1Guzzle Upgrade Guide
2====================
3
46.0 to 7.0
5----------
6
7In order to take advantage of the new features of PHP, Guzzle dropped the support
8of PHP 5. The minimum supported PHP version is now PHP 7.2. Type hints and return
9types for functions and methods have been added wherever possible.
10
11Please make sure:
12- You are calling a function or a method with the correct type.
13- If you extend a class of Guzzle; update all signatures on methods you override.
14
15#### Other backwards compatibility breaking changes
16
17- Class `GuzzleHttp\UriTemplate` is removed.
18- Class `GuzzleHttp\Exception\SeekException` is removed.
19- Classes `GuzzleHttp\Exception\BadResponseException`, `GuzzleHttp\Exception\ClientException`,
20  `GuzzleHttp\Exception\ServerException` can no longer be initialized with an empty
21  Response as argument.
22- Class `GuzzleHttp\Exception\ConnectException` now extends `GuzzleHttp\Exception\TransferException`
23  instead of `GuzzleHttp\Exception\RequestException`.
24- Function `GuzzleHttp\Exception\ConnectException::getResponse()` is removed.
25- Function `GuzzleHttp\Exception\ConnectException::hasResponse()` is removed.
26- Constant `GuzzleHttp\ClientInterface::VERSION` is removed. Added `GuzzleHttp\ClientInterface::MAJOR_VERSION` instead.
27- Function `GuzzleHttp\Exception\RequestException::getResponseBodySummary` is removed.
28  Use `\GuzzleHttp\Psr7\get_message_body_summary` as an alternative.
29- Function `GuzzleHttp\Cookie\CookieJar::getCookieValue` is removed.
30- Request option `exception` is removed. Please use `http_errors`.
31- Request option `save_to` is removed. Please use `sink`.
32- Pool option `pool_size` is removed. Please use `concurrency`.
33- We now look for environment variables in the `$_SERVER` super global, due to thread safety issues with `getenv`. We continue to fallback to `getenv` in CLI environments, for maximum compatibility.
34- The `get`, `head`, `put`, `post`, `patch`, `delete`, `getAsync`, `headAsync`, `putAsync`, `postAsync`, `patchAsync`, and `deleteAsync` methods are now implemented as genuine methods on `GuzzleHttp\Client`, with strong typing. The original `__call` implementation remains unchanged for now, for maximum backwards compatibility, but won't be invoked under normal operation.
35- The `log` middleware will log the errors with level `error` instead of `notice`
36- Support for international domain names (IDN) is now disabled by default, and enabling it requires installing ext-intl, linked against a modern version of the C library (ICU 4.6 or higher).
37
38#### Native functions calls
39
40All internal native functions calls of Guzzle are now prefixed with a slash. This
41change makes it impossible for method overloading by other libraries or applications.
42Example:
43
44```php
45// Before:
46curl_version();
47
48// After:
49\curl_version();
50```
51
52For the full diff you can check [here](https://github.com/guzzle/guzzle/compare/6.5.4..master).
53
545.0 to 6.0
55----------
56
57Guzzle now uses [PSR-7](https://www.php-fig.org/psr/psr-7/) for HTTP messages.
58Due to the fact that these messages are immutable, this prompted a refactoring
59of Guzzle to use a middleware based system rather than an event system. Any
60HTTP message interaction (e.g., `GuzzleHttp\Message\Request`) need to be
61updated to work with the new immutable PSR-7 request and response objects. Any
62event listeners or subscribers need to be updated to become middleware
63functions that wrap handlers (or are injected into a
64`GuzzleHttp\HandlerStack`).
65
66- Removed `GuzzleHttp\BatchResults`
67- Removed `GuzzleHttp\Collection`
68- Removed `GuzzleHttp\HasDataTrait`
69- Removed `GuzzleHttp\ToArrayInterface`
70- The `guzzlehttp/streams` dependency has been removed. Stream functionality
71  is now present in the `GuzzleHttp\Psr7` namespace provided by the
72  `guzzlehttp/psr7` package.
73- Guzzle no longer uses ReactPHP promises and now uses the
74  `guzzlehttp/promises` library. We use a custom promise library for three
75  significant reasons:
76  1. React promises (at the time of writing this) are recursive. Promise
77     chaining and promise resolution will eventually blow the stack. Guzzle
78     promises are not recursive as they use a sort of trampolining technique.
79     Note: there has been movement in the React project to modify promises to
80     no longer utilize recursion.
