Http\Message\UriInterface;
    interface UriFactoryInterface
    {
    public function createUri(string $uri = '') : UriInterface;
    }
    

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85. class ApiTheRightWay
    {
    private $client;
    public function __construct($client)
    {
    $this ->client = $client;
    }
    public function getStatus()
    {
    $request = new GuzzleHttp\Psr7\Request();
    $response = $this ->client ->send($request);
    return json_decode($response ->getBody() ->getContents(), true);
    }
    }
    

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86. class ApiTheRightWay
    {
    private $client;
    private $requestFactory;
    public function __construct($client, RequestFactoryInterface $requestFactory)
    {
    $this ->client = $client;
    $this ->requestFactory = $requestFactory;
    }
    public function getStatus()
    {
    $request = $this ->requestFactory ->createRequest();
    $response = $this ->client ->send($request);
    return json_decode($response ->getBody() ->getContents(), true);
    }
    }
    

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87. class ChaosMiddleware implements SinglePassHttpMiddleware
    {
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface
    {
    if (rand(0, 99) === 0) {
    return (new GuzzleHttp\Psr7\Response(404));
    }
    return $next($request);
    }
    }
    

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88. class ChaosMiddleware implements SinglePassHttpMiddleware
    {
    private $responseFactory;
    public function __construct(ResponseFactoryInterface $responseFactory)
    {
    $this ->responseFactory = $responseFactory;
    }
    public function __invoke(
    RequestInterface $request,
    callable $next
    ): ResponseInterface
    {
    if (rand(0, 99) === 0) {
    return $this ->responseFactory ->createResponse(404);
    }
    return $next($request);
    }
    }
    

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93. PSR-18
    HTTP Client
    

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94. namespace Psr\Http\Client;
    use Psr\Http\Message\RequestInterface;
    use Psr\Http\Message\ResponseInterface;
    interface ClientInterface
    {
    public function sendRequest(RequestInterface $request): ResponseInterface;
    }
    

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95. interface ClientInterface
    {
    /**
    * @return ResponseInterface
    */
    public function sendRequest(RequestInterface $request);
    }
    

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96. class ApiTheRightWay
    {
    private $client;
    private $requestFactory;
    public function __construct($client, RequestFactoryInterface $requestFactory)
    {
    $this ->client = $client;
    $this ->requestFactory = $requestFactory;
    }
    public function getStatus()
    {
    $request = $this ->requestFactory ->createRequest();
    $response = $this ->client ->send($request);
    return json_decode($response ->getBody() ->getContents(), true);
    }
    }
    

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97. class ApiTheRightWay
    {
    private $client;
    private $requestFactory;
    public function __construct(
    ClientInterface $client,
    RequestFactoryInterface $requestFactory
    ) {
    $this ->client = $client;
    $this ->requestFactory = $requestFactory;
    }
    public function getStatus()
    {
    $request = $this ->requestFactory ->createRequest();
    $response = $this ->client ->sendRequest($request);
    return json_decode($response ->getBody() ->getContents(), true);
    }
    }
    

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100. Learning the
     PHP-FIG HTTP Stack
     Beau Simensen
     Technical Strategy Consultant
     beausimensen.com • astrocasts.com • thatpodcast.io
     Thanks!
     

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