phly/http

phly/http is a PHP package containing implementations of the proposed PSR HTTP message interfaces, as well as a "server" implementation similar to node's http.Server.

This package exists:

to provide a proof-of-concept of the proposed PSR HTTP message interfaces with relation to server-side applications.
to provide a node-like paradigm for PHP front controllers.
to provide a common methodology for marshaling a request from the server environment.

Installation and Requirements

Install this library using composer:

$ composer require "psr/http-message:~0.8.0" "phly/http:~1.0-dev@dev"

phly/http has the following dependencies (which are managed by Composer):

psr/http-message, which defines interfaces for HTTP messages, including requests and responses. phly/http provides implementations of each of these.

Contributing

Please write unit tests for any features or bug reports you have.
Please run unit tests before opening a pull request. You can do so using ./vendor/bin/phpunit.
Please run CodeSniffer before opening a pull request, and correct any issues. Use the following to run it: ./vendor/bin/phpcs --standard=PSR2 --ignore=test/Bootstrap.php src test.

Usage

Usage will differ based on whether you are writing an HTTP client, or a server-side application.

For HTTP client purposes, you will create and populate a Request instance, and the client should return a Response instance.

For server-side applications, you will create a ServerRequest instance, and populate and return a Response instance.

HTTP Clients

A client will send a request, and return a response. As a developer, you will create and populate the request, and then introspect the response. Both requests and responses are immutable; if you make changes -- e.g., by calling setter methods -- you must capture the return value, as it is a new instance.

// Create a request
$request = (new Phly\Http\Request())
    ->withUri(new Phly\Http\Uri('http://example.com'))
    ->withMethod('PATCH')
    ->withAddedHeader('Authorization', 'Bearer ' . $token)
    ->withAddedHeader('Content-Type', 'application/json');

// OR:
$request = new Phly\Http\Request(
    'http://example.com',
    'PATCH',
    'php://memory',
    [
        'Authorization' => 'Bearer ' . $token,
        'Content-Type'  => 'application/json',
    ]
);

// If you want to set a non-origin-form request target, set the
// request-target explicitly:
$request = $request->withRequestTarget((string) $uri);       // absolute-form
$request = $request->withRequestTarget($uri->getAuthority(); // authority-form
$request = $request->withRequestTarget('*');                 // asterisk-form

// Once you have the instance:
$request->getBody()->write(json_encode($data));
$response = $client->send($request);

printf("Response status: %d (%s)\n", $response->getStatusCode(), $response->getReasonPhrase());
printf("Headers:\n");
foreach ($response->getHeaders() as $header => $values) {
  printf("    %s: %s\n", $header, implode(', ', $values));
}
printf("Message:\n%s\n", $response->getBody());

(Note: phly/http does NOT ship with a client implementation; the above is just an illustration of a possible implementation.)

Server-Side Applications

Server-side applications will need to marshal the incoming request based on superglobals, and will then populate and send a response.

Marshaling an incoming request

PHP contains a plethora of information about the incoming request, and keeps that information in a variety of locations. Phly\Http\ServerRequestFactory::fromGlobals() can simplify marshaling that information into a request instance.

You can call the factory method with or without the following arguments, in the following order:

$server, typically $_SERVER
$query, typically $_GET
$body, typically $_POST
$cookies, typically $_COOKIE
$files, typically $_FILES

The method will then return a Phly\Http\ServerRequest instance. If any argument is omitted, the associated superglobal will be used.

$request = Phly\Http\ServerRequestFactory::fromGlobals(
  $_SERVER,
  $_GET,
  $_POST,
  $_COOKIE,
  $_FILES
);

Manipulating the response

Use the response object to add headers and provide content for the response. Writing to the body does not create a state change in the response, so it can be done without capturing the return value. Manipulating headers does, however.

$response = new Phly\Http\Response();

// Write to the response body:
$response->getBody()->write("some content\n");

// Multiple calls to write() append:
$response->getBody()->write("more content\n"); // now "some content\nmore content\n"

// Add headers
// Note: headers do not need to be added before data is written to the body!
$response = $response
    ->withHeader('Content-Type', 'text/plain')
    ->withAddedHeader('X-Show-Something', 'something');

"Serving" an application

Phly\Http\Server mimics a portion of the API of node's http.Server class. It invokes a callback, passing it an ServerRequest, an Response, and optionally a callback to use for incomplete/unhandled requests.