81  2. Guzzle needs to have the ability to synchronously block on a promise to
82     wait for a result. Guzzle promises allows this functionality (and does
83     not require the use of recursion).
84  3. Because we need to be able to wait on a result, doing so using React
85     promises requires wrapping react promises with RingPHP futures. This
86     overhead is no longer needed, reducing stack sizes, reducing complexity,
87     and improving performance.
88- `GuzzleHttp\Mimetypes` has been moved to a function in
89  `GuzzleHttp\Psr7\mimetype_from_extension` and
90  `GuzzleHttp\Psr7\mimetype_from_filename`.
91- `GuzzleHttp\Query` and `GuzzleHttp\QueryParser` have been removed. Query
92  strings must now be passed into request objects as strings, or provided to
93  the `query` request option when creating requests with clients. The `query`
94  option uses PHP's `http_build_query` to convert an array to a string. If you
95  need a different serialization technique, you will need to pass the query
96  string in as a string. There are a couple helper functions that will make
97  working with query strings easier: `GuzzleHttp\Psr7\parse_query` and
98  `GuzzleHttp\Psr7\build_query`.
99- Guzzle no longer has a dependency on RingPHP. Due to the use of a middleware
100  system based on PSR-7, using RingPHP and it's middleware system as well adds
101  more complexity than the benefits it provides. All HTTP handlers that were
102  present in RingPHP have been modified to work directly with PSR-7 messages
103  and placed in the `GuzzleHttp\Handler` namespace. This significantly reduces
104  complexity in Guzzle, removes a dependency, and improves performance. RingPHP
105  will be maintained for Guzzle 5 support, but will no longer be a part of
106  Guzzle 6.
107- As Guzzle now uses a middleware based systems the event system and RingPHP
108  integration has been removed. Note: while the event system has been removed,
109  it is possible to add your own type of event system that is powered by the
110  middleware system.
111  - Removed the `Event` namespace.
112  - Removed the `Subscriber` namespace.
113  - Removed `Transaction` class
114  - Removed `RequestFsm`
115  - Removed `RingBridge`
116  - `GuzzleHttp\Subscriber\Cookie` is now provided by
117    `GuzzleHttp\Middleware::cookies`
118  - `GuzzleHttp\Subscriber\HttpError` is now provided by
119    `GuzzleHttp\Middleware::httpError`
120  - `GuzzleHttp\Subscriber\History` is now provided by
121    `GuzzleHttp\Middleware::history`
122  - `GuzzleHttp\Subscriber\Mock` is now provided by
123    `GuzzleHttp\Handler\MockHandler`
124  - `GuzzleHttp\Subscriber\Prepare` is now provided by
125    `GuzzleHttp\PrepareBodyMiddleware`
126  - `GuzzleHttp\Subscriber\Redirect` is now provided by
127    `GuzzleHttp\RedirectMiddleware`
128- Guzzle now uses `Psr\Http\Message\UriInterface` (implements in
129  `GuzzleHttp\Psr7\Uri`) for URI support. `GuzzleHttp\Url` is now gone.
130- Static functions in `GuzzleHttp\Utils` have been moved to namespaced
131  functions under the `GuzzleHttp` namespace. This requires either a Composer
132  based autoloader or you to include functions.php.
133- `GuzzleHttp\ClientInterface::getDefaultOption` has been renamed to
134  `GuzzleHttp\ClientInterface::getConfig`.
135- `GuzzleHttp\ClientInterface::setDefaultOption` has been removed.
136- The `json` and `xml` methods of response objects has been removed. With the
137  migration to strictly adhering to PSR-7 as the interface for Guzzle messages,
138  adding methods to message interfaces would actually require Guzzle messages
139  to extend from PSR-7 messages rather then work with them directly.
140
141## Migrating to middleware
142
143The change to PSR-7 unfortunately required significant refactoring to Guzzle
144due to the fact that PSR-7 messages are immutable. Guzzle 5 relied on an event
145system from plugins. The event system relied on mutability of HTTP messages and
146side effects in order to work. With immutable messages, you have to change your
147workflow to become more about either returning a value (e.g., functional
148middlewares) or setting a value on an object. Guzzle v6 has chosen the
149functional middleware approach.
150
151Instead of using the event system to listen for things like the `before` event,
152you now create a stack based middleware function that intercepts a request on
153the way in and the promise of the response on the way out. This is a much
154simpler and more predictable approach than the event system and works nicely
155with PSR-7 middleware. Due to the use of promises, the middleware system is
156also asynchronous.
