http

Event-driven, streaming HTTP client and server implementation for ReactPHP.

602

119

PHP

HTTP

Event-driven, streaming HTTP client and server implementation for ReactPHP.

This HTTP library provides re-usable implementations for an HTTP client and
server based on ReactPHP’s Socket and
EventLoop components.
Its client component allows you to send any number of async HTTP/HTTPS requests
concurrently.
Its server component allows you to build plaintext HTTP and secure HTTPS servers
that accept incoming HTTP requests from HTTP clients (such as web browsers).
This library provides async, streaming means for all of this, so you can handle
multiple concurrent HTTP requests without blocking.

Table of contents

Quickstart example
Client Usage
Server Usage
API
Install
Tests
License

Quickstart example

Once installed, you can use the following code to access an
HTTP web server and send some simple HTTP GET requests:

<?php

require __DIR__ . '/vendor/autoload.php';

$client = new React\Http\Browser();

$client->get('http://www.google.com/')->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump($response->getHeaders(), (string)$response->getBody());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

This is an HTTP server which responds with Hello World! to every request.

<?php

require __DIR__ . '/vendor/autoload.php';

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    return React\Http\Message\Response::plaintext(
        "Hello World!\n"
    );
});

$socket = new React\Socket\SocketServer('127.0.0.1:8080');
$http->listen($socket);

Client Usage

Request methods

Most importantly, this project provides a Browser object that
offers several methods that resemble the HTTP protocol methods:

$browser->get($url, array $headers = array());
$browser->head($url, array $headers = array());
$browser->post($url, array $headers = array(), string|ReadableStreamInterface $body = '');
$browser->delete($url, array $headers = array(), string|ReadableStreamInterface $body = '');
$browser->put($url, array $headers = array(), string|ReadableStreamInterface $body = '');
$browser->patch($url, array $headers = array(), string|ReadableStreamInterface $body = '');

Each of these methods requires a $url and some optional parameters to send an
HTTP request. Each of these method names matches the respective HTTP request
method, for example the get() method sends an HTTP GET request.

You can optionally pass an associative array of additional $headers that will be
sent with this HTTP request. Additionally, each method will automatically add a
matching Content-Length request header if an outgoing request body is given and its
size is known and non-empty. For an empty request body, if will only include a
Content-Length: 0 request header if the request method usually expects a request
body (only applies to POST, PUT and PATCH HTTP request methods).

If you’re using a streaming request body, it will default
to using Transfer-Encoding: chunked unless you explicitly pass in a matching Content-Length
request header. See also streaming request for more details.

By default, all of the above methods default to sending requests using the
HTTP/1.1 protocol version. If you want to explicitly use the legacy HTTP/1.0
protocol version, you can use the withProtocolVersion()
method. If you want to use any other or even custom HTTP request method, you can
use the request() method.

Each of the above methods supports async operation and either fulfills with a
PSR-7 ResponseInterface
or rejects with an Exception.
Please see the following chapter about promises for more details.

Promises

Sending requests is async (non-blocking), so you can actually send multiple
requests in parallel.
The Browser will respond to each request with a
PSR-7 ResponseInterface
message, the order is not guaranteed.
Sending requests uses a Promise-based
interface that makes it easy to react to when an HTTP request is completed
(i.e. either successfully fulfilled or rejected with an error):

$browser->get($url)->then(
    function (Psr\Http\Message\ResponseInterface $response) {
        var_dump('Response received', $response);
    },
    function (Exception $e) {
        echo 'Error: ' . $e->getMessage() . PHP_EOL;
    }
);

If this looks strange to you, you can also use the more traditional blocking API.

Keep in mind that resolving the Promise with the full response message means the
whole response body has to be kept in memory.
This is easy to get started and works reasonably well for smaller responses
(such as common HTML pages or RESTful or JSON API requests).

You may also want to look into the streaming API:

If you’re dealing with lots of concurrent requests (100+) or
If you want to process individual data chunks as they happen (without having to wait for the full response body) or
If you’re expecting a big response body size (1 MiB or more, for example when downloading binary files) or
If you’re unsure about the response body size (better be safe than sorry when accessing arbitrary remote HTTP endpoints and the response body size is unknown in advance).

Cancellation

The returned Promise is implemented in such a way that it can be cancelled
when it is still pending.
Cancelling a pending promise will reject its value with an Exception and
clean up any underlying resources.

$promise = $browser->get($url);

Loop::addTimer(2.0, function () use ($promise) {
    $promise->cancel();
});

Timeouts

This library uses a very efficient HTTP implementation, so most HTTP requests
should usually be completed in mere milliseconds. However, when sending HTTP
requests over an unreliable network (the internet), there are a number of things
that can go wrong and may cause the request to fail after a time. As such, this
library respects PHP’s default_socket_timeout setting (default 60s) as a timeout
for sending the outgoing HTTP request and waiting for a successful response and
will otherwise cancel the pending request and reject its value with an Exception.

Note that this timeout value covers creating the underlying transport connection,
sending the HTTP request, receiving the HTTP response headers and its full
response body and following any eventual redirects. See also
redirects below to configure the number of redirects to follow (or
disable following redirects altogether) and also streaming
below to not take receiving large response bodies into account for this timeout.

You can use the withTimeout() method to pass a custom timeout
value in seconds like this:

$browser = $browser->withTimeout(10.0);

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // response received within 10 seconds maximum
    var_dump($response->getHeaders());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

Similarly, you can use a bool false to not apply a timeout at all
or use a bool true value to restore the default handling.
See withTimeout() for more details.

If you’re using a streaming response body, the time it
takes to receive the response body stream will not be included in the timeout.
This allows you to keep this incoming stream open for a longer time, such as
when downloading a very large stream or when streaming data over a long-lived
connection.

If you’re using a streaming request body, the time it
takes to send the request body stream will not be included in the timeout. This
allows you to keep this outgoing stream open for a longer time, such as when
uploading a very large stream.

Note that this timeout handling applies to the higher-level HTTP layer. Lower
layers such as socket and DNS may also apply (different) timeout values. In
particular, the underlying socket connection uses the same default_socket_timeout
setting to establish the underlying transport connection. To control this
connection timeout behavior, you can inject a custom Connector
like this:

$browser = new React\Http\Browser(
    new React\Socket\Connector(
        array(
            'timeout' => 5
        )
    )
);

Authentication

This library supports HTTP Basic Authentication
using the Authorization: Basic … request header or allows you to set an explicit
Authorization request header.

By default, this library does not include an outgoing Authorization request
header. If the server requires authentication, if may return a 401 (Unauthorized)
status code which will reject the request by default (see also the
withRejectErrorResponse() method below).

In order to pass authentication details, you can simply pass the username and
password as part of the request URL like this:

$promise = $browser->get('https://user:[email protected]/api');

Note that special characters in the authentication details have to be
percent-encoded, see also rawurlencode().
This example will automatically pass the base64-encoded authentication details
using the outgoing Authorization: Basic … request header. If the HTTP endpoint
you’re talking to requires any other authentication scheme, you can also pass
this header explicitly. This is common when using (RESTful) HTTP APIs that use
OAuth access tokens or JSON Web Tokens (JWT):

$token = 'abc123';

$promise = $browser->get(
    'https://example.com/api',
    array(
        'Authorization' => 'Bearer ' . $token
    )
);

When following redirects, the Authorization request header will never be sent
to any remote hosts by default. When following a redirect where the Location
response header contains authentication details, these details will be sent for
following requests. See also redirects below.

Redirects

By default, this library follows any redirects and obeys 3xx (Redirection)
status codes using the Location response header from the remote server.
The promise will be fulfilled with the last response from the chain of redirects.

$browser->get($url, $headers)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // the final response will end up here
    var_dump($response->getHeaders());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

Any redirected requests will follow the semantics of the original request and
will include the same request headers as the original request except for those
listed below.
If the original request is a temporary (307) or a permanent (308) redirect, request
body and headers will be passed to the redirected request. Otherwise, the request
body will never be passed to the redirected request. Accordingly, each redirected
request will remove any Content-Length and Content-Type request headers.

If the original request used HTTP authentication with an Authorization request
header, this request header will only be passed as part of the redirected
request if the redirected URL is using the same host. In other words, the
Authorizaton request header will not be forwarded to other foreign hosts due to
possible privacy/security concerns. When following a redirect where the Location
response header contains authentication details, these details will be sent for
following requests.

You can use the withFollowRedirects() method to
control the maximum number of redirects to follow or to return any redirect
responses as-is and apply custom redirection logic like this:

$browser = $browser->withFollowRedirects(false);

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // any redirects will now end up here
    var_dump($response->getHeaders());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

See also withFollowRedirects() for more details.

Blocking

As stated above, this library provides you a powerful, async API by default.

You can also integrate this into your traditional, blocking environment by using
reactphp/async. This allows you to simply
await async HTTP requests like this:

use function React\Async\await;

$browser = new React\Http\Browser();

$promise = $browser->get('http://example.com/');

try {
    $response = await($promise);
    // response successfully received
} catch (Exception $e) {
    // an error occurred while performing the request
}

Similarly, you can also process multiple requests concurrently and await an array of Response objects:

use function React\Async\await;
use function React\Promise\all;

$promises = array(
    $browser->get('http://example.com/'),
    $browser->get('http://www.example.org/'),
);

$responses = await(all($promises));

This is made possible thanks to fibers available in PHP 8.1+ and our
compatibility API that also works on all supported PHP versions.
Please refer to reactphp/async for more details.

Keep in mind the above remark about buffering the whole response message in memory.
As an alternative, you may also see one of the following chapters for the
streaming API.

Concurrency

As stated above, this library provides you a powerful, async API. Being able to
send a large number of requests at once is one of the core features of this
project. For instance, you can easily send 100 requests concurrently while
processing SQL queries at the same time.

Remember, with great power comes great responsibility. Sending an excessive
number of requests may either take up all resources on your side or it may even
get you banned by the remote side if it sees an unreasonable number of requests
from your side.