You can create a server in one of three ways:

// Direct instantiation, with a callback handler, request, and response
$server = new Phly\Http\Server(
    function ($request, $response, $done) {
        $response->getBody()->write("Hello world!");
    },
    $request,
    $response
);

// Using the createServer factory, providing it with the various superglobals:
$server = Phly\Http\Server::createServer(
    function ($request, $response, $done) {
        $response->getBody()->write("Hello world!");
    },
    $_SERVER,
    $_GET,
    $_POST,
    $_COOKIE,
    $_FILES
);

// Using the createServerFromRequest factory, and providing it a request:
$server = Phly\Http\Server::createServerfromRequest(
  function ($request, $response, $done) {
      $response->getBody()->write("Hello world!");
  },
  $request
);

Server callbacks can expect up to three arguments, in the following order:

$request - the request object
$response - the response object
$done - an optional callback to call when complete

Once you have your server instance, you must instruct it to listen:

$server->listen();

At this time, you can optionally provide a callback to listen(); this will be passed to the handler as the third argument ($done):

$server->listen(function ($request, $response, $error = null) {
    if (! $error) {
        return;
    }
    // do something with the error...
});

Typically, the listen callback will be an error handler, and can expect to receive the request, response, and error as its arguments (though the error may be null).

API

Request Message

Phly\Http\Request implements Psr\Http\Message\RequestInterface, and is intended for client-side requests. It includes the following methods:

class Request
{
    public function __construct(
        $uri = null,
        $method = null,
        $body = 'php://memory',
        array $headers = []
    );
    public function getRequestTarget();
    public function getMethod();
    public function getUri();
    public function getProtocolVersion();
    public function getBody();
    public function hasHeader($header);
    public function getHeader($header);
    public function getHeaderLines($header);
    public function getHeaders();
    public function withRequestTarget($requestTarget);
    public function withMethod($method);
    public function withUri(Psr\Http\Message\UriInterface $uri);
    public function withProtocolVersion($version);
    public function withHeader($header, $value);
    public function withAddedHeader($header, $value);
    public function withoutHeader($header);
    public function withBody(Psr\Http\Message\StreamableInterface $body);
}

Requests are immutable. Any methods that would change state -- those prefixed with with and without -- all return a new instance with the changes requested.

ServerRequest Message

For server-side applications, Phly\Http\ServerRequest implements Psr\Http\Message\ServerRequestInterface, which provides access to the elements of an HTTP request, as well as uniform access to the various elements of incoming data. The methods included are:

class ServerRequest
{
    public function __construct(
        array $serverParams = [],
        array $fileParams = [],
        $uri = null,
        $method = null,
        $body = 'php://input',
        array $headers = []
    );
    public function getRequestTarget();
    public function getMethod();
    public function getUri();
    public function getProtocolVersion();
    public function hasHeader($header);
    public function getHeader($header);
    public function getHeaderLines($header);
    public function getHeaders();
    public function getCookieParams();
    public function getQueryParams();
    public function getBody();
    public function getBodyParams();
    public function getAttribute($attribute, $default = NULL);
    public function getAttributes();
    public function getServerParams();
    public function getFileParams();
    public function hasHeader($header);

    public function withRequestTarget($requestTarget);
    public function withMethod($method);
    public function withUri(Psr\Http\Message\UriInterface $uri);
    public function withProtocolVersion($version);
    public function withHeader($header, $value);
    public function withAddedHeader($header, $value);
    public function withoutHeader($header);
    public function withCookieParams(array $cookies);
    public function withQueryParams(array $query);
    public function withBody(Psr\Http\Message\StreamableInterface $stream);
    public function withBodyParams(array $params);
    public function withAttribute($attribute, $value);
    public function withoutAttribute($attribute);
}

The ServerRequest is immutable. Any methods that would change state -- those prefixed with with and without -- all return a new instance with the changes requested. Two input sources, server and file parameters, are considered completely immutable, however, as they cannot be recalculated, and, rather, are the sources for other values.