157
158v5:
159
160```php
161use GuzzleHttp\Event\BeforeEvent;
162$client = new GuzzleHttp\Client();
163// Get the emitter and listen to the before event.
164$client->getEmitter()->on('before', function (BeforeEvent $e) {
165    // Guzzle v5 events relied on mutation
166    $e->getRequest()->setHeader('X-Foo', 'Bar');
167});
168```
169
170v6:
171
172In v6, you can modify the request before it is sent using the `mapRequest`
173middleware. The idiomatic way in v6 to modify the request/response lifecycle is
174to setup a handler middleware stack up front and inject the handler into a
175client.
176
177```php
178use GuzzleHttp\Middleware;
179// Create a handler stack that has all of the default middlewares attached
180$handler = GuzzleHttp\HandlerStack::create();
181// Push the handler onto the handler stack
182$handler->push(Middleware::mapRequest(function (RequestInterface $request) {
183    // Notice that we have to return a request object
184    return $request->withHeader('X-Foo', 'Bar');
185}));
186// Inject the handler into the client
187$client = new GuzzleHttp\Client(['handler' => $handler]);
188```
189
190## POST Requests
191
192This version added the [`form_params`](http://guzzle.readthedocs.org/en/latest/request-options.html#form_params)
193and `multipart` request options. `form_params` is an associative array of
194strings or array of strings and is used to serialize an
195`application/x-www-form-urlencoded` POST request. The
196[`multipart`](http://guzzle.readthedocs.org/en/latest/request-options.html#multipart)
197option is now used to send a multipart/form-data POST request.
198
199`GuzzleHttp\Post\PostFile` has been removed. Use the `multipart` option to add
200POST files to a multipart/form-data request.
201
202The `body` option no longer accepts an array to send POST requests. Please use
203`multipart` or `form_params` instead.
204
205The `base_url` option has been renamed to `base_uri`.
206
2074.x to 5.0
208----------
209
210## Rewritten Adapter Layer
211
212Guzzle now uses [RingPHP](http://ringphp.readthedocs.org/en/latest) to send
213HTTP requests. The `adapter` option in a `GuzzleHttp\Client` constructor
214is still supported, but it has now been renamed to `handler`. Instead of
215passing a `GuzzleHttp\Adapter\AdapterInterface`, you must now pass a PHP
216`callable` that follows the RingPHP specification.
217
218## Removed Fluent Interfaces
219
220[Fluent interfaces were removed](https://ocramius.github.io/blog/fluent-interfaces-are-evil/)
221from the following classes:
222
223- `GuzzleHttp\Collection`
224- `GuzzleHttp\Url`
225- `GuzzleHttp\Query`
226- `GuzzleHttp\Post\PostBody`
227- `GuzzleHttp\Cookie\SetCookie`
228
229## Removed functions.php
230
231Removed "functions.php", so that Guzzle is truly PSR-4 compliant. The following
232functions can be used as replacements.
233
234- `GuzzleHttp\json_decode` -> `GuzzleHttp\Utils::jsonDecode`
235- `GuzzleHttp\get_path` -> `GuzzleHttp\Utils::getPath`
236- `GuzzleHttp\Utils::setPath` -> `GuzzleHttp\set_path`
237- `GuzzleHttp\Pool::batch` -> `GuzzleHttp\batch`. This function is, however,
238  deprecated in favor of using `GuzzleHttp\Pool::batch()`.
239
240The "procedural" global client has been removed with no replacement (e.g.,
241`GuzzleHttp\get()`, `GuzzleHttp\post()`, etc.). Use a `GuzzleHttp\Client`
242object as a replacement.
243
244## `throwImmediately` has been removed
245
246The concept of "throwImmediately" has been removed from exceptions and error
247events. This control mechanism was used to stop a transfer of concurrent
248requests from completing. This can now be handled by throwing the exception or
249by cancelling a pool of requests or each outstanding future request
250individually.
251
252## headers event has been removed
253
254Removed the "headers" event. This event was only useful for changing the
255body a response once the headers of the response were known. You can implement
256a similar behavior in a number of ways. One example might be to use a
257FnStream that has access to the transaction being sent. For example, when the
258first byte is written, you could check if the response headers match your
259expectations, and if so, change the actual stream body that is being
260written to.