// watch out if array contains many elements
foreach ($urls as $url) {
    $browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
        var_dump($response->getHeaders());
    }, function (Exception $e) {
        echo 'Error: ' . $e->getMessage() . PHP_EOL;
    });
}

As a consequence, it’s usually recommended to limit concurrency on the sending
side to a reasonable value. It’s common to use a rather small limit, as doing
more than a dozen of things at once may easily overwhelm the receiving side. You
can use clue/reactphp-mq as a lightweight
in-memory queue to concurrently do many (but not too many) things at once:

// wraps Browser in a Queue object that executes no more than 10 operations at once
$q = new Clue\React\Mq\Queue(10, null, function ($url) use ($browser) {
    return $browser->get($url);
});

foreach ($urls as $url) {
    $q($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
        var_dump($response->getHeaders());
    }, function (Exception $e) {
        echo 'Error: ' . $e->getMessage() . PHP_EOL;
    });
}

Additional requests that exceed the concurrency limit will automatically be
enqueued until one of the pending requests completes. This integrates nicely
with the existing Promise-based API. Please refer to
clue/reactphp-mq for more details.

This in-memory approach works reasonably well for some thousand outstanding
requests. If you’re processing a very large input list (think millions of rows
in a CSV or NDJSON file), you may want to look into using a streaming approach
instead. See clue/reactphp-flux for
more details.

Streaming response

All of the above examples assume you want to store the whole response body in memory.
This is easy to get started and works reasonably well for smaller responses.

However, there are several situations where it’s usually a better idea to use a
streaming approach, where only small chunks have to be kept in memory:

If you’re dealing with lots of concurrent requests (100+) or
If you want to process individual data chunks as they happen (without having to wait for the full response body) or
If you’re expecting a big response body size (1 MiB or more, for example when downloading binary files) or
If you’re unsure about the response body size (better be safe than sorry when accessing arbitrary remote HTTP endpoints and the response body size is unknown in advance).

You can use the requestStreaming() method to send an
arbitrary HTTP request and receive a streaming response. It uses the same HTTP
message API, but does not buffer the response body in memory. It only processes
the response body in small chunks as data is received and forwards this data
through ReactPHP’s Stream API. This works
for (any number of) responses of arbitrary sizes.

This means it resolves with a normal
PSR-7 ResponseInterface,
which can be used to access the response message parameters as usual.
You can access the message body as usual, however it now also
implements ReactPHP’s ReadableStreamInterface
as well as parts of the PSR-7 StreamInterface.

$browser->requestStreaming('GET', $url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    $body = $response->getBody();
    assert($body instanceof Psr\Http\Message\StreamInterface);
    assert($body instanceof React\Stream\ReadableStreamInterface);

    $body->on('data', function ($chunk) {
        echo $chunk;
    });

    $body->on('error', function (Exception $e) {
        echo 'Error: ' . $e->getMessage() . PHP_EOL;
    });

    $body->on('close', function () {
        echo '[DONE]' . PHP_EOL;
    });
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

You can invoke the following methods on the message body:

$body->on($event, $callback);
$body->eof();
$body->isReadable();
$body->pipe(React\Stream\WritableStreamInterface $dest, array $options = array());
$body->close();
$body->pause();
$body->resume();

Because the message body is in a streaming state, invoking the following methods
doesn’t make much sense:

$body->__toString(); // ''
$body->detach(); // throws BadMethodCallException
$body->getSize(); // null
$body->tell(); // throws BadMethodCallException
$body->isSeekable(); // false
$body->seek(); // throws BadMethodCallException
$body->rewind(); // throws BadMethodCallException
$body->isWritable(); // false
$body->write(); // throws BadMethodCallException
$body->read(); // throws BadMethodCallException
$body->getContents(); // throws BadMethodCallException

Note how timeouts apply slightly differently when using streaming.
In streaming mode, the timeout value covers creating the underlying transport
connection, sending the HTTP request, receiving the HTTP response headers and
following any eventual redirects. In particular, the timeout value
does not take receiving (possibly large) response bodies into account.

If you want to integrate the streaming response into a higher level API, then
working with Promise objects that resolve with Stream objects is often inconvenient.
Consider looking into also using react/promise-stream.
The resulting streaming code could look something like this:

use React\Promise\Stream;

function download(Browser $browser, string $url): React\Stream\ReadableStreamInterface {
    return Stream\unwrapReadable(
        $browser->requestStreaming('GET', $url)->then(function (Psr\Http\Message\ResponseInterface $response) {
            return $response->getBody();
        })
    );
}

$stream = download($browser, $url);
$stream->on('data', function ($data) {
    echo $data;
});
$stream->on('error', function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

See also the requestStreaming() method for more details.

Streaming request

Besides streaming the response body, you can also stream the request body.
This can be useful if you want to send big POST requests (uploading files etc.)
or process many outgoing streams at once.
Instead of passing the body as a string, you can simply pass an instance
implementing ReactPHP’s ReadableStreamInterface
to the request methods like this:

$browser->post($url, array(), $stream)->then(function (Psr\Http\Message\ResponseInterface $response) {
    echo 'Successfully sent.';
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

If you’re using a streaming request body (React\Stream\ReadableStreamInterface), it will
default to using Transfer-Encoding: chunked or you have to explicitly pass in a
matching Content-Length request header like so:

$body = new React\Stream\ThroughStream();
Loop::addTimer(1.0, function () use ($body) {
    $body->end("hello world");
});

$browser->post($url, array('Content-Length' => '11'), $body);

If the streaming request body emits an error event or is explicitly closed
without emitting a successful end event first, the request will automatically
be closed and rejected.

HTTP proxy

You can also establish your outgoing connections through an HTTP CONNECT proxy server
by adding a dependency to clue/reactphp-http-proxy.

HTTP CONNECT proxy servers (also commonly known as “HTTPS proxy” or “SSL proxy”)
are commonly used to tunnel HTTPS traffic through an intermediary (“proxy”), to
conceal the origin address (anonymity) or to circumvent address blocking
(geoblocking). While many (public) HTTP CONNECT proxy servers often limit this
to HTTPS port 443 only, this can technically be used to tunnel any TCP/IP-based
protocol, such as plain HTTP and TLS-encrypted HTTPS.

$proxy = new Clue\React\HttpProxy\ProxyConnector('127.0.0.1:8080');

$connector = new React\Socket\Connector(array(
    'tcp' => $proxy,
    'dns' => false
));

$browser = new React\Http\Browser($connector);

SOCKS proxy

You can also establish your outgoing connections through a SOCKS proxy server
by adding a dependency to clue/reactphp-socks.

The SOCKS proxy protocol family (SOCKS5, SOCKS4 and SOCKS4a) is commonly used to
tunnel HTTP(S) traffic through an intermediary (“proxy”), to conceal the origin
address (anonymity) or to circumvent address blocking (geoblocking). While many
(public) SOCKS proxy servers often limit this to HTTP(S) port 80 and 443
only, this can technically be used to tunnel any TCP/IP-based protocol.

$proxy = new Clue\React\Socks\Client('127.0.0.1:1080');

$connector = new React\Socket\Connector(array(
    'tcp' => $proxy,
    'dns' => false
));

$browser = new React\Http\Browser($connector);

SSH proxy

You can also establish your outgoing connections through an SSH server
by adding a dependency to clue/reactphp-ssh-proxy.

Secure Shell (SSH) is a secure
network protocol that is most commonly used to access a login shell on a remote
server. Its architecture allows it to use multiple secure channels over a single
connection. Among others, this can also be used to create an “SSH tunnel”, which
is commonly used to tunnel HTTP(S) traffic through an intermediary (“proxy”), to
conceal the origin address (anonymity) or to circumvent address blocking
(geoblocking). This can be used to tunnel any TCP/IP-based protocol (HTTP, SMTP,
IMAP etc.), allows you to access local services that are otherwise not accessible
from the outside (database behind firewall) and as such can also be used for
plain HTTP and TLS-encrypted HTTPS.

$proxy = new Clue\React\SshProxy\SshSocksConnector('[email protected]');

$connector = new React\Socket\Connector(array(
    'tcp' => $proxy,
    'dns' => false
));

$browser = new React\Http\Browser($connector);

Unix domain sockets

By default, this library supports transport over plaintext TCP/IP and secure
TLS connections for the http:// and https:// URL schemes respectively.
This library also supports Unix domain sockets (UDS) when explicitly configured.

In order to use a UDS path, you have to explicitly configure the connector to
override the destination URL so that the hostname given in the request URL will
no longer be used to establish the connection:

$connector = new React\Socket\FixedUriConnector(
    'unix:///var/run/docker.sock',
    new React\Socket\UnixConnector()
);

$browser = new React\Http\Browser($connector);

$client->get('http://localhost/info')->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump($response->getHeaders(), (string)$response->getBody());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

Server Usage

HttpServer

The React\Http\HttpServer class is responsible for handling incoming connections and then
processing each incoming HTTP request.

When a complete HTTP request has been received, it will invoke the given
request handler function. This request handler function needs to be passed to
the constructor and will be invoked with the respective request
object and expects a response object in return:

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    return React\Http\Message\Response::plaintext(
        "Hello World!\n"
    );
});

Each incoming HTTP request message is always represented by the
PSR-7 ServerRequestInterface,
see also following request chapter for more details.

Each outgoing HTTP response message is always represented by the
PSR-7 ResponseInterface,
see also following response chapter for more details.

This class takes an optional LoopInterface|null $loop parameter that can be used to
pass the event loop instance to use for this object. You can use a null value
here in order to use the default loop.
This value SHOULD NOT be given unless you’re sure you want to explicitly use a
given event loop instance.

In order to start listening for any incoming connections, the HttpServer needs
to be attached to an instance of
React\Socket\ServerInterface
through the listen() method as described in the following
chapter. In its most simple form, you can attach this to a
React\Socket\SocketServer
in order to start a plaintext HTTP server like this:

$http = new React\Http\HttpServer($handler);

$socket = new React\Socket\SocketServer('0.0.0.0:8080');
$http->listen($socket);

See also the listen() method and the
hello world server example
for more details.

By default, the HttpServer buffers and parses the complete incoming HTTP
request in memory. It will invoke the given request handler function when the
complete request headers and request body has been received. This means the
request object passed to your request handler function will be
fully compatible with PSR-7 (http-message). This provides sane defaults for
80% of the use cases and is the recommended way to use this library unless
you’re sure you know what you’re doing.