Response Message

Phly\Http\Response provides an implementation of Psr\Http\Message\ResponseInterface, an object to be used to aggregate response information for both HTTP clients and server-side applications, including headers and message body content. It includes the following:

class Response
{
    public function __construct(
        $body = 'php://memory',
        $statusCode = 200,
        array $headers = []
    );
    public function getProtocolVersion();
    public function getStatusCode();
    public function getReasonPhrase();
    public function getHeader($header);
    public function getHeaderLines($header);
    public function getHeaders();
    public function getBody();
    public function hasHeader($header);
    public function withProtocolVersion($version);
    public function withStatus($code, $reasonPhrase = NULL);
    public function withHeader($header, $value);
    public function withAddedHeader($header, $value);
    public function withoutHeader($header);
    public function withBody(Psr\Http\Message\StreamableInterface $body);
}

Like the Request and ServerRequest, responses are immutable. Any methods that would change state -- those prefixed with with and without -- all return a new instance with the changes requested.

ServerRequestFactory

This static class can be used to marshal a ServerRequest instance from the PHP environment. The primary entry point is Phly\Http\ServerRequestFactory::fromGlobals(array $server, array $query, array $body, array $cookies, array $files). This method will create a new ServerRequest instance with the data provided. Examples of usage are:

// Returns new ServerRequest instance, using values from superglobals:
$request = ServerRequestFactory::fromGlobals(); 

// or

// Returns new ServerRequest instance, using values provided (in this
// case, equivalent to the previous!)
$request = RequestFactory::fromGlobals(
  $_SERVER,
  $_GET,
  $_POST,
  $_COOKIE,
  $_FILES
);

URI

Phly\Http\Uri is an implementation of Psr\Http\Message\UriInterface, and models and validates URIs. It implements __toString(), allowing it to be represented as a string and echo()'d directly. The following methods are pertinent:

class Uri
{
    public function __construct($uri = '');
    public function getScheme();
    public function getAuthority();
    public function getUserInfo();
    public function getHost();
    public function getPort();
    public function getPath();
    public function getQuery();
    public function getFragment();
    public function withScheme($scheme);
    public function withUserInfo($user, $password = null);
    public function withHost($host);
    public function withPort($port);
    public function withPath($path);
    public function withQuery($query);
    public function withFragment($fragment);
    public function __toString();
}

Like the various message objects, URIs are immutable. Any methods that would change state -- those prefixed with with and without -- all return a new instance with the changes requested.

Stream

Phly\Http\Stream is an implementation of Psr\Http\Message\StreamableInterface, and provides a number of facilities around manipulating the composed PHP stream resource. The constructor accepts a stream, which may be either:

a stream identifier; e.g., php://input, a filename, etc.
a PHP stream resource

If a stream identifier is provided, an optional second parameter may be provided, the file mode by which to fopen the stream.

ServerRequest objects by default use a php://input stream set to read-only; Response objects by default use a php://memory with a mode of wb+, allowing binary read/write access.

In most cases, you will not interact with the Stream object directly.

Server

Phly\Http\Server represents a server capable of executing a callback. It has four methods:

class Server
{
    public function __construct(
        callable $callback,
        Psr\Http\Message\ServerRequestInterface $request,
        Psr\Http\Message\ResponseInterface $response
    );
    public static function createServer(
        callable $callback,
        array $server,  // usually $_SERVER
        array $query,   // usually $_GET
        array $body,    // usually $_POST
        array $cookies, // usually $_COOKIE
        array $files    // usually $_FILES
    );
    public static function createServerFromRequest(
        callable $callback,
        Psr\Http\Message\ServerRequestInterface $request,
        Psr\Http\Message\ResponseInterface $response = null
    );
    public function listen(callable $finalHandler = null);
}

You can create an instance of the Server using any of the constructor, createServer(), or createServerFromRequest() methods. If you wish to use the default request and response implementations, createServer($middleware, $_SERVER, $_GET, $_POST, $_COOKIE, $_FILES) is the recommended option, as this method will also marshal the ServerRequest object based on the PHP request environment. If you wish to use your own implementations, pass them to the constructor or createServerFromRequest() method (the latter will create a default Response instance if you omit it).

listen() executes the callback. If a $finalHandler is provided, it will be passed as the third argument to the $callback registered with the server.

acelot/http