261
262## Updates to HTTP Messages
263
264Removed the `asArray` parameter from
265`GuzzleHttp\Message\MessageInterface::getHeader`. If you want to get a header
266value as an array, then use the newly added `getHeaderAsArray()` method of
267`MessageInterface`. This change makes the Guzzle interfaces compatible with
268the PSR-7 interfaces.
269
2703.x to 4.0
271----------
272
273## Overarching changes:
274
275- Now requires PHP 5.4 or greater.
276- No longer requires cURL to send requests.
277- Guzzle no longer wraps every exception it throws. Only exceptions that are
278  recoverable are now wrapped by Guzzle.
279- Various namespaces have been removed or renamed.
280- No longer requiring the Symfony EventDispatcher. A custom event dispatcher
281  based on the Symfony EventDispatcher is
282  now utilized in `GuzzleHttp\Event\EmitterInterface` (resulting in significant
283  speed and functionality improvements).
284
285Changes per Guzzle 3.x namespace are described below.
286
287## Batch
288
289The `Guzzle\Batch` namespace has been removed. This is best left to
290third-parties to implement on top of Guzzle's core HTTP library.
291
292## Cache
293
294The `Guzzle\Cache` namespace has been removed. (Todo: No suitable replacement
295has been implemented yet, but hoping to utilize a PSR cache interface).
296
297## Common
298
299- Removed all of the wrapped exceptions. It's better to use the standard PHP
300  library for unrecoverable exceptions.
301- `FromConfigInterface` has been removed.
302- `Guzzle\Common\Version` has been removed. The VERSION constant can be found
303  at `GuzzleHttp\ClientInterface::VERSION`.
304
305### Collection
306
307- `getAll` has been removed. Use `toArray` to convert a collection to an array.
308- `inject` has been removed.
309- `keySearch` has been removed.
310- `getPath` no longer supports wildcard expressions. Use something better like
311  JMESPath for this.
312- `setPath` now supports appending to an existing array via the `[]` notation.
313
314### Events
315
316Guzzle no longer requires Symfony's EventDispatcher component. Guzzle now uses
317`GuzzleHttp\Event\Emitter`.
318
319- `Symfony\Component\EventDispatcher\EventDispatcherInterface` is replaced by
320  `GuzzleHttp\Event\EmitterInterface`.
321- `Symfony\Component\EventDispatcher\EventDispatcher` is replaced by
322  `GuzzleHttp\Event\Emitter`.
323- `Symfony\Component\EventDispatcher\Event` is replaced by
324  `GuzzleHttp\Event\Event`, and Guzzle now has an EventInterface in
325  `GuzzleHttp\Event\EventInterface`.
326- `AbstractHasDispatcher` has moved to a trait, `HasEmitterTrait`, and
327  `HasDispatcherInterface` has moved to `HasEmitterInterface`. Retrieving the
328  event emitter of a request, client, etc. now uses the `getEmitter` method
329  rather than the `getDispatcher` method.
330
331#### Emitter
332
333- Use the `once()` method to add a listener that automatically removes itself
334  the first time it is invoked.
335- Use the `listeners()` method to retrieve a list of event listeners rather than
336  the `getListeners()` method.
337- Use `emit()` instead of `dispatch()` to emit an event from an emitter.
338- Use `attach()` instead of `addSubscriber()` and `detach()` instead of
339  `removeSubscriber()`.
340
341```php
342$mock = new Mock();
343// 3.x
344$request->getEventDispatcher()->addSubscriber($mock);
345$request->getEventDispatcher()->removeSubscriber($mock);
346// 4.x
347$request->getEmitter()->attach($mock);
348$request->getEmitter()->detach($mock);
349```
350
351Use the `on()` method to add a listener rather than the `addListener()` method.
352
353```php
354// 3.x
355$request->getEventDispatcher()->addListener('foo', function (Event $event) { /* ... */ } );
356// 4.x
357$request->getEmitter()->on('foo', function (Event $event, $name) { /* ... */ } );
358```
359
360## Http
361
362### General changes
363
364- The cacert.pem certificate has been moved to `src/cacert.pem`.
365- Added the concept of adapters that are used to transfer requests over the
366  wire.
367- Simplified the event system.
368- Sending requests in parallel is still possible, but batching is no longer a
369  concept of the HTTP layer. Instead, you must use the `complete` and `error`
370  events to asynchronously manage parallel request transfers.
371- `Guzzle\Http\Url` has moved to `GuzzleHttp\Url`.
372- `Guzzle\Http\QueryString` has moved to `GuzzleHttp\Query`.