On the other hand, buffering complete HTTP requests in memory until they can
be processed by your request handler function means that this class has to
employ a number of limits to avoid consuming too much memory. In order to
take the more advanced configuration out your hand, it respects setting from
your php.ini to apply its
default settings. This is a list of PHP settings this class respects with
their respective default values:

memory_limit 128M
post_max_size 8M // capped at 64K

enable_post_data_reading 1
max_input_nesting_level 64
max_input_vars 1000

file_uploads 1
upload_max_filesize 2M
max_file_uploads 20

In particular, the post_max_size setting limits how much memory a single
HTTP request is allowed to consume while buffering its request body. This
needs to be limited because the server can process a large number of requests
concurrently, so the server may potentially consume a large amount of memory
otherwise. To support higher concurrency by default, this value is capped
at 64K. If you assign a higher value, it will only allow 64K by default.
If a request exceeds this limit, its request body will be ignored and it will
be processed like a request with no request body at all. See below for
explicit configuration to override this setting.

By default, this class will try to avoid consuming more than half of your
memory_limit for buffering multiple concurrent HTTP requests. As such, with
the above default settings of 128M max, it will try to consume no more than
64M for buffering multiple concurrent HTTP requests. As a consequence, it
will limit the concurrency to 1024 HTTP requests with the above defaults.

It is imperative that you assign reasonable values to your PHP ini settings.
It is usually recommended to not support buffering incoming HTTP requests
with a large HTTP request body (e.g. large file uploads). If you want to
increase this buffer size, you will have to also increase the total memory
limit to allow for more concurrent requests (set memory_limit 512M or more)
or explicitly limit concurrency.

In order to override the above buffering defaults, you can configure the
HttpServer explicitly. You can use the
LimitConcurrentRequestsMiddleware and
RequestBodyBufferMiddleware (see below)
to explicitly configure the total number of requests that can be handled at
once like this:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(100), // 100 concurrent buffering handlers
    new React\Http\Middleware\RequestBodyBufferMiddleware(2 * 1024 * 1024), // 2 MiB per request
    new React\Http\Middleware\RequestBodyParserMiddleware(),
    $handler
);

In this example, we allow processing up to 100 concurrent requests at once
and each request can buffer up to 2M. This means you may have to keep a
maximum of 200M of memory for incoming request body buffers. Accordingly,
you need to adjust the memory_limit ini setting to allow for these buffers
plus your actual application logic memory requirements (think 512M or more).

Internally, this class automatically assigns these middleware handlers
automatically when no StreamingRequestMiddleware
is given. Accordingly, you can use this example to override all default
settings to implement custom limits.

As an alternative to buffering the complete request body in memory, you can
also use a streaming approach where only small chunks of data have to be kept
in memory:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    $handler
);

In this case, it will invoke the request handler function once the HTTP
request headers have been received, i.e. before receiving the potentially
much larger HTTP request body. This means the request passed to
your request handler function may not be fully compatible with PSR-7. This is
specifically designed to help with more advanced use cases where you want to
have full control over consuming the incoming HTTP request body and
concurrency settings. See also streaming incoming request
below for more details.

Changelog v1.5.0: This class has been renamed to HttpServer from the
previous Server class in order to avoid any ambiguities.
The previous name has been deprecated and should not be used anymore.

listen()

The listen(React\Socket\ServerInterface $socket): void method can be used to
start listening for HTTP requests on the given socket server instance.

The given React\Socket\ServerInterface
is responsible for emitting the underlying streaming connections. This
HTTP server needs to be attached to it in order to process any
connections and pase incoming streaming data as incoming HTTP request
messages. In its most common form, you can attach this to a
React\Socket\SocketServer
in order to start a plaintext HTTP server like this:

$http = new React\Http\HttpServer($handler);

$socket = new React\Socket\SocketServer('0.0.0.0:8080');
$http->listen($socket);

See also hello world server example
for more details.

This example will start listening for HTTP requests on the alternative
HTTP port 8080 on all interfaces (publicly). As an alternative, it is
very common to use a reverse proxy and let this HTTP server listen on the
localhost (loopback) interface only by using the listen address
127.0.0.1:8080 instead. This way, you host your application(s) on the
default HTTP port 80 and only route specific requests to this HTTP
server.

Likewise, it’s usually recommended to use a reverse proxy setup to accept
secure HTTPS requests on default HTTPS port 443 (TLS termination) and
only route plaintext requests to this HTTP server. As an alternative, you
can also accept secure HTTPS requests with this HTTP server by attaching
this to a React\Socket\SocketServer
using a secure TLS listen address, a certificate file and optional
passphrase like this:

$http = new React\Http\HttpServer($handler);

$socket = new React\Socket\SocketServer('tls://0.0.0.0:8443', array(
    'tls' => array(
        'local_cert' => __DIR__ . '/localhost.pem'
    )
));
$http->listen($socket);

See also hello world HTTPS example
for more details.

Server Request

As seen above, the HttpServer class is responsible for handling
incoming connections and then processing each incoming HTTP request.

The request object will be processed once the request has
been received by the client.
This request object implements the
PSR-7 ServerRequestInterface
which in turn extends the
PSR-7 RequestInterface
and will be passed to the callback function like this.

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
   $body = "The method of the request is: " . $request->getMethod() . "\n";
   $body .= "The requested path is: " . $request->getUri()->getPath() . "\n";

   return React\Http\Message\Response::plaintext(
       $body
   );
});

For more details about the request object, also check out the documentation of
PSR-7 ServerRequestInterface
and
PSR-7 RequestInterface.

Request parameters

The getServerParams(): mixed[] method can be used to
get server-side parameters similar to the $_SERVER variable.
The following parameters are currently available:

REMOTE_ADDR
The IP address of the request sender
REMOTE_PORT
Port of the request sender
SERVER_ADDR
The IP address of the server
SERVER_PORT
The port of the server
REQUEST_TIME
Unix timestamp when the complete request header has been received,
as integer similar to time()
REQUEST_TIME_FLOAT
Unix timestamp when the complete request header has been received,
as float similar to microtime(true)
HTTPS
Set to ‘on’ if the request used HTTPS, otherwise it won’t be set

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $body = "Your IP is: " . $request->getServerParams()['REMOTE_ADDR'] . "\n";

    return React\Http\Message\Response::plaintext(
        $body
    );
});

Query parameters

The getQueryParams(): array method can be used to get the query parameters
similiar to the $_GET variable.

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $queryParams = $request->getQueryParams();

    $body = 'The query parameter "foo" is not set. Click the following link ';
    $body .= '<a href="/?foo=bar">to use query parameter in your request</a>';

    if (isset($queryParams['foo'])) {
        $body = 'The value of "foo" is: ' . htmlspecialchars($queryParams['foo']);
    }

    return React\Http\Message\Response::html(
        $body
    );
});

The response in the above example will return a response body with a link.
The URL contains the query parameter foo with the value bar.
Use htmlentities
like in this example to prevent
Cross-Site Scripting (abbreviated as XSS).

Request body

By default, the Server will buffer and parse the full request body
in memory. This means the given request object includes the parsed request body
and any file uploads.

As an alternative to the default buffering logic, you can also use the
StreamingRequestMiddleware. Jump to the next
chapter to learn more about how to process a
streaming incoming request.

As stated above, each incoming HTTP request is always represented by the
PSR-7 ServerRequestInterface.
This interface provides several methods that are useful when working with the
incoming request body as described below.

The getParsedBody(): null|array|object method can be used to
get the parsed request body, similar to
PHP’s $_POST variable.
This method may return a (possibly nested) array structure with all body
parameters or a null value if the request body could not be parsed.
By default, this method will only return parsed data for requests using
Content-Type: application/x-www-form-urlencoded or Content-Type: multipart/form-data
request headers (commonly used for POST requests for HTML form submission data).

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $name = $request->getParsedBody()['name'] ?? 'anonymous';

    return React\Http\Message\Response::plaintext(
        "Hello $name!\n"
    );
});

See also form upload example for more details.

The getBody(): StreamInterface method can be used to
get the raw data from this request body, similar to
PHP’s php://input stream.
This method returns an instance of the request body represented by the
PSR-7 StreamInterface.
This is particularly useful when using a custom request body that will not
otherwise be parsed by default, such as a JSON (Content-Type: application/json) or
an XML (Content-Type: application/xml) request body (which is commonly used for
POST, PUT or PATCH requests in JSON-based or RESTful/RESTish APIs).

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $data = json_decode((string)$request->getBody());
    $name = $data->name ?? 'anonymous';

    return React\Http\Message\Response::json(
        ['message' => "Hello $name!"]
    );
});

See also JSON API server example for more details.

The getUploadedFiles(): array method can be used to
get the uploaded files in this request, similar to
PHP’s $_FILES variable.
This method returns a (possibly nested) array structure with all file uploads, each represented by the
PSR-7 UploadedFileInterface.
This array will only be filled when using the Content-Type: multipart/form-data
request header (commonly used for POST requests for HTML file uploads).

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $files = $request->getUploadedFiles();
    $name = isset($files['avatar']) ? $files['avatar']->getClientFilename() : 'nothing';

    return React\Http\Message\Response::plaintext(
        "Uploaded $name\n"
    );
});

See also form upload server example for more details.

The getSize(): ?int method can be used to
get the size of the request body, similar to PHP’s $_SERVER['CONTENT_LENGTH'] variable.
This method returns the complete size of the request body measured in number
of bytes as defined by the message boundaries.
This value may be 0 if the request message does not contain a request body
(such as a simple GET request).
This method operates on the buffered request body, i.e. the request body size
is always known, even when the request does not specify a Content-Length request
header or when using Transfer-Encoding: chunked for HTTP/1.1 requests.

Note: The HttpServer automatically takes care of handling requests with the
additional Expect: 100-continue request header. When HTTP/1.1 clients want to
send a bigger request body, they MAY send only the request headers with an
additional Expect: 100-continue request header and wait before sending the actual
(large) message body. In this case the server will automatically send an
intermediary HTTP/1.1 100 Continue response to the client. This ensures you
will receive the request body without a delay as expected.

