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<?php
namespace Guzzle\Http;
use Guzzle\Common\Event;
use Guzzle\Http\Exception\BadResponseException;
use Guzzle\Http\Url;
use Guzzle\Http\Message\Response;
use Guzzle\Http\Message\RequestInterface;
use Guzzle\Http\Message\RequestFactory;
use Guzzle\Http\Message\EntityEnclosingRequestInterface;
use Guzzle\Http\Exception\TooManyRedirectsException;
use Guzzle\Http\Exception\CouldNotRewindStreamException;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
/**
* Plugin to implement HTTP redirects. Can redirect like a web browser or using strict RFC 2616 compliance
*/
class RedirectPlugin implements EventSubscriberInterface
{
const REDIRECT_COUNT = 'redirect.count';
const MAX_REDIRECTS = 'redirect.max';
const STRICT_REDIRECTS = 'redirect.strict';
const PARENT_REQUEST = 'redirect.parent_request';
const DISABLE = 'redirect.disable';
/**
* @var int Default number of redirects allowed when no setting is supplied by a request
*/
protected $defaultMaxRedirects = 5;
public static function getSubscribedEvents()
{
return array(
'request.sent' => array('onRequestSent', 100),
'request.clone' => 'cleanupRequest',
'request.before_send' => 'cleanupRequest'
);
}
/**
* Clean up the parameters of a request when it is cloned
*
* @param Event $event Event emitted
*/
public function cleanupRequest(Event $event)
{
$params = $event['request']->getParams();
unset($params[self::REDIRECT_COUNT]);
unset($params[self::PARENT_REQUEST]);
}
/**
* Called when a request receives a redirect response
*
* @param Event $event Event emitted
*/
public function onRequestSent(Event $event)
{
$response = $event['response'];
$request = $event['request'];
// Only act on redirect requests with Location headers
if (!$response || $request->getParams()->get(self::DISABLE)) {
return;
}
// Trace the original request based on parameter history
$original = $this->getOriginalRequest($request);
// Terminating condition to set the effective response on the original request
if (!$response->isRedirect() || !$response->hasHeader('Location')) {
if ($request !== $original) {
// This is a terminating redirect response, so set it on the original request
$response->getParams()->set(self::REDIRECT_COUNT, $original->getParams()->get(self::REDIRECT_COUNT));
$original->setResponse($response);
$response->setEffectiveUrl($request->getUrl());
}
return;
}
$this->sendRedirectRequest($original, $request, $response);
}
/**
* Get the original request that initiated a series of redirects
*
* @param RequestInterface $request Request to get the original request from
*
* @return RequestInterface
*/
protected function getOriginalRequest(RequestInterface $request)
{
$original = $request;
// The number of redirects is held on the original request, so determine which request that is
while ($parent = $original->getParams()->get(self::PARENT_REQUEST)) {
$original = $parent;
}
return $original;
}
/**
* Create a redirect request for a specific request object
*
* Takes into account strict RFC compliant redirection (e.g. redirect POST with POST) vs doing what most clients do
* (e.g. redirect POST with GET).
*
* @param RequestInterface $request Request being redirected
* @param RequestInterface $original Original request
* @param int $statusCode Status code of the redirect
* @param string $location Location header of the redirect
*
* @return RequestInterface Returns a new redirect request
* @throws CouldNotRewindStreamException If the body needs to be rewound but cannot
*/
protected function createRedirectRequest(
RequestInterface $request,
$statusCode,
$location,
RequestInterface $original
) {
$redirectRequest = null;
$strict = $original->getParams()->get(self::STRICT_REDIRECTS);
// Switch method to GET for 303 redirects. 301 and 302 redirects also switch to GET unless we are forcing RFC
// compliance to emulate what most browsers do. NOTE: IE only switches methods on 301/302 when coming from a POST.