373- QueryAggregators have been rewritten so that they are simply callable
374  functions.
375- `GuzzleHttp\StaticClient` has been removed. Use the functions provided in
376  `functions.php` for an easy to use static client instance.
377- Exceptions in `GuzzleHttp\Exception` have been updated to all extend from
378  `GuzzleHttp\Exception\TransferException`.
379
380### Client
381
382Calling methods like `get()`, `post()`, `head()`, etc. no longer create and
383return a request, but rather creates a request, sends the request, and returns
384the response.
385
386```php
387// 3.0
388$request = $client->get('/');
389$response = $request->send();
390
391// 4.0
392$response = $client->get('/');
393
394// or, to mirror the previous behavior
395$request = $client->createRequest('GET', '/');
396$response = $client->send($request);
397```
398
399`GuzzleHttp\ClientInterface` has changed.
400
401- The `send` method no longer accepts more than one request. Use `sendAll` to
402  send multiple requests in parallel.
403- `setUserAgent()` has been removed. Use a default request option instead. You
404  could, for example, do something like:
405  `$client->setConfig('defaults/headers/User-Agent', 'Foo/Bar ' . $client::getDefaultUserAgent())`.
406- `setSslVerification()` has been removed. Use default request options instead,
407  like `$client->setConfig('defaults/verify', true)`.
408
409`GuzzleHttp\Client` has changed.
410
411- The constructor now accepts only an associative array. You can include a
412  `base_url` string or array to use a URI template as the base URL of a client.
413  You can also specify a `defaults` key that is an associative array of default
414  request options. You can pass an `adapter` to use a custom adapter,
415  `batch_adapter` to use a custom adapter for sending requests in parallel, or
416  a `message_factory` to change the factory used to create HTTP requests and
417  responses.
418- The client no longer emits a `client.create_request` event.
419- Creating requests with a client no longer automatically utilize a URI
420  template. You must pass an array into a creational method (e.g.,
421  `createRequest`, `get`, `put`, etc.) in order to expand a URI template.
422
423### Messages
424
425Messages no longer have references to their counterparts (i.e., a request no
426longer has a reference to it's response, and a response no loger has a
427reference to its request). This association is now managed through a
428`GuzzleHttp\Adapter\TransactionInterface` object. You can get references to
429these transaction objects using request events that are emitted over the
430lifecycle of a request.
431
432#### Requests with a body
433
434- `GuzzleHttp\Message\EntityEnclosingRequest` and
435  `GuzzleHttp\Message\EntityEnclosingRequestInterface` have been removed. The
436  separation between requests that contain a body and requests that do not
437  contain a body has been removed, and now `GuzzleHttp\Message\RequestInterface`
438  handles both use cases.
439- Any method that previously accepts a `GuzzleHttp\Response` object now accept a
440  `GuzzleHttp\Message\ResponseInterface`.
441- `GuzzleHttp\Message\RequestFactoryInterface` has been renamed to
442  `GuzzleHttp\Message\MessageFactoryInterface`. This interface is used to create
443  both requests and responses and is implemented in
444  `GuzzleHttp\Message\MessageFactory`.
445- POST field and file methods have been removed from the request object. You
446  must now use the methods made available to `GuzzleHttp\Post\PostBodyInterface`
447  to control the format of a POST body. Requests that are created using a
448  standard `GuzzleHttp\Message\MessageFactoryInterface` will automatically use
449  a `GuzzleHttp\Post\PostBody` body if the body was passed as an array or if
450  the method is POST and no body is provided.
451
452```php
453$request = $client->createRequest('POST', '/');
454$request->getBody()->setField('foo', 'bar');
455$request->getBody()->addFile(new PostFile('file_key', fopen('/path/to/content', 'r')));
456```
457
458#### Headers
459
460- `GuzzleHttp\Message\Header` has been removed. Header values are now simply
461  represented by an array of values or as a string. Header values are returned
462  as a string by default when retrieving a header value from a message. You can
463  pass an optional argument of `true` to retrieve a header value as an array
464  of strings instead of a single concatenated string.
465- `GuzzleHttp\PostFile` and `GuzzleHttp\PostFileInterface` have been moved to
466  `GuzzleHttp\Post`. This interface has been simplified and now allows the
467  addition of arbitrary headers.
468- Custom headers like `GuzzleHttp\Message\Header\Link` have been removed. Most
469  of the custom headers are now handled separately in specific
470  subscribers/plugins, and `GuzzleHttp\Message\HeaderValues::parseParams()` has
471  been updated to properly handle headers that contain parameters (like the
472  `Link` header).
