Diactoros: an epithet for Hermes, meaning literally, "the messenger".
This package supercedes and replaces phly/http.
zend-diactoros
is a PHP package containing implementations of the accepted PSR-7 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.
Install this library using composer:
$ composer require zendframework/zend-diactoros
zend-diactoros
has the following dependencies (which are managed by Composer):
psr/http-message
, which defines interfaces for HTTP messages, including requests and responses.zend-diactoros
provides implementations of each of these.
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.
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 Zend\Diactoros\Request())
->withUri(new Zend\Diactoros\Uri('http://example.com'))
->withMethod('PATCH')
->withAddedHeader('Authorization', 'Bearer ' . $token)
->withAddedHeader('Content-Type', 'application/json');
// OR:
$request = new Zend\Diactoros\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: zend-diactoros
does NOT ship with a client implementation; the above is just an illustration of a possible implementation.)
Server-side applications will need to marshal the incoming request based on superglobals, and will then populate and send a response.
PHP contains a plethora of information about the incoming request, and keeps that information in a variety of locations. Zend\Diactoros\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 Zend\Diactoros\ServerRequest
instance. If any argument is omitted, the associated superglobal will be used.
$request = Zend\Diactoros\ServerRequestFactory::fromGlobals(
$_SERVER,
$_GET,
$_POST,
$_COOKIE,
$_FILES
);
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 Zend\Diactoros\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');
Zend\Diactoros\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
$server = new Zend\Diactoros\Server(
function ($request, $response, $done) {
$response->getBody()->write("Hello world!");
},
$request,
$response
);
// Using the createServer factory, providing it with the various superglobals:
$server = Zend\Diactoros\Server::createServer(
function ($request, $response, $done) {
$response->getBody()->write("Hello world!");
},
$_SERVER,
$_GET,
$_POST,
$_COOKIE,
$_FILES
);
// Using the createServerFromRequest factory, and providing it a request:
$server = Zend\Diactoros\Server::createServerfromRequest(
function ($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).
Zend\Diactoros\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 = []
);
// See psr/http-message's RequestInterface for other methods
}
Requests are immutable. Any methods that would change state -- those prefixed with with
and without
-- all return a new instance with the changes requested.
For server-side applications, Zend\Diactoros\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 = []
);
// See psr/http-message's ServerRequestInterface for other methods.
}
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. Server parameters are considered completely immutable, however, as they cannot be recalculated, and, rather, is a source for other values.
Zend\Diactoros\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 = []
);
// See psr/http-message's ResponseInterface for other methods
}
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.
This static class can be used to marshal a ServerRequest
instance from the PHP environment. The primary entry point is Zend\Diactoros\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,
$_FILES
);
Zend\Diactoros\Uri
is an implementation of Psr\Http\Message\UriInterface
, and models and validates URIs. It implements __toString()
, allowing it to be represented as a string and echo()
'd directly. The following methods are pertinent:
class Uri
{
public function __construct($uri = '');
// See psr/http-message's UriInterface for other methods.
}
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.
Zend\Diactoros\Stream
is an implementation of Psr\Http\Message\StreamInterface
, 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.
Zend\Diactoros\UploadedFile
is an implementation of Psr\Http\Message\UploadedFileInterface
, and provides abstraction around a single uploaded file, including behavior for interacting with it as a stream or moving it to a filesystem location.
In most cases, you will only use the methods defined in the UploadedFileInterface
.
Zend\Diactoros\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 setEmitter(Response\EmitterInterface $emitter);
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 $callback
registered with the server.
If you are using a non-SAPI PHP implementation and wish to use the Server
class, or if you do not want to use the Server
implementation but want to emit a response, this package provides an interface, Zend\Diactoros\Response\EmitterInterface
, defining a method emit()
for emitting the response. A single implementation is currently available, Zend\Diactoros\Response\SapiEmitter
, which will use the native PHP functions header()
and echo
in order to emit the response. If you are using a non-SAPI implementation, you will need to create your own EmitterInterface
implementation.
At times, it's useful to either create a string representation of a message (serialization), or to cast a string or stream message to an object (deserialization). This package provides features for this in Zend\Diactoros\Request\Serializer
and Zend\Diactoros\Response\Serializer
; each provides the following static methods:
fromString($message)
will create either aRequest
orResponse
instance (based on the serializer used) from the string message.fromStream(Psr\Http\Message\StreamInterface $stream)
will create either aRequest
orResponse
instance (based on the serializer used) from the provided stream.toString(Psr\Http\Message\RequestInterface|Psr\Http\Message\ResponseInterface $message)
will create either a string from the provided message.
The deserialization methods (from*()
) will raise exceptions if errors occur while parsing the message. The serialization methods (toString()
) will raise exceptions if required data for serialization is not present in the message instance.