Streaming incoming request

If you’re using the advanced StreamingRequestMiddleware,
the request object will be processed once the request headers have been received.
This means that this happens irrespective of (i.e. before) receiving the
(potentially much larger) request body.

Note that this is non-standard behavior considered advanced usage. Jump to the
previous chapter to learn more about how to process a buffered request body.

While this may be uncommon in the PHP ecosystem, this is actually a very powerful
approach that gives you several advantages not otherwise possible:

React to requests before receiving a large request body,
such as rejecting an unauthenticated request or one that exceeds allowed
message lengths (file uploads).
Start processing parts of the request body before the remainder of the request
body arrives or if the sender is slowly streaming data.
Process a large request body without having to buffer anything in memory,
such as accepting a huge file upload or possibly unlimited request body stream.

The getBody(): StreamInterface method can be used to
access the request body stream.
In the streaming mode, this method returns a stream instance that implements both the
PSR-7 StreamInterface
and the ReactPHP ReadableStreamInterface.
However, most of the
PSR-7 StreamInterface
methods have been designed under the assumption of being in control of a
synchronous request body.
Given that this does not apply to this server, the following
PSR-7 StreamInterface
methods are not used and SHOULD NOT be called:
tell(), eof(), seek(), rewind(), write() and read().
If this is an issue for your use case and/or you want to access uploaded files,
it’s highly recommended to use a buffered request body or use the
RequestBodyBufferMiddleware instead.
The ReactPHP ReadableStreamInterface
gives you access to the incoming request body as the individual chunks arrive:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    function (Psr\Http\Message\ServerRequestInterface $request) {
        $body = $request->getBody();
        assert($body instanceof Psr\Http\Message\StreamInterface);
        assert($body instanceof React\Stream\ReadableStreamInterface);

        return new React\Promise\Promise(function ($resolve, $reject) use ($body) {
            $bytes = 0;
            $body->on('data', function ($data) use (&$bytes) {
                $bytes += strlen($data);
            });

            $body->on('end', function () use ($resolve, &$bytes){
                $resolve(React\Http\Message\Response::plaintext(
                    "Received $bytes bytes\n"
                ));
            });

            // an error occures e.g. on invalid chunked encoded data or an unexpected 'end' event
            $body->on('error', function (Exception $e) use ($resolve, &$bytes) {
                $resolve(React\Http\Message\Response::plaintext(
                    "Encountered error after $bytes bytes: {$e->getMessage()}\n"
                )->withStatus(React\Http\Message\Response::STATUS_BAD_REQUEST));
            });
        });
    }
);

The above example simply counts the number of bytes received in the request body.
This can be used as a skeleton for buffering or processing the request body.

See also streaming request server example for more details.

The data event will be emitted whenever new data is available on the request
body stream.
The server also automatically takes care of decoding any incoming requests using
Transfer-Encoding: chunked and will only emit the actual payload as data.

The end event will be emitted when the request body stream terminates
successfully, i.e. it was read until its expected end.

The error event will be emitted in case the request stream contains invalid
data for Transfer-Encoding: chunked or when the connection closes before
the complete request stream has been received.
The server will automatically stop reading from the connection and discard all
incoming data instead of closing it.
A response message can still be sent (unless the connection is already closed).

A close event will be emitted after an error or end event.

For more details about the request body stream, check out the documentation of
ReactPHP ReadableStreamInterface.

The getSize(): ?int method can be used to
get the size of the request body, similar to PHP’s $_SERVER['CONTENT_LENGTH'] variable.
This method returns the complete size of the request body measured in number
of bytes as defined by the message boundaries.
This value may be 0 if the request message does not contain a request body
(such as a simple GET request).
This method operates on the streaming request body, i.e. the request body size
may be unknown (null) when using Transfer-Encoding: chunked for HTTP/1.1 requests.

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    function (Psr\Http\Message\ServerRequestInterface $request) {
        $size = $request->getBody()->getSize();
        if ($size === null) {
            $body = "The request does not contain an explicit length. ";
            $body .= "This example does not accept chunked transfer encoding.\n";

            return React\Http\Message\Response::plaintext(
                $body
            )->withStatus(React\Http\Message\Response::STATUS_LENGTH_REQUIRED);
        }

        return React\Http\Message\Response::plaintext(
            "Request body size: " . $size . " bytes\n"
        );
    }
);

Note: The HttpServer automatically takes care of handling requests with the
additional Expect: 100-continue request header. When HTTP/1.1 clients want to
send a bigger request body, they MAY send only the request headers with an
additional Expect: 100-continue request header and wait before sending the actual
(large) message body. In this case the server will automatically send an
intermediary HTTP/1.1 100 Continue response to the client. This ensures you
will receive the streaming request body without a delay as expected.

Request method

Note that the server supports any request method (including custom and non-
standard ones) and all request-target formats defined in the HTTP specs for each
respective method, including normal origin-form requests as well as
proxy requests in absolute-form and authority-form.
The getUri(): UriInterface method can be used to get the effective request
URI which provides you access to individiual URI components.
Note that (depending on the given request-target) certain URI components may
or may not be present, for example the getPath(): string method will return
an empty string for requests in asterisk-form or authority-form.
Its getHost(): string method will return the host as determined by the
effective request URI, which defaults to the local socket address if an HTTP/1.0
client did not specify one (i.e. no Host header).
Its getScheme(): string method will return http or https depending
on whether the request was made over a secure TLS connection to the target host.

The Host header value will be sanitized to match this host component plus the
port component only if it is non-standard for this URI scheme.

You can use getMethod(): string and getRequestTarget(): string to
check this is an accepted request and may want to reject other requests with
an appropriate error code, such as 400 (Bad Request) or 405 (Method Not
Allowed).

The CONNECT method is useful in a tunneling setup (HTTPS proxy) and not
something most HTTP servers would want to care about.
Note that if you want to handle this method, the client MAY send a different
request-target than the Host header value (such as removing default ports)
and the request-target MUST take precendence when forwarding.

Cookie parameters

The getCookieParams(): string[] method can be used to
get all cookies sent with the current request.

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $key = 'greeting';

    if (isset($request->getCookieParams()[$key])) {
        $body = "Your cookie value is: " . $request->getCookieParams()[$key] . "\n";

        return React\Http\Message\Response::plaintext(
            $body
        );
    }

    return React\Http\Message\Response::plaintext(
        "Your cookie has been set.\n"
    )->withHeader('Set-Cookie', $key . '=' . urlencode('Hello world!'));
});

The above example will try to set a cookie on first access and
will try to print the cookie value on all subsequent tries.
Note how the example uses the urlencode() function to encode
non-alphanumeric characters.
This encoding is also used internally when decoding the name and value of cookies
(which is in line with other implementations, such as PHP’s cookie functions).

See also cookie server example for more details.

Invalid request

The HttpServer class supports both HTTP/1.1 and HTTP/1.0 request messages.
If a client sends an invalid request message, uses an invalid HTTP
protocol version or sends an invalid Transfer-Encoding request header value,
the server will automatically send a 400 (Bad Request) HTTP error response
to the client and close the connection.
On top of this, it will emit an error event that can be used for logging
purposes like this:

$http->on('error', function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

Note that the server will also emit an error event if you do not return a
valid response object from your request handler function. See also
invalid response for more details.

Server Response

The callback function passed to the constructor of the HttpServer is
responsible for processing the request and returning a response, which will be
delivered to the client.

This function MUST return an instance implementing
PSR-7 ResponseInterface
object or a
ReactPHP Promise
which resolves with a PSR-7 ResponseInterface object.

This projects ships a Response class which implements the
PSR-7 ResponseInterface.
In its most simple form, you can use it like this:

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    return React\Http\Message\Response::plaintext(
        "Hello World!\n"
    );
});

We use this Response class throughout our project examples, but
feel free to use any other implementation of the
PSR-7 ResponseInterface.
See also the Response class for more details.

Deferred response

The example above returns the response directly, because it needs
no time to be processed.
Using a database, the file system or long calculations
(in fact every action that will take >=1ms) to create your
response, will slow down the server.
To prevent this you SHOULD use a
ReactPHP Promise.
This example shows how such a long-term action could look like:

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $promise = new Promise(function ($resolve, $reject) {
        Loop::addTimer(1.5, function() use ($resolve) {
            $resolve();
        });
    });

    return $promise->then(function () { 
        return React\Http\Message\Response::plaintext(
            "Hello World!"
        );
    });
});

The above example will create a response after 1.5 second.
This example shows that you need a promise,
if your response needs time to created.
The ReactPHP Promise will resolve in a Response object when the request
body ends.
If the client closes the connection while the promise is still pending, the
promise will automatically be cancelled.
The promise cancellation handler can be used to clean up any pending resources
allocated in this case (if applicable).
If a promise is resolved after the client closes, it will simply be ignored.

Streaming outgoing response

The Response class in this project supports to add an instance which implements the
ReactPHP ReadableStreamInterface
for the response body.
So you are able stream data directly into the response body.
Note that other implementations of the
PSR-7 ResponseInterface
may only support strings.

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $stream = new ThroughStream();

    // send some data every once in a while with periodic timer
    $timer = Loop::addPeriodicTimer(0.5, function () use ($stream) {
        $stream->write(microtime(true) . PHP_EOL);
    });

    // end stream after a few seconds
    $timeout = Loop::addTimer(5.0, function() use ($stream, $timer) {
        Loop::cancelTimer($timer);
        $stream->end();
    });

    // stop timer if stream is closed (such as when connection is closed)
    $stream->on('close', function () use ($timer, $timeout) {
        Loop::cancelTimer($timer);
        Loop::cancelTimer($timeout);
    });

    return new React\Http\Message\Response(
        React\Http\Message\Response::STATUS_OK,
        array(
            'Content-Type' => 'text/plain'
        ),
        $stream
    );
});

The above example will emit every 0.5 seconds the current Unix timestamp
with microseconds as float to the client and will end after 5 seconds.
This is just a example you could use of the streaming,
you could also send a big amount of data via little chunks
or use it for body data that needs to calculated.

If the request handler resolves with a response stream that is already closed,
it will simply send an empty response body.
If the client closes the connection while the stream is still open, the
response stream will automatically be closed.
If a promise is resolved with a streaming body after the client closes, the
response stream will automatically be closed.
The close event can be used to clean up any pending resources allocated
in this case (if applicable).

Note that special care has to be taken if you use a body stream instance that
implements ReactPHP’s
DuplexStreamInterface
(such as the ThroughStream in the above example).

For most cases, this will simply only consume its readable side and forward
(send) any data that is emitted by the stream, thus entirely ignoring the
writable side of the stream.
If however this is either a 101 (Switching Protocols) response or a 2xx
(Successful) response to a CONNECT method, it will also write data to the
writable side of the stream.
This can be avoided by either rejecting all requests with the CONNECT
method (which is what most normal origin HTTP servers would likely do) or
or ensuring that only ever an instance of
ReactPHP’s ReadableStreamInterface
is used.

The 101 (Switching Protocols) response code is useful for the more advanced
Upgrade requests, such as upgrading to the WebSocket protocol or
implementing custom protocol logic that is out of scope of the HTTP specs and
this HTTP library.
If you want to handle the Upgrade: WebSocket header, you will likely want
to look into using Ratchet instead.
If you want to handle a custom protocol, you will likely want to look into the
HTTP specs and also see
examples #81 and #82 for more details.
In particular, the 101 (Switching Protocols) response code MUST NOT be used
unless you send an Upgrade response header value that is also present in
the corresponding HTTP/1.1 Upgrade request header value.
The server automatically takes care of sending a Connection: upgrade
header value in this case, so you don’t have to.

The CONNECT method is useful in a tunneling setup (HTTPS proxy) and not
something most origin HTTP servers would want to care about.
The HTTP specs define an opaque “tunneling mode” for this method and make no
use of the message body.
For consistency reasons, this library uses a DuplexStreamInterface in the
response body for tunneled application data.
This implies that that a 2xx (Successful) response to a CONNECT request
can in fact use a streaming response body for the tunneled application data,
so that any raw data the client sends over the connection will be piped
through the writable stream for consumption.
Note that while the HTTP specs make no use of the request body for CONNECT
requests, one may still be present. Normal request body processing applies
here and the connection will only turn to “tunneling mode” after the request
body has been processed (which should be empty in most cases).
See also HTTP CONNECT server example for more details.

Response length

If the response body size is known, a Content-Length response header will be
added automatically. This is the most common use case, for example when using
a string response body like this:

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    return React\Http\Message\Response::plaintext(
        "Hello World!\n"
    );
});

If the response body size is unknown, a Content-Length response header can not
be added automatically. When using a streaming outgoing response
without an explicit Content-Length response header, outgoing HTTP/1.1 response
messages will automatically use Transfer-Encoding: chunked while legacy HTTP/1.0
response messages will contain the plain response body. If you know the length
of your streaming response body, you MAY want to specify it explicitly like this:

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    $stream = new ThroughStream();

    Loop::addTimer(2.0, function () use ($stream) {
        $stream->end("Hello World!\n");
    });

    return new React\Http\Message\Response(
        React\Http\Message\Response::STATUS_OK,
        array(
            'Content-Length' => '13',
            'Content-Type' => 'text/plain',
        ),
        $stream
    );
});

Any response to a HEAD request and any response with a 1xx (Informational),
204 (No Content) or 304 (Not Modified) status code will not include a
message body as per the HTTP specs.
This means that your callback does not have to take special care of this and any
response body will simply be ignored.

Similarly, any 2xx (Successful) response to a CONNECT request, any response
with a 1xx (Informational) or 204 (No Content) status code will not
include a Content-Length or Transfer-Encoding header as these do not apply
to these messages.
Note that a response to a HEAD request and any response with a 304 (Not
Modified) status code MAY include these headers even though
the message does not contain a response body, because these header would apply
to the message if the same request would have used an (unconditional) GET.

Invalid response

As stated above, each outgoing HTTP response is always represented by the
PSR-7 ResponseInterface.
If your request handler function returns an invalid value or throws an
unhandled Exception or Throwable, the server will automatically send a 500
(Internal Server Error) HTTP error response to the client.
On top of this, it will emit an error event that can be used for logging
purposes like this:

$http->on('error', function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
    if ($e->getPrevious() !== null) {
        echo 'Previous: ' . $e->getPrevious()->getMessage() . PHP_EOL;
    }
});

Note that the server will also emit an error event if the client sends an
invalid HTTP request that never reaches your request handler function. See
also invalid request for more details.
Additionally, a streaming incoming request body
can also emit an error event on the request body.

The server will only send a very generic 500 (Interval Server Error) HTTP
error response without any further details to the client if an unhandled
error occurs. While we understand this might make initial debugging harder,
it also means that the server does not leak any application details or stack
traces to the outside by default. It is usually recommended to catch any
Exception or Throwable within your request handler function or alternatively
use a middleware to avoid this generic error handling and
create your own HTTP response message instead.

Default response headers

When a response is returned from the request handler function, it will be
processed by the HttpServer and then sent back to the client.

A Server: ReactPHP/1 response header will be added automatically. You can add
a custom Server response header like this:

$http = new React\Http\HttpServer(function (ServerRequestInterface $request) {
    return new React\Http\Message\Response(
        React\Http\Message\Response::STATUS_OK,
        array(
            'Server' => 'PHP/3'
        )
    );
});

If you do not want to send this Sever response header at all (such as when you
don’t want to expose the underlying server software), you can use an empty
string value like this:

$http = new React\Http\HttpServer(function (ServerRequestInterface $request) {
    return new React\Http\Message\Response(
        React\Http\Message\Response::STATUS_OK,
        array(
            'Server' => ''
        )
    );
});

A Date response header will be added automatically with the current system
date and time if none is given. You can add a custom Date response header
like this:

$http = new React\Http\HttpServer(function (ServerRequestInterface $request) {
    return new React\Http\Message\Response(
        React\Http\Message\Response::STATUS_OK,
        array(
            'Date' => gmdate('D, d M Y H:i:s \G\M\T')
        )
    );
});

If you do not want to send this Date response header at all (such as when you
don’t have an appropriate clock to rely on), you can use an empty string value
like this:

$http = new React\Http\HttpServer(function (ServerRequestInterface $request) {
    return new React\Http\Message\Response(
        React\Http\Message\Response::STATUS_OK,
        array(
            'Date' => ''
        )
    );
});

The HttpServer class will automatically add the protocol version of the request,
so you don’t have to. For instance, if the client sends the request using the
HTTP/1.1 protocol version, the response message will also use the same protocol
version, no matter what version is returned from the request handler function.

The server supports persistent connections. An appropriate Connection: keep-alive
or Connection: close response header will be added automatically, respecting the
matching request header value and HTTP default header values. The server is
responsible for handling the Connection response header, so you SHOULD NOT pass
this response header yourself, unless you explicitly want to override the user’s
choice with a Connection: close response header.

Middleware

As documented above, the HttpServer accepts a single request handler
argument that is responsible for processing an incoming HTTP request and then
creating and returning an outgoing HTTP response.

Many common use cases involve validating, processing, manipulating the incoming
HTTP request before passing it to the final business logic request handler.
As such, this project supports the concept of middleware request handlers.

Custom middleware

A middleware request handler is expected to adhere the following rules:

It is a valid callable.
It accepts an instance implementing
PSR-7 ServerRequestInterface
as first argument and an optional callable as second argument.
It returns either:
- An instance implementing
  PSR-7 ResponseInterface
  for direct consumption.
- Any promise which can be consumed by
  Promise\resolve() resolving to a
  PSR-7 ResponseInterface
  for deferred consumption.
- It MAY throw an Exception (or return a rejected promise) in order to
  signal an error condition and abort the chain.
It calls $next($request) to continue processing the next middleware
request handler or returns explicitly without calling $next to
abort the chain.
- The $next request handler (recursively) invokes the next request
  handler from the chain with the same logic as above and returns (or throws)
  as above.
- The $request may be modified prior to calling $next($request) to
  change the incoming request the next middleware operates on.
- The $next return value may be consumed to modify the outgoing response.
- The $next request handler MAY be called more than once if you want to
  implement custom “retry” logic etc.

Note that this very simple definition allows you to use either anonymous
functions or any classes that use the magic __invoke() method.
This allows you to easily create custom middleware request handlers on the fly
or use a class based approach to ease using existing middleware implementations.

While this project does provide the means to use middleware implementations,
it does not aim to define how middleware implementations should look like.
We realize that there’s a vivid ecosystem of middleware implementations and
ongoing effort to standardize interfaces between these with
PSR-15 (HTTP Server Request Handlers)
and support this goal.
As such, this project only bundles a few middleware implementations that are
required to match PHP’s request behavior (see below) and otherwise actively
encourages Third-Party Middleware implementations.

In order to use middleware request handlers, simply pass a list of all
callables as defined above to the HttpServer.
The following example adds a middleware request handler that adds the current time to the request as a
header (Request-Time) and a final request handler that always returns a 200 OK status code without a body:

$http = new React\Http\HttpServer(
    function (Psr\Http\Message\ServerRequestInterface $request, callable $next) {
        $request = $request->withHeader('Request-Time', time());
        return $next($request);
    },
    function (Psr\Http\Message\ServerRequestInterface $request) {
        return new React\Http\Message\Response(React\Http\Message\Response::STATUS_OK);
    }
);

Note how the middleware request handler and the final request handler have a
very simple (and similar) interface. The only difference is that the final
request handler does not receive a $next handler.

Similarly, you can use the result of the $next middleware request handler
function to modify the outgoing response.
Note that as per the above documentation, the $next middleware request handler may return a
PSR-7 ResponseInterface
directly or one wrapped in a promise for deferred resolution.
In order to simplify handling both paths, you can simply wrap this in a
Promise\resolve() call like this:

$http = new React\Http\HttpServer(
    function (Psr\Http\Message\ServerRequestInterface $request, callable $next) {
        $promise = React\Promise\resolve($next($request));
        return $promise->then(function (ResponseInterface $response) {
            return $response->withHeader('Content-Type', 'text/html');
        });
    },
    function (Psr\Http\Message\ServerRequestInterface $request) {
        return new React\Http\Message\Response(React\Http\Message\Response::STATUS_OK);
    }
);

Note that the $next middleware request handler may also throw an
Exception (or return a rejected promise) as described above.
The previous example does not catch any exceptions and would thus signal an
error condition to the HttpServer.
Alternatively, you can also catch any Exception to implement custom error
handling logic (or logging etc.) by wrapping this in a
Promise like this:

$http = new React\Http\HttpServer(
    function (Psr\Http\Message\ServerRequestInterface $request, callable $next) {
        $promise = new React\Promise\Promise(function ($resolve) use ($next, $request) {
            $resolve($next($request));
        });
        return $promise->then(null, function (Exception $e) {
            return React\Http\Message\Response::plaintext(
                'Internal error: ' . $e->getMessage() . "\n"
            )->withStatus(React\Http\Message\Response::STATUS_INTERNAL_SERVER_ERROR);
        });
    },
    function (Psr\Http\Message\ServerRequestInterface $request) {
        if (mt_rand(0, 1) === 1) {
            throw new RuntimeException('Database error');
        }
        return new React\Http\Message\Response(React\Http\Message\Response::STATUS_OK);
    }
);

Third-Party Middleware

While this project does provide the means to use middleware implementations
(see above), it does not aim to define how middleware implementations should
look like. We realize that there’s a vivid ecosystem of middleware
implementations and ongoing effort to standardize interfaces between these with
PSR-15 (HTTP Server Request Handlers)
and support this goal.
As such, this project only bundles a few middleware implementations that are
required to match PHP’s request behavior (see
middleware implementations) and otherwise actively
encourages third-party middleware implementations.

While we would love to support PSR-15 directly in react/http, we understand
that this interface does not specifically target async APIs and as such does
not take advantage of promises for deferred responses.
The gist of this is that where PSR-15 enforces a
PSR-7 ResponseInterface
return value, we also accept a PromiseInterface<ResponseInterface>.
As such, we suggest using the external
PSR-15 middleware adapter
that uses on the fly monkey patching of these return values which makes using
most PSR-15 middleware possible with this package without any changes required.

Other than that, you can also use the above middleware definition
to create custom middleware. A non-exhaustive list of third-party middleware can
be found at the middleware wiki.
If you build or know a custom middleware, make sure to let the world know and
feel free to add it to this list.

API

Browser

The React\Http\Browser is responsible for sending HTTP requests to your HTTP server
and keeps track of pending incoming HTTP responses.

$browser = new React\Http\Browser();

This class takes two optional arguments for more advanced usage:

// constructor signature as of v1.5.0
$browser = new React\Http\Browser(?ConnectorInterface $connector = null, ?LoopInterface $loop = null);

// legacy constructor signature before v1.5.0
$browser = new React\Http\Browser(?LoopInterface $loop = null, ?ConnectorInterface $connector = null);

If you need custom connector settings (DNS resolution, TLS parameters, timeouts,
proxy servers etc.), you can explicitly pass a custom instance of the
ConnectorInterface:

$connector = new React\Socket\Connector(array(
    'dns' => '127.0.0.1',
    'tcp' => array(
        'bindto' => '192.168.10.1:0'
    ),
    'tls' => array(
        'verify_peer' => false,
        'verify_peer_name' => false
    )
));

$browser = new React\Http\Browser($connector);

Note that the browser class is final and shouldn’t be extended, it is likely to be marked final in a future release.

get()

The get(string $url, array $headers = array()): PromiseInterface<ResponseInterface> method can be used to
send an HTTP GET request.

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump((string)$response->getBody());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

post()

The post(string $url, array $headers = array(), string|ReadableStreamInterface $body = ''): PromiseInterface<ResponseInterface> method can be used to
send an HTTP POST request.

$browser->post(
    $url,
    [
        'Content-Type' => 'application/json'
    ],
    json_encode($data)
)->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump(json_decode((string)$response->getBody()));
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

head()

The head(string $url, array $headers = array()): PromiseInterface<ResponseInterface> method can be used to
send an HTTP HEAD request.

$browser->head($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump($response->getHeaders());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

patch()

The patch(string $url, array $headers = array(), string|ReadableStreamInterface $body = ''): PromiseInterface<ResponseInterface> method can be used to
send an HTTP PATCH request.

$browser->patch(
    $url,
    [
        'Content-Type' => 'application/json'
    ],
    json_encode($data)
)->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump(json_decode((string)$response->getBody()));
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

$body = new React\Stream\ThroughStream();
Loop::addTimer(1.0, function () use ($body) {
    $body->end("hello world");
});

$browser->patch($url, array('Content-Length' => '11'), $body);

put()

The put(string $url, array $headers = array(), string|ReadableStreamInterface $body = ''): PromiseInterface<ResponseInterface> method can be used to
send an HTTP PUT request.

$browser->put(
    $url,
    [
        'Content-Type' => 'text/xml'
    ],
    $xml->asXML()
)->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump((string)$response->getBody());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

delete()

The delete(string $url, array $headers = array(), string|ReadableStreamInterface $body = ''): PromiseInterface<ResponseInterface> method can be used to
send an HTTP DELETE request.

$browser->delete($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump((string)$response->getBody());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

request()

The request(string $method, string $url, array $headers = array(), string|ReadableStreamInterface $body = ''): PromiseInterface<ResponseInterface> method can be used to
send an arbitrary HTTP request.

The preferred way to send an HTTP request is by using the above
request methods, for example the get()
method to send an HTTP GET request.

As an alternative, if you want to use a custom HTTP request method, you
can use this method:

$browser->request('OPTIONS', $url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    var_dump((string)$response->getBody());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

This method will automatically add a matching Content-Length request
header if the size of the outgoing request body is known and non-empty.
For an empty request body, if will only include a Content-Length: 0
request header if the request method usually expects a request body (only
applies to POST, PUT and PATCH).

If you’re using a streaming request body (ReadableStreamInterface), it
will default to using Transfer-Encoding: chunked or you have to
explicitly pass in a matching Content-Length request header like so:

$body = new React\Stream\ThroughStream();
Loop::addTimer(1.0, function () use ($body) {
    $body->end("hello world");
});

$browser->request('POST', $url, array('Content-Length' => '11'), $body);

requestStreaming()

The requestStreaming(string $method, string $url, array $headers = array(), string|ReadableStreamInterface $body = ''): PromiseInterface<ResponseInterface> method can be used to
send an arbitrary HTTP request and receive a streaming response without buffering the response body.

The preferred way to send an HTTP request is by using the above
request methods, for example the get()
method to send an HTTP GET request. Each of these methods will buffer
the whole response body in memory by default. This is easy to get started
and works reasonably well for smaller responses.

In some situations, it’s a better idea to use a streaming approach, where
only small chunks have to be kept in memory. You can use this method to
send an arbitrary HTTP request and receive a streaming response. It uses
the same HTTP message API, but does not buffer the response body in
memory. It only processes the response body in small chunks as data is
received and forwards this data through ReactPHP’s Stream API.
This works for (any number of) responses of arbitrary sizes.

$browser->requestStreaming('GET', $url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    $body = $response->getBody();
    assert($body instanceof Psr\Http\Message\StreamInterface);
    assert($body instanceof React\Stream\ReadableStreamInterface);

    $body->on('data', function ($chunk) {
        echo $chunk;
    });

    $body->on('error', function (Exception $e) {
        echo 'Error: ' . $e->getMessage() . PHP_EOL;
    });

    $body->on('close', function () {
        echo '[DONE]' . PHP_EOL;
    });
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

See also ReactPHP’s ReadableStreamInterface
and the streaming response for more details,
examples and possible use-cases.

$body = new React\Stream\ThroughStream();
Loop::addTimer(1.0, function () use ($body) {
    $body->end("hello world");
});

$browser->requestStreaming('POST', $url, array('Content-Length' => '11'), $body);

withTimeout()

The withTimeout(bool|number $timeout): Browser method can be used to
change the maximum timeout used for waiting for pending requests.

You can pass in the number of seconds to use as a new timeout value:

$browser = $browser->withTimeout(10.0);

You can pass in a bool false to disable any timeouts. In this case,
requests can stay pending forever:

$browser = $browser->withTimeout(false);

You can pass in a bool true to re-enable default timeout handling. This
will respects PHP’s default_socket_timeout setting (default 60s):

$browser = $browser->withTimeout(true);

See also timeouts for more details about timeout handling.

Notice that the Browser is an immutable object, i.e. this
method actually returns a new Browser instance with the
given timeout value applied.

withFollowRedirects()

The withFollowRedirects(bool|int $followRedirects): Browser method can be used to
change how HTTP redirects will be followed.

You can pass in the maximum number of redirects to follow:

$browser = $browser->withFollowRedirects(5);

The request will automatically be rejected when the number of redirects
is exceeded. You can pass in a 0 to reject the request for any
redirects encountered:

$browser = $browser->withFollowRedirects(0);

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // only non-redirected responses will now end up here
    var_dump($response->getHeaders());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

You can pass in a bool false to disable following any redirects. In
this case, requests will resolve with the redirection response instead
of following the Location response header:

$browser = $browser->withFollowRedirects(false);

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // any redirects will now end up here
    var_dump($response->getHeaderLine('Location'));
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

You can pass in a bool true to re-enable default redirect handling.
This defaults to following a maximum of 10 redirects:

$browser = $browser->withFollowRedirects(true);

See also redirects for more details about redirect handling.

Notice that the Browser is an immutable object, i.e. this
method actually returns a new Browser instance with the
given redirect setting applied.

withRejectErrorResponse()

The withRejectErrorResponse(bool $obeySuccessCode): Browser method can be used to
change whether non-successful HTTP response status codes (4xx and 5xx) will be rejected.

You can pass in a bool false to disable rejecting incoming responses
that use a 4xx or 5xx response status code. In this case, requests will
resolve with the response message indicating an error condition:

$browser = $browser->withRejectErrorResponse(false);

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // any HTTP response will now end up here
    var_dump($response->getStatusCode(), $response->getReasonPhrase());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

You can pass in a bool true to re-enable default status code handling.
This defaults to rejecting any response status codes in the 4xx or 5xx
range with a ResponseException:

$browser = $browser->withRejectErrorResponse(true);

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // any successful HTTP response will now end up here
    var_dump($response->getStatusCode(), $response->getReasonPhrase());
}, function (Exception $e) {
    if ($e instanceof React\Http\Message\ResponseException) {
        // any HTTP response error message will now end up here
        $response = $e->getResponse();
        var_dump($response->getStatusCode(), $response->getReasonPhrase());
    } else {
        echo 'Error: ' . $e->getMessage() . PHP_EOL;
    }
});

Notice that the Browser is an immutable object, i.e. this
method actually returns a new Browser instance with the
given setting applied.

withBase()

The withBase(string|null $baseUrl): Browser method can be used to
change the base URL used to resolve relative URLs to.

If you configure a base URL, any requests to relative URLs will be
processed by first resolving this relative to the given absolute base
URL. This supports resolving relative path references (like ../ etc.).
This is particularly useful for (RESTful) API calls where all endpoints
(URLs) are located under a common base URL.

$browser = $browser->withBase('http://api.example.com/v3/');

// will request http://api.example.com/v3/users
$browser->get('users')->then(…);

You can pass in a null base URL to return a new instance that does not
use a base URL:

$browser = $browser->withBase(null);

Accordingly, any requests using relative URLs to a browser that does not
use a base URL can not be completed and will be rejected without sending
a request.

This method will throw an InvalidArgumentException if the given
$baseUrl argument is not a valid URL.

Notice that the Browser is an immutable object, i.e. the withBase() method
actually returns a new Browser instance with the given base URL applied.

withProtocolVersion()

The withProtocolVersion(string $protocolVersion): Browser method can be used to
change the HTTP protocol version that will be used for all subsequent requests.

All the above request methods default to sending
requests as HTTP/1.1. This is the preferred HTTP protocol version which
also provides decent backwards-compatibility with legacy HTTP/1.0
servers. As such, there should rarely be a need to explicitly change this
protocol version.

If you want to explicitly use the legacy HTTP/1.0 protocol version, you
can use this method:

$browser = $browser->withProtocolVersion('1.0');

$browser->get($url)->then(…);

Notice that the Browser is an immutable object, i.e. this
method actually returns a new Browser instance with the
new protocol version applied.

withResponseBuffer()

The withResponseBuffer(int $maximumSize): Browser method can be used to
change the maximum size for buffering a response body.

By default, the response body buffer will be limited to 16 MiB. If the
response body exceeds this maximum size, the request will be rejected.

You can pass in the maximum number of bytes to buffer:

$browser = $browser->withResponseBuffer(1024 * 1024);

$browser->get($url)->then(function (Psr\Http\Message\ResponseInterface $response) {
    // response body will not exceed 1 MiB
    var_dump($response->getHeaders(), (string) $response->getBody());
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

Note that the response body buffer has to be kept in memory for each
pending request until its transfer is completed and it will only be freed
after a pending request is fulfilled. As such, increasing this maximum
buffer size to allow larger response bodies is usually not recommended.
Instead, you can use the requestStreaming() method
to receive responses with arbitrary sizes without buffering. Accordingly,
this maximum buffer size setting has no effect on streaming responses.

Notice that the Browser is an immutable object, i.e. this
method actually returns a new Browser instance with the
given setting applied.

withHeader()

The withHeader(string $header, string $value): Browser method can be used to
add a request header for all following requests.

$browser = $browser->withHeader('User-Agent', 'ACME');

$browser->get($url)->then(…);

Note that the new header will overwrite any headers previously set with
the same name (case-insensitive). Following requests will use these headers
by default unless they are explicitly set for any requests.

withoutHeader()

The withoutHeader(string $header): Browser method can be used to
remove any default request headers previously set via
the withHeader() method.

$browser = $browser->withoutHeader('User-Agent');

$browser->get($url)->then(…);

Note that this method only affects the headers which were set with the
method withHeader(string $header, string $value): Browser

React\Http\Message

Response

The React\Http\Message\Response class can be used to
represent an outgoing server response message.

$response = new React\Http\Message\Response(
    React\Http\Message\Response::STATUS_OK,
    array(
        'Content-Type' => 'text/html'
    ),
    "<html>Hello world!</html>\n"
);

This class implements the
PSR-7 ResponseInterface
which in turn extends the
PSR-7 MessageInterface.

On top of this, this class implements the
PSR-7 Message Util StatusCodeInterface
which means that most common HTTP status codes are available as class
constants with the STATUS_* prefix. For instance, the 200 OK and
404 Not Found status codes can used as Response::STATUS_OK and
Response::STATUS_NOT_FOUND respectively.

Internally, this implementation builds on top of a base class which is
considered an implementation detail that may change in the future.

html()

The static html(string $html): Response method can be used to
create an HTML response.

$html = <<<HTML
<!doctype html>
<html>
<body>Hello wörld!</body>
</html>

HTML;

$response = React\Http\Message\Response::html($html);

This is a convenient shortcut method that returns the equivalent of this:

$response = new React\Http\Message\Response(
    React\Http\Message\Response::STATUS_OK,
    [
        'Content-Type' => 'text/html; charset=utf-8'
    ],
    $html
);

This method always returns a response with a 200 OK status code and
the appropriate Content-Type response header for the given HTTP source
string encoded in UTF-8 (Unicode). It’s generally recommended to end the
given plaintext string with a trailing newline.

If you want to use a different status code or custom HTTP response
headers, you can manipulate the returned response object using the
provided PSR-7 methods or directly instantiate a custom HTTP response
object using the Response constructor:

$response = React\Http\Message\Response::html(
    "<h1>Error</h1>\n<p>Invalid user name given.</p>\n"
)->withStatus(React\Http\Message\Response::STATUS_BAD_REQUEST);

json()

The static json(mixed $data): Response method can be used to
create a JSON response.

$response = React\Http\Message\Response::json(['name' => 'Alice']);

This is a convenient shortcut method that returns the equivalent of this:

$response = new React\Http\Message\Response(
    React\Http\Message\Response::STATUS_OK,
    [
        'Content-Type' => 'application/json'
    ],
    json_encode(
        ['name' => 'Alice'],
        JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRESERVE_ZERO_FRACTION
    ) . "\n"
);

This method always returns a response with a 200 OK status code and
the appropriate Content-Type response header for the given structured
data encoded as a JSON text.

The given structured data will be encoded as a JSON text. Any string
values in the data must be encoded in UTF-8 (Unicode). If the encoding
fails, this method will throw an InvalidArgumentException.

By default, the given structured data will be encoded with the flags as
shown above. This includes pretty printing (PHP 5.4+) and preserving
zero fractions for float values (PHP 5.6.6+) to ease debugging. It is
assumed any additional data overhead is usually compensated by using HTTP
response compression.

$response = React\Http\Message\Response::json(
    ['error' => 'Invalid user name given']
)->withStatus(React\Http\Message\Response::STATUS_BAD_REQUEST);

plaintext()

The static plaintext(string $text): Response method can be used to
create a plaintext response.

$response = React\Http\Message\Response::plaintext("Hello wörld!\n");

This is a convenient shortcut method that returns the equivalent of this:

$response = new React\Http\Message\Response(
    React\Http\Message\Response::STATUS_OK,
    [
        'Content-Type' => 'text/plain; charset=utf-8'
    ],
    "Hello wörld!\n"
);

This method always returns a response with a 200 OK status code and
the appropriate Content-Type response header for the given plaintext
string encoded in UTF-8 (Unicode). It’s generally recommended to end the
given plaintext string with a trailing newline.

$response = React\Http\Message\Response::plaintext(
    "Error: Invalid user name given.\n"
)->withStatus(React\Http\Message\Response::STATUS_BAD_REQUEST);

xml()

The static xml(string $xml): Response method can be used to
create an XML response.

$xml = <<<XML
<?xml version="1.0" encoding="utf-8"?>
<body>
    <greeting>Hello wörld!</greeting>
</body>

XML;

$response = React\Http\Message\Response::xml($xml);

This is a convenient shortcut method that returns the equivalent of this:

$response = new React\Http\Message\Response(
    React\Http\Message\Response::STATUS_OK,
    [
        'Content-Type' => 'application/xml'
    ],
    $xml
);

This method always returns a response with a 200 OK status code and
the appropriate Content-Type response header for the given XML source
string. It’s generally recommended to use UTF-8 (Unicode) and specify
this as part of the leading XML declaration and to end the given XML
source string with a trailing newline.

$response = React\Http\Message\Response::xml(
    "<error><message>Invalid user name given.</message></error>\n"
)->withStatus(React\Http\Message\Response::STATUS_BAD_REQUEST);

Request

The React\Http\Message\Request class can be used to
respresent an outgoing HTTP request message.

This class implements the
PSR-7 RequestInterface
which extends the
PSR-7 MessageInterface.

This is mostly used internally to represent each outgoing HTTP request
message for the HTTP client implementation. Likewise, you can also use this
class with other HTTP client implementations and for tests.

Internally, this implementation builds on top of a base class which is
considered an implementation detail that may change in the future.

ServerRequest

The React\Http\Message\ServerRequest class can be used to
respresent an incoming server request message.

This class implements the
PSR-7 ServerRequestInterface
which extends the
PSR-7 RequestInterface
which in turn extends the
PSR-7 MessageInterface.

This is mostly used internally to represent each incoming request message.
Likewise, you can also use this class in test cases to test how your web
application reacts to certain HTTP requests.

Internally, this implementation builds on top of a base class which is
considered an implementation detail that may change in the future.

Uri

The React\Http\Message\Uri class can be used to
respresent a URI (or URL).

This class implements the
PSR-7 UriInterface.

This is mostly used internally to represent the URI of each HTTP request
message for our HTTP client and server implementations. Likewise, you may
also use this class with other HTTP implementations and for tests.

ResponseException

The React\Http\Message\ResponseException is an Exception sub-class that will be used to reject
a request promise if the remote server returns a non-success status code
(anything but 2xx or 3xx).
You can control this behavior via the withRejectErrorResponse() method.

The getCode(): int method can be used to
return the HTTP response status code.

The getResponse(): ResponseInterface method can be used to
access its underlying response object.

React\Http\Middleware

StreamingRequestMiddleware

The React\Http\Middleware\StreamingRequestMiddleware can be used to
process incoming requests with a streaming request body (without buffering).

This allows you to process requests of any size without buffering the request
body in memory. Instead, it will represent the request body as a
ReadableStreamInterface
that emit chunks of incoming data as it is received:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    function (Psr\Http\Message\ServerRequestInterface $request) {
        $body = $request->getBody();
        assert($body instanceof Psr\Http\Message\StreamInterface);
        assert($body instanceof React\Stream\ReadableStreamInterface);

        return new React\Promise\Promise(function ($resolve) use ($body) {
            $bytes = 0;
            $body->on('data', function ($chunk) use (&$bytes) {
                $bytes += \count($chunk);
            });
            $body->on('close', function () use (&$bytes, $resolve) {
                $resolve(new React\Http\Message\Response(
                    React\Http\Message\Response::STATUS_OK,
                    [],
                    "Received $bytes bytes\n"
                ));
            });
        });
    }
);

See also streaming incoming request
for more details.

Additionally, this middleware can be used in combination with the
LimitConcurrentRequestsMiddleware and
RequestBodyBufferMiddleware (see below)
to explicitly configure the total number of requests that can be handled at
once:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(100), // 100 concurrent buffering handlers
    new React\Http\Middleware\RequestBodyBufferMiddleware(2 * 1024 * 1024), // 2 MiB per request
    new React\Http\Middleware\RequestBodyParserMiddleware(),
    $handler
);

Internally, this class is used as a “marker” to not trigger the default
request buffering behavior in the HttpServer. It does not implement any logic
on its own.

LimitConcurrentRequestsMiddleware

The React\Http\Middleware\LimitConcurrentRequestsMiddleware can be used to
limit how many next handlers can be executed concurrently.

If this middleware is invoked, it will check if the number of pending
handlers is below the allowed limit and then simply invoke the next handler
and it will return whatever the next handler returns (or throws).

If the number of pending handlers exceeds the allowed limit, the request will
be queued (and its streaming body will be paused) and it will return a pending
promise.
Once a pending handler returns (or throws), it will pick the oldest request
from this queue and invokes the next handler (and its streaming body will be
resumed).

The following example shows how this middleware can be used to ensure no more
than 10 handlers will be invoked at once:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(10),
    $handler
);

Similarly, this middleware is often used in combination with the
RequestBodyBufferMiddleware (see below)
to limit the total number of requests that can be buffered at once:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(100), // 100 concurrent buffering handlers
    new React\Http\Middleware\RequestBodyBufferMiddleware(2 * 1024 * 1024), // 2 MiB per request
    new React\Http\Middleware\RequestBodyParserMiddleware(),
    $handler
);

More sophisticated examples include limiting the total number of requests
that can be buffered at once and then ensure the actual request handler only
processes one request after another without any concurrency:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(100), // 100 concurrent buffering handlers
    new React\Http\Middleware\RequestBodyBufferMiddleware(2 * 1024 * 1024), // 2 MiB per request
    new React\Http\Middleware\RequestBodyParserMiddleware(),
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(1), // only execute 1 handler (no concurrency)
    $handler
);

RequestBodyBufferMiddleware

One of the built-in middleware is the React\Http\Middleware\RequestBodyBufferMiddleware which
can be used to buffer the whole incoming request body in memory.
This can be useful if full PSR-7 compatibility is needed for the request handler
and the default streaming request body handling is not needed.
The constructor accepts one optional argument, the maximum request body size.
When one isn’t provided it will use post_max_size (default 8 MiB) from PHP’s
configuration.
(Note that the value from your matching SAPI will be used, which is the CLI
configuration in most cases.)

Any incoming request that has a request body that exceeds this limit will be
accepted, but its request body will be discarded (empty request body).
This is done in order to avoid having to keep an incoming request with an
excessive size (for example, think of a 2 GB file upload) in memory.
This allows the next middleware handler to still handle this request, but it
will see an empty request body.
This is similar to PHP’s default behavior, where the body will not be parsed
if this limit is exceeded. However, unlike PHP’s default behavior, the raw
request body is not available via php://input.

The RequestBodyBufferMiddleware will buffer requests with bodies of known size
(i.e. with Content-Length header specified) as well as requests with bodies of
unknown size (i.e. with Transfer-Encoding: chunked header).

All requests will be buffered in memory until the request body end has
been reached and then call the next middleware handler with the complete,
buffered request.
Similarly, this will immediately invoke the next middleware handler for requests
that have an empty request body (such as a simple GET request) and requests
that are already buffered (such as due to another middleware).

Note that the given buffer size limit is applied to each request individually.
This means that if you allow a 2 MiB limit and then receive 1000 concurrent
requests, up to 2000 MiB may be allocated for these buffers alone.
As such, it’s highly recommended to use this along with the
LimitConcurrentRequestsMiddleware (see above) to limit
the total number of concurrent requests.

Usage:

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(100), // 100 concurrent buffering handlers
    new React\Http\Middleware\RequestBodyBufferMiddleware(16 * 1024 * 1024), // 16 MiB
    function (Psr\Http\Message\ServerRequestInterface $request) {
        // The body from $request->getBody() is now fully available without the need to stream it 
        return new React\Http\Message\Response(React\Http\Message\Response::STATUS_OK);
    },
);

RequestBodyParserMiddleware

The React\Http\Middleware\RequestBodyParserMiddleware takes a fully buffered request body
(generally from RequestBodyBufferMiddleware),
and parses the form values and file uploads from the incoming HTTP request body.

This middleware handler takes care of applying values from HTTP
requests that use Content-Type: application/x-www-form-urlencoded or
Content-Type: multipart/form-data to resemble PHP’s default superglobals
$_POST and $_FILES.
Instead of relying on these superglobals, you can use the
$request->getParsedBody() and $request->getUploadedFiles() methods
as defined by PSR-7.

Accordingly, each file upload will be represented as instance implementing the
PSR-7 UploadedFileInterface.
Due to its blocking nature, the moveTo() method is not available and throws
a RuntimeException instead.
You can use $contents = (string)$file->getStream(); to access the file
contents and persist this to your favorite data store.

$handler = function (Psr\Http\Message\ServerRequestInterface $request) {
    // If any, parsed form fields are now available from $request->getParsedBody()
    $body = $request->getParsedBody();
    $name = isset($body['name']) ? $body['name'] : 'unnamed';

    $files = $request->getUploadedFiles();
    $avatar = isset($files['avatar']) ? $files['avatar'] : null;
    if ($avatar instanceof Psr\Http\Message\UploadedFileInterface) {
        if ($avatar->getError() === UPLOAD_ERR_OK) {
            $uploaded = $avatar->getSize() . ' bytes';
        } elseif ($avatar->getError() === UPLOAD_ERR_INI_SIZE) {
            $uploaded = 'file too large';
        } else {
            $uploaded = 'with error';
        }
    } else {
        $uploaded = 'nothing';
    }

    return new React\Http\Message\Response(
        React\Http\Message\Response::STATUS_OK,
        array(
            'Content-Type' => 'text/plain'
        ),
        $name . ' uploaded ' . $uploaded
    );
};

$http = new React\Http\HttpServer(
    new React\Http\Middleware\StreamingRequestMiddleware(),
    new React\Http\Middleware\LimitConcurrentRequestsMiddleware(100), // 100 concurrent buffering handlers
    new React\Http\Middleware\RequestBodyBufferMiddleware(16 * 1024 * 1024), // 16 MiB
    new React\Http\Middleware\RequestBodyParserMiddleware(),
    $handler
);

See also form upload server example for more details.

By default, this middleware respects the
upload_max_filesize
(default 2M) ini setting.
Files that exceed this limit will be rejected with an UPLOAD_ERR_INI_SIZE error.
You can control the maximum filesize for each individual file upload by
explicitly passing the maximum filesize in bytes as the first parameter to the
constructor like this:

new React\Http\Middleware\RequestBodyParserMiddleware(8 * 1024 * 1024); // 8 MiB limit per file

By default, this middleware respects the
file_uploads
(default 1) and
max_file_uploads
(default 20) ini settings.
These settings control if any and how many files can be uploaded in a single request.
If you upload more files in a single request, additional files will be ignored
and the getUploadedFiles() method returns a truncated array.
Note that upload fields left blank on submission do not count towards this limit.
You can control the maximum number of file uploads per request by explicitly
passing the second parameter to the constructor like this:

new React\Http\Middleware\RequestBodyParserMiddleware(10 * 1024, 100); // 100 files with 10 KiB each

Note that this middleware handler simply parses everything that is already
buffered in the request body.
It is imperative that the request body is buffered by a prior middleware
handler as given in the example above.
This previous middleware handler is also responsible for rejecting incoming
requests that exceed allowed message sizes (such as big file uploads).
The RequestBodyBufferMiddleware used above
simply discards excessive request bodies, resulting in an empty body.
If you use this middleware without buffering first, it will try to parse an
empty (streaming) body and may thus assume an empty data structure.
See also RequestBodyBufferMiddleware for
more details.

PHP’s MAX_FILE_SIZE hidden field is respected by this middleware.
Files that exceed this limit will be rejected with an UPLOAD_ERR_FORM_SIZE error.

This middleware respects the
max_input_vars
(default 1000) and
max_input_nesting_level
(default 64) ini settings.

Note that this middleware ignores the
enable_post_data_reading
(default 1) ini setting because it makes little sense to respect here and
is left up to higher-level implementations.
If you want to respect this setting, you have to check its value and
effectively avoid using this middleware entirely.

Install

The recommended way to install this library is through Composer.
New to Composer?

This project follows SemVer.
This will install the latest supported version:

composer require react/http:^1.10

See also the CHANGELOG for details about version upgrades.

This project aims to run on any platform and thus does not require any PHP
extensions and supports running on legacy PHP 5.3 through current PHP 8+ and
HHVM.
It’s highly recommended to use the latest supported PHP version for this project.

Tests

To run the test suite, you first need to clone this repo and then install all
dependencies through Composer:

composer install

To run the test suite, go to the project root and run:

vendor/bin/phpunit

The test suite also contains a number of functional integration tests that rely
on a stable internet connection.
If you do not want to run these, they can simply be skipped like this:

vendor/bin/phpunit --exclude-group internet

License

MIT, see LICENSE file.