473
474#### Responses
475
476- `GuzzleHttp\Message\Response::getInfo()` and
477  `GuzzleHttp\Message\Response::setInfo()` have been removed. Use the event
478  system to retrieve this type of information.
479- `GuzzleHttp\Message\Response::getRawHeaders()` has been removed.
480- `GuzzleHttp\Message\Response::getMessage()` has been removed.
481- `GuzzleHttp\Message\Response::calculateAge()` and other cache specific
482  methods have moved to the CacheSubscriber.
483- Header specific helper functions like `getContentMd5()` have been removed.
484  Just use `getHeader('Content-MD5')` instead.
485- `GuzzleHttp\Message\Response::setRequest()` and
486  `GuzzleHttp\Message\Response::getRequest()` have been removed. Use the event
487  system to work with request and response objects as a transaction.
488- `GuzzleHttp\Message\Response::getRedirectCount()` has been removed. Use the
489  Redirect subscriber instead.
490- `GuzzleHttp\Message\Response::isSuccessful()` and other related methods have
491  been removed. Use `getStatusCode()` instead.
492
493#### Streaming responses
494
495Streaming requests can now be created by a client directly, returning a
496`GuzzleHttp\Message\ResponseInterface` object that contains a body stream
497referencing an open PHP HTTP stream.
498
499```php
500// 3.0
501use Guzzle\Stream\PhpStreamRequestFactory;
502$request = $client->get('/');
503$factory = new PhpStreamRequestFactory();
504$stream = $factory->fromRequest($request);
505$data = $stream->read(1024);
506
507// 4.0
508$response = $client->get('/', ['stream' => true]);
509// Read some data off of the stream in the response body
510$data = $response->getBody()->read(1024);
511```
512
513#### Redirects
514
515The `configureRedirects()` method has been removed in favor of a
516`allow_redirects` request option.
517
518```php
519// Standard redirects with a default of a max of 5 redirects
520$request = $client->createRequest('GET', '/', ['allow_redirects' => true]);
521
522// Strict redirects with a custom number of redirects
523$request = $client->createRequest('GET', '/', [
524    'allow_redirects' => ['max' => 5, 'strict' => true]
525]);
526```
527
528#### EntityBody
529
530EntityBody interfaces and classes have been removed or moved to
531`GuzzleHttp\Stream`. All classes and interfaces that once required
532`GuzzleHttp\EntityBodyInterface` now require
533`GuzzleHttp\Stream\StreamInterface`. Creating a new body for a request no
534longer uses `GuzzleHttp\EntityBody::factory` but now uses
535`GuzzleHttp\Stream\Stream::factory` or even better:
536`GuzzleHttp\Stream\create()`.
537
538- `Guzzle\Http\EntityBodyInterface` is now `GuzzleHttp\Stream\StreamInterface`
539- `Guzzle\Http\EntityBody` is now `GuzzleHttp\Stream\Stream`
540- `Guzzle\Http\CachingEntityBody` is now `GuzzleHttp\Stream\CachingStream`
541- `Guzzle\Http\ReadLimitEntityBody` is now `GuzzleHttp\Stream\LimitStream`
542- `Guzzle\Http\IoEmittyinEntityBody` has been removed.
543
544#### Request lifecycle events
545
546Requests previously submitted a large number of requests. The number of events
547emitted over the lifecycle of a request has been significantly reduced to make
548it easier to understand how to extend the behavior of a request. All events
549emitted during the lifecycle of a request now emit a custom
550`GuzzleHttp\Event\EventInterface` object that contains context providing
551methods and a way in which to modify the transaction at that specific point in
552time (e.g., intercept the request and set a response on the transaction).
553
554- `request.before_send` has been renamed to `before` and now emits a
555  `GuzzleHttp\Event\BeforeEvent`
556- `request.complete` has been renamed to `complete` and now emits a
557  `GuzzleHttp\Event\CompleteEvent`.
558- `request.sent` has been removed. Use `complete`.
559- `request.success` has been removed. Use `complete`.
560- `error` is now an event that emits a `GuzzleHttp\Event\ErrorEvent`.
561- `request.exception` has been removed. Use `error`.
562- `request.receive.status_line` has been removed.
563- `curl.callback.progress` has been removed. Use a custom `StreamInterface` to
564  maintain a status update.