if ($request instanceof EntityEnclosingRequestInterface && ($statusCode == 303 || (!$strict && $statusCode <= 302))) {
$redirectRequest = RequestFactory::getInstance()->cloneRequestWithMethod($request, 'GET');
} else {
$redirectRequest = clone $request;
}
$redirectRequest->setIsRedirect(true);
// Always use the same response body when redirecting
$redirectRequest->setResponseBody($request->getResponseBody());
$location = Url::factory($location);
// If the location is not absolute, then combine it with the original URL
if (!$location->isAbsolute()) {
$originalUrl = $redirectRequest->getUrl(true);
// Remove query string parameters and just take what is present on the redirect Location header
$originalUrl->getQuery()->clear();
$location = $originalUrl->combine((string) $location, true);
}
$redirectRequest->setUrl($location);
// Add the parent request to the request before it sends (make sure it's before the onRequestClone event too)
$redirectRequest->getEventDispatcher()->addListener(
'request.before_send',
$func = function ($e) use (&$func, $request, $redirectRequest) {
$redirectRequest->getEventDispatcher()->removeListener('request.before_send', $func);
$e['request']->getParams()->set(RedirectPlugin::PARENT_REQUEST, $request);
}
);
// Rewind the entity body of the request if needed
if ($redirectRequest instanceof EntityEnclosingRequestInterface && $redirectRequest->getBody()) {
$body = $redirectRequest->getBody();
// Only rewind the body if some of it has been read already, and throw an exception if the rewind fails
if ($body->ftell() && !$body->rewind()) {
throw new CouldNotRewindStreamException(
'Unable to rewind the non-seekable entity body of the request after redirecting. cURL probably '
. 'sent part of body before the redirect occurred. Try adding acustom rewind function using on the '
. 'entity body of the request using setRewindFunction().'
);
}
}
return $redirectRequest;
}
/**
* Prepare the request for redirection and enforce the maximum number of allowed redirects per client
*
* @param RequestInterface $original Original request
* @param RequestInterface $request Request to prepare and validate
* @param Response $response The current response
*
* @return RequestInterface
*/
protected function prepareRedirection(RequestInterface $original, RequestInterface $request, Response $response)
{
$params = $original->getParams();
// This is a new redirect, so increment the redirect counter
$current = $params[self::REDIRECT_COUNT] + 1;
$params[self::REDIRECT_COUNT] = $current;
// Use a provided maximum value or default to a max redirect count of 5
$max = isset($params[self::MAX_REDIRECTS]) ? $params[self::MAX_REDIRECTS] : $this->defaultMaxRedirects;
// Throw an exception if the redirect count is exceeded
if ($current > $max) {
$this->throwTooManyRedirectsException($original, $max);
return false;
} else {
// Create a redirect request based on the redirect rules set on the request
return $this->createRedirectRequest(
$request,
$response->getStatusCode(),
trim($response->getLocation()),
$original
);
}
}
/**
* Send a redirect request and handle any errors
*
* @param RequestInterface $original The originating request
* @param RequestInterface $request The current request being redirected
* @param Response $response The response of the current request
*
* @throws BadResponseException|\Exception
*/
protected function sendRedirectRequest(RequestInterface $original, RequestInterface $request, Response $response)
{
// Validate and create a redirect request based on the original request and current response
if ($redirectRequest = $this->prepareRedirection($original, $request, $response)) {
try {
$redirectRequest->send();
} catch (BadResponseException $e) {
$e->getResponse();
if (!$e->getResponse()) {
throw $e;
}
}
}
}
/**
* Throw a too many redirects exception for a request
*
* @param RequestInterface $original Request
* @param int $max Max allowed redirects
*
* @throws TooManyRedirectsException when too many redirects have been issued
*/
protected function throwTooManyRedirectsException(RequestInterface $original, $max)
{
$original->getEventDispatcher()->addListener(
'request.complete',
$func = function ($e) use (&$func, $original, $max) {
$original->getEventDispatcher()->removeListener('request.complete', $func);
$str = "{$max} redirects were issued for this request:\n" . $e['request']->getRawHeaders();
throw new TooManyRedirectsException($str);
}
);
}
}