Http Component
Event-driven, streaming plaintext HTTP and secure HTTPS server for ReactPHP
Table of Contents
Quickstart example
This is an HTTP server which responds with Hello World to every request.
$loop = React\EventLoop\Factory::create();
$socket = new React\Socket\Server(8080, $loop);
$http = new Server($socket, function (ServerRequestInterface $request) {
return new Response(
200,
array('Content-Type' => 'text/plain'),
"Hello World!\n"
);
});
$loop->run();See also the examples.
Usage
Server
The Server class is responsible for handling incoming connections and then
processing each incoming HTTP request.
It attaches itself to an instance of React\Socket\ServerInterface which
emits underlying streaming connections in order to then parse incoming data
as HTTP.
For each request, it executes the callback function passed to the constructor with the respective request and response objects:
$socket = new React\Socket\Server(8080, $loop);
$http = new Server($socket, function (ServerRequestInterface $request) {
return new Response(
200,
array('Content-Type' => 'text/plain'),
"Hello World!\n"
);
});See also the first example for more details.
Similarly, you can also attach this to a
React\Socket\SecureServer
in order to start a secure HTTPS server like this:
$socket = new React\Socket\Server(8080, $loop);
$socket = new React\Socket\SecureServer($socket, $loop, array(
'local_cert' => __DIR__ . '/localhost.pem'
));
$http = new Server($socket, function (ServerRequestInterface $request) {
return new Response(
200,
array('Content-Type' => 'text/plain'),
"Hello World!\n"
);
});See also example #11 for more details.
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 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.
The Response still needs to be created as described in the
examples above.
See also request and response for more details (e.g. the request data body).
The Server 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 in the request header, it will
emit an error event, send an HTTP error response to the client and
close the connection:
$http->on('error', function (Exception $e) {
echo 'Error: ' . $e->getMessage() . PHP_EOL;
});The server will also emit an error event if you return an invalid
type in the callback function or have a unhandled Exception.
If your callback function throws an exception,
the Server will emit a RuntimeException and add the thrown exception
as previous:
$http->on('error', function (Exception $e) {
echo 'Error: ' . $e->getMessage() . PHP_EOL;
if ($e->getPrevious() !== null) {
$previousException = $e->getPrevious();
echo $previousException->getMessage() . PHP_EOL;
}
});Note that the request object can also emit an error. Check out request for more details.
Request
An seen above, the Server class is responsible for handling incoming
connections and then processing each incoming HTTP request.
The request object will be processed once the request headers have 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.
$http = new Server($socket, function (ServerRequestInterface $request) {
$body = "The method of the request is: " . $request->getMethod();
$body .= "The requested path is: " . $request->getUri()->getPath();
return new Response(
200,
array('Content-Type' => 'text/plain'),
$body
);
});The getServerParams(): mixed[] method can be used to
get server-side parameters similar to the $_SERVER variable.
The following parameters are currently available:
REMOTE_ADDRThe IP address of the request senderREMOTE_PORTPort of the request senderSERVER_ADDRThe IP address of the serverSERVER_PORTThe port of the serverREQUEST_TIMEUnix timestamp when the complete request header has been received, as integer similar totime()REQUEST_TIME_FLOATUnix timestamp when the complete request header has been received, as float similar tomicrotime(true)HTTPSSet to 'on' if the request used HTTPS, otherwise it won't be set
$http = new Server($socket, function (ServerRequestInterface $request) {
$body = "Your IP is: " . $request->getServerParams()['REMOTE_ADDR'];
return new Response(
200,
array('Content-Type' => 'text/plain'),
$body
);
});See also example #2.
The getQueryParams(): array method can be used to get the query parameters
similiar to the $_GET variable.
$http = new Server($socket, function (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 new Response(
200,
array('Content-Type' => 'text/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).
See also example #3.
For more details about the request object, check out the documentation of PSR-7 ServerRequestInterface and PSR-7 RequestInterface.
Currently the uploaded files are not added by the
Server, but you can add these parameters by yourself using the given methods. The next versions of this project will cover these features.
Note that 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. 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() method can be used to access the request body stream.
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 the 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().
Instead, you should use the ReactPHP ReadableStreamInterface which
gives you access to the incoming request body as the individual chunks arrive:
$http = new Server($socket, function (ServerRequestInterface $request) {
return new Promise(function ($resolve, $reject) use ($request) {
$contentLength = 0;
$request->getBody()->on('data', function ($data) use (&$contentLength) {
$contentLength += strlen($data);
});
$request->getBody()->on('end', function () use ($resolve, &$contentLength){
$response = new Response(
200,
array('Content-Type' => 'text/plain'),
"The length of the submitted request body is: " . $contentLength
);
$resolve($response);
});
// an error occures e.g. on invalid chunked encoded data or an unexpected 'end' event
$request->getBody()->on('error', function (\Exception $exception) use ($resolve, &$contentLength) {
$response = new Response(
400,
array('Content-Type' => 'text/plain'),
"An error occured while reading at length: " . $contentLength
);
$resolve($response);
});
});
});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 example #4 for more details.
The data event will be emitted whenever new data is available on the request
body stream.
The server automatically takes care of decoding chunked transfer encoding
and will only emit the actual payload as data.
In this case, the Transfer-Encoding header will be removed.
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
chunked data or the connection closes before the complete request stream has
been received.
The server will automatically pause() the connection 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 if you only want to know the request
body size.
This method returns the complete size of the request body 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).
Note that this value may be null if the request body size is unknown in
advance because the request message uses chunked transfer encoding.
$http = new Server($socket, function (ServerRequestInterface $request) {
$size = $request->getBody()->getSize();
if ($size === null) {
$body = 'The request does not contain an explicit length.';
$body .= 'This server does not accept chunked transfer encoding.';
return new Response(
411,
array('Content-Type' => 'text/plain'),
$body
);
}
return new Response(
200,
array('Content-Type' => 'text/plain'),
"Request body size: " . $size . " bytes\n"
);
});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 a 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
CONNECTmethod 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 theHostheader value (such as removing default ports) and the request-target MUST take precendence when forwarding. 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 the message body of the request and response for tunneled application data. This implies that that a2xx(Successful) response to aCONNECTrequest can in fact use a streaming response body for the tunneled application data. See also example #21 for more details.
The getCookieParams(): string[] method can be used to
get all cookies sent with the current request.
$http = new Server($socket, function (ServerRequestInterface $request) {
$key = 'react\php';
if (isset($request->getCookieParams()[$key])) {
$body = "Your cookie value is: " . $request->getCookieParams()[$key];
return new Response(
200,
array('Content-Type' => 'text/plain'),
$body
);
}
return new Response(
200,
array(
'Content-Type' => 'text/plain',
'Set-Cookie' => urlencode($key) . '=' . urlencode('test;more')
),
"Your cookie has been set."
);
});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 example #6 for more details.
Response
The callback function passed to the constructor of the Server
is responsible for processing the request and returning a response,
which will be delivered to the client.
This function MUST return an instance imlementing
PSR-7 ResponseInterface
object or a
ReactPHP Promise
which will resolve a PSR-7 ResponseInterface object.
You will find a Response class
which implements the PSR-7 ResponseInterface in this project.
We use instantiation of this class in our projects,
but feel free to use any implemantation of the
PSR-7 ResponseInterface you prefer.
$http = new Server($socket, function (ServerRequestInterface $request) {
return new Response(
200,
array('Content-Type' => 'text/plain'),
"Hello World!\n"
);
});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:
$server = new \React\Http\Server($socket, function (ServerRequestInterface $request) use ($loop) {
return new Promise(function ($resolve, $reject) use ($request, $loop) {
$loop->addTimer(1.5, function() use ($loop, $resolve) {
$response = new Response(
200,
array('Content-Type' => 'text/plain'),
"Hello world"
);
$resolve($response);
});
});
});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.
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 likely
only support strings.
$server = new Server($socket, function (ServerRequestInterface $request) use ($loop) {
$stream = new ThroughStream();
$timer = $loop->addPeriodicTimer(0.5, function () use ($stream) {
$stream->emit('data', array(microtime(true) . PHP_EOL));
});
$loop->addTimer(5, function() use ($loop, $timer, $stream) {
$loop->cancelTimer($timer);
$stream->emit('end');
});
return new Response(200, 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 response body is a string, a Content-Length header will be added
automatically.
If the response body is a ReactPHP ReadableStreamInterface and you do not
specify a Content-Length header, HTTP/1.1 responses will automatically use
chunked transfer encoding and send the respective header
(Transfer-Encoding: chunked) automatically.
The server is responsible for handling Transfer-Encoding, so you SHOULD NOT
pass this header yourself.
If you know the length of your stream body, you MAY specify it like this instead:
$stream = new ThroughStream()
$server = new Server($socket, function (ServerRequestInterface $request) use ($loop, $stream) {
return new Response(
200,
array(
'Content-Length' => '5',
'Content-Type' => 'text/plain',
),
$stream
);
});An invalid return value or an unhandled Exception in the code of the callback
function, will result in an 500 Internal Server Error message.
Make sure to catch Exceptions to create own response messages.
After the return in the callback function the response will be processed by the Server.
The Server will add the protocol version of the request, so you don't have to.
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.
The
CONNECTmethod is useful in a tunneling setup (HTTPS proxy) and not something most 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 the message body of the request and response for tunneled application data. This implies that that a2xx(Successful) response to aCONNECTrequest can in fact use a streaming response body for the tunneled application data. See also example #22 for more details.
A Date header will be automatically added with the system date and time if none is given.
You can add a custom Date header yourself like this:
$server = new Server($socket, function (ServerRequestInterface $request) {
return new Response(200, array('Date' => date('D, d M Y H:i:s T')));
});If you don't have a appropriate clock to rely on, you should unset this header with an empty string:
$server = new Server($socket, function (ServerRequestInterface $request) {
return new Response(200, array('Date' => ''));
});Note that it will automatically assume a X-Powered-By: react/alpha header
unless your specify a custom X-Powered-By header yourself:
$server = new Server($socket, function (ServerRequestInterface $request) {
return new Response(200, array('X-Powered-By' => 'PHP 3'));
});If you do not want to send this header at all, you can use an empty string as value like this:
$server = new Server($socket, function (ServerRequestInterface $request) {
return new Response(200, array('X-Powered-By' => ''));
});Note that persistent connections (Connection: keep-alive) are currently
not supported.
As such, HTTP/1.1 response messages will automatically include a
Connection: close header, irrespective of what header values are
passed explicitly.
Install
The recommended way to install this library is through Composer. New to Composer?
This will install the latest supported version:
$ composer require react/http:^0.6More details about version upgrades can be found in the CHANGELOG.
Tests
To run the test suite, you first need to clone this repo and then install all dependencies through Composer:
$ composer installTo run the test suite, go to the project root and run:
$ php vendor/bin/phpunitLicense
MIT, see LICENSE file.
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