565- `curl.callback.write` has been removed. Use a custom `StreamInterface` to
566  intercept writes.
567- `curl.callback.read` has been removed. Use a custom `StreamInterface` to
568  intercept reads.
569
570`headers` is a new event that is emitted after the response headers of a
571request have been received before the body of the response is downloaded. This
572event emits a `GuzzleHttp\Event\HeadersEvent`.
573
574You can intercept a request and inject a response using the `intercept()` event
575of a `GuzzleHttp\Event\BeforeEvent`, `GuzzleHttp\Event\CompleteEvent`, and
576`GuzzleHttp\Event\ErrorEvent` event.
577
578See: http://docs.guzzlephp.org/en/latest/events.html
579
580## Inflection
581
582The `Guzzle\Inflection` namespace has been removed. This is not a core concern
583of Guzzle.
584
585## Iterator
586
587The `Guzzle\Iterator` namespace has been removed.
588
589- `Guzzle\Iterator\AppendIterator`, `Guzzle\Iterator\ChunkedIterator`, and
590  `Guzzle\Iterator\MethodProxyIterator` are nice, but not a core requirement of
591  Guzzle itself.
592- `Guzzle\Iterator\FilterIterator` is no longer needed because an equivalent
593  class is shipped with PHP 5.4.
594- `Guzzle\Iterator\MapIterator` is not really needed when using PHP 5.5 because
595  it's easier to just wrap an iterator in a generator that maps values.
596
597For a replacement of these iterators, see https://github.com/nikic/iter
598
599## Log
600
601The LogPlugin has moved to https://github.com/guzzle/log-subscriber. The
602`Guzzle\Log` namespace has been removed. Guzzle now relies on
603`Psr\Log\LoggerInterface` for all logging. The MessageFormatter class has been
604moved to `GuzzleHttp\Subscriber\Log\Formatter`.
605
606## Parser
607
608The `Guzzle\Parser` namespace has been removed. This was previously used to
609make it possible to plug in custom parsers for cookies, messages, URI
610templates, and URLs; however, this level of complexity is not needed in Guzzle
611so it has been removed.
612
613- Cookie: Cookie parsing logic has been moved to
614  `GuzzleHttp\Cookie\SetCookie::fromString`.
615- Message: Message parsing logic for both requests and responses has been moved
616  to `GuzzleHttp\Message\MessageFactory::fromMessage`. Message parsing is only
617  used in debugging or deserializing messages, so it doesn't make sense for
618  Guzzle as a library to add this level of complexity to parsing messages.
619- UriTemplate: URI template parsing has been moved to
620  `GuzzleHttp\UriTemplate`. The Guzzle library will automatically use the PECL
621  URI template library if it is installed.
622- Url: URL parsing is now performed in `GuzzleHttp\Url::fromString` (previously
623  it was `Guzzle\Http\Url::factory()`). If custom URL parsing is necessary,
624  then developers are free to subclass `GuzzleHttp\Url`.
625
626## Plugin
627
628The `Guzzle\Plugin` namespace has been renamed to `GuzzleHttp\Subscriber`.
629Several plugins are shipping with the core Guzzle library under this namespace.
630
631- `GuzzleHttp\Subscriber\Cookie`: Replaces the old CookiePlugin. Cookie jar
632  code has moved to `GuzzleHttp\Cookie`.
633- `GuzzleHttp\Subscriber\History`: Replaces the old HistoryPlugin.
634- `GuzzleHttp\Subscriber\HttpError`: Throws errors when a bad HTTP response is
635  received.
636- `GuzzleHttp\Subscriber\Mock`: Replaces the old MockPlugin.
637- `GuzzleHttp\Subscriber\Prepare`: Prepares the body of a request just before
638  sending. This subscriber is attached to all requests by default.
639- `GuzzleHttp\Subscriber\Redirect`: Replaces the RedirectPlugin.
640
641The following plugins have been removed (third-parties are free to re-implement
642these if needed):
643
644- `GuzzleHttp\Plugin\Async` has been removed.
645- `GuzzleHttp\Plugin\CurlAuth` has been removed.
646- `GuzzleHttp\Plugin\ErrorResponse\ErrorResponsePlugin` has been removed. This
647  functionality should instead be implemented with event listeners that occur
648  after normal response parsing occurs in the guzzle/command package.
649
650The following plugins are not part of the core Guzzle package, but are provided
651in separate repositories:
652
653- `Guzzle\Http\Plugin\BackoffPlugin` has been rewritten to be much simpler
654  to build custom retry policies using simple functions rather than various
655  chained classes. See: https://github.com/guzzle/retry-subscriber
656- `Guzzle\Http\Plugin\Cache\CachePlugin` has moved to
657  https://github.com/guzzle/cache-subscriber
658- `Guzzle\Http\Plugin\Log\LogPlugin` has moved to
659  https://github.com/guzzle/log-subscriber
660- `Guzzle\Http\Plugin\Md5\Md5Plugin` has moved to
661  https://github.com/guzzle/message-integrity-subscriber
662- `Guzzle\Http\Plugin\Mock\MockPlugin` has moved to
663  `GuzzleHttp\Subscriber\MockSubscriber`.
664- `Guzzle\Http\Plugin\Oauth\OauthPlugin` has moved to
665  https://github.com/guzzle/oauth-subscriber
666
667## Service
668
669The service description layer of Guzzle has moved into two separate packages:
670
671- http://github.com/guzzle/command Provides a high level abstraction over web
672  services by representing web service operations using commands.
673- http://github.com/guzzle/guzzle-services Provides an implementation of
674  guzzle/command that provides request serialization and response parsing using
675  Guzzle service descriptions.
676
677## Stream
678
679Stream have moved to a separate package available at
680https://github.com/guzzle/streams.
681
682`Guzzle\Stream\StreamInterface` has been given a large update to cleanly take
683on the responsibilities of `Guzzle\Http\EntityBody` and
684`Guzzle\Http\EntityBodyInterface` now that they have been removed. The number
685of methods implemented by the `StreamInterface` has been drastically reduced to
686allow developers to more easily extend and decorate stream behavior.
687
688## Removed methods from StreamInterface
689
690- `getStream` and `setStream` have been removed to better encapsulate streams.
691- `getMetadata` and `setMetadata` have been removed in favor of
692  `GuzzleHttp\Stream\MetadataStreamInterface`.
693- `getWrapper`, `getWrapperData`, `getStreamType`, and `getUri` have all been
694  removed. This data is accessible when
695  using streams that implement `GuzzleHttp\Stream\MetadataStreamInterface`.
696- `rewind` has been removed. Use `seek(0)` for a similar behavior.
697
698## Renamed methods
699
700- `detachStream` has been renamed to `detach`.
701- `feof` has been renamed to `eof`.
702- `ftell` has been renamed to `tell`.
703- `readLine` has moved from an instance method to a static class method of
704  `GuzzleHttp\Stream\Stream`.
705
706## Metadata streams
707
708`GuzzleHttp\Stream\MetadataStreamInterface` has been added to denote streams
709that contain additional metadata accessible via `getMetadata()`.
710`GuzzleHttp\Stream\StreamInterface::getMetadata` and
711`GuzzleHttp\Stream\StreamInterface::setMetadata` have been removed.
712
713## StreamRequestFactory
714
715The entire concept of the StreamRequestFactory has been removed. The way this
716was used in Guzzle 3 broke the actual interface of sending streaming requests
717(instead of getting back a Response, you got a StreamInterface). Streaming
718PHP requests are now implemented through the `GuzzleHttp\Adapter\StreamAdapter`.
719
7203.6 to 3.7
721----------
722
723### Deprecations
724
725- You can now enable E_USER_DEPRECATED warnings to see if you are using any deprecated methods.:
726
727```php
728\Guzzle\Common\Version::$emitWarnings = true;
729```
730
731The following APIs and options have been marked as deprecated:
732
733- Marked `Guzzle\Http\Message\Request::isResponseBodyRepeatable()` as deprecated. Use `$request->getResponseBody()->isRepeatable()` instead.
734- Marked `Guzzle\Http\Message\Request::canCache()` as deprecated. Use `Guzzle\Plugin\Cache\DefaultCanCacheStrategy->canCacheRequest()` instead.
735- Marked `Guzzle\Http\Message\Request::canCache()` as deprecated. Use `Guzzle\Plugin\Cache\DefaultCanCacheStrategy->canCacheRequest()` instead.
736- Marked `Guzzle\Http\Message\Request::setIsRedirect()` as deprecated. Use the HistoryPlugin instead.
737- Marked `Guzzle\Http\Message\Request::isRedirect()` as deprecated. Use the HistoryPlugin instead.
738- Marked `Guzzle\Cache\CacheAdapterFactory::factory()` as deprecated
739- Marked `Guzzle\Service\Client::enableMagicMethods