<?php
namespace GuzzleHttp;
use GuzzleHttp\Cookie\CookieJarInterface;
use GuzzleHttp\Exception\RequestException;
use GuzzleHttp\Promise\RejectedPromise;
use GuzzleHttp\Psr7;
use Psr\Http\Message\ResponseInterface;
use Psr\Log\LoggerInterface;
use Psr\Log\LogLevel;
/**
* Functions used to create and wrap handlers with handler middleware.
*/
final class Middleware
{
/**
* Middleware that adds cookies to requests.
*
* The options array must be set to a CookieJarInterface in order to use
* cookies. This is typically handled for you by a client.
*
* @return callable Returns a function that accepts the next handler.
*/
public static function cookies()
{
return function (callable $handler) {
return function ($request, array $options) use ($handler) {
if (empty($options['cookies'])) {
return $handler($request, $options);
} elseif (!($options['cookies'] instanceof CookieJarInterface)) {
throw new \InvalidArgumentException('cookies must be an instance of GuzzleHttp\Cookie\CookieJarInterface');
}
$cookieJar = $options['cookies'];
$request = $cookieJar->withCookieHeader($request);
return $handler($request, $options)
->then(
function ($response) use ($cookieJar, $request) {
$cookieJar->extractCookies($request, $response);
return $response;
}
);
};
};
}
/**
* Middleware that throws exceptions for 4xx or 5xx responses when the
* "http_error" request option is set to true.
*
* @return callable Returns a function that accepts the next handler.
*/
public static function httpErrors()
{
return function (callable $handler) {
return function ($request, array $options) use ($handler) {
if (empty($options['http_errors'])) {
return $handler($request, $options);
}
return $handler($request, $options)->then(
function (ResponseInterface $response) use ($request, $handler) {
$code = $response->getStatusCode();
if ($code < 400) {
return $response;
}
throw RequestException::create($request, $response);
}
);
};
};
}
/**
* Middleware that pushes history data to an ArrayAccess container.
*
* @param array|\ArrayAccess $container Container to hold the history (by reference).
*
* @return callable Returns a function that accepts the next handler.
* @throws \InvalidArgumentException if container is not an array or ArrayAccess.
*/
public static function history(&$container)
{
if (!is_array($container) && !$container instanceof \ArrayAccess) {
throw new \InvalidArgumentException('history container must be an array or object implementing ArrayAccess');
}
return function (callable $handler) use (&$container) {
return function ($request, array $options) use ($handler, &$container) {
return $handler($request, $options)->then(
function ($value) use ($request, &$container, $options) {
$container[] = [
'request' => $request,
'response' => $value,
'error' => null,
'options' => $options
];
return $value;
},
function ($reason) use ($request, &$container, $options) {
$container[] = [
'request' => $request,
'response' => null,
'error' => $reason,
'options' => $options
];
return \GuzzleHttp\Promise\rejection_for($reason);
}
);
};
};
}
/**
* Middleware that invokes a callback before and after sending a request.
*
* The provided listener cannot modify or alter the response. It simply
* "taps" into the chain to be notified before returning the promise. The
* before listener accepts a request and options array, and the after
* listener accepts a request, options array, and response promise.
*
* @param callable $before Function to invoke before forwarding the request.
* @param callable $after Function invoked after forwarding.
*
* @return callable Returns a function that accepts the next handler.
*/
public static function tap(callable $before = null, callable $after = null)
{
return function (callable $handler) use ($before, $after) {
return function ($request, array $options) use ($handler, $before, $after) {
if ($before) {
$before($request, $options);
}
$response = $handler($request, $options);
if ($after) {
$after($request, $options, $response);
}
return $response;
};
};
}
/**
* Middleware that handles request redirects.
*
* @return callable Returns a function that accepts the next handler.
*/
public static function redirect()
{
return function (callable $handler) {
return new RedirectMiddleware($handler);
};
}
/**
* Middleware that retries requests based on the boolean result of
* invoking the provided "decider" function.
*
* If no delay function is provided, a simple implementation of exponential
* backoff will be utilized.
*
* @param callable $decider Function that accepts the number of retries,
* a request, [response], and [exception] and
* returns true if the request is to be retried.
* @param callable $delay Function that accepts the number of retries and
* returns the number of milliseconds to delay.
*
* @return callable Returns a function that accepts the next handler.
*/
public static function retry(callable $decider, callable $delay = null)
{
return function (callable $handler) use ($decider, $delay) {
return new RetryMiddleware($decider, $handler, $delay);
};
}
/**
* Middleware that logs requests, responses, and errors using a message
* formatter.
*
* @param LoggerInterface $logger Logs messages.
* @param MessageFormatter $formatter Formatter used to create message strings.
* @param string $logLevel Level at which to log requests.
*
* @return callable Returns a function that accepts the next handler.
*/
public static function log(LoggerInterface $logger, MessageFormatter $formatter, $logLevel = LogLevel::INFO)
{
return function (callable $handler) use ($logger, $formatter, $logLevel) {
return function ($request, array $options) use ($handler, $logger, $formatter, $logLevel) {
return $handler($request, $options)->then(
function ($response) use ($logger, $request, $formatter, $logLevel) {
$message = $formatter->format($request, $response);
$logger->log($logLevel, $message);
return $response;
},
function ($reason) use ($logger, $request, $formatter) {
$response = $reason instanceof RequestException
? $reason->getResponse()
: null;
$message = $formatter->format($request, $response, $reason);
$logger->notice($message);
return \GuzzleHttp\Promise\rejection_for($reason);
}
);
};
};
}
/**
* This middleware adds a default content-type if possible, a default
* content-length or transfer-encoding header, and the expect header.
*
* @return callable
*/
public static function prepareBody()
{
return function (callable $handler) {
return new PrepareBodyMiddleware($handler);
};
}
/**
* Middleware that applies a map function to the request before passing to
* the next handler.
*
* @param callable $fn Function that accepts a RequestInterface and returns
* a RequestInterface.
* @return callable
*/
public static function mapRequest(callable $fn)
{
return function (callable $handler) use ($fn) {
return function ($request, array $options) use ($handler, $fn) {
return $handler($fn($request), $options);
};
};
}
/**
* Middleware that applies a map function to the resolved promise's
* response.
*
* @param callable $fn Function that accepts a ResponseInterface and
* returns a ResponseInterface.
* @return callable
*/
public static function mapResponse(callable $fn)
{
return function (callable $handler) use ($fn) {
return function ($request, array $options) use ($handler, $fn) {
return $handler($request, $options)->then($fn);
};
};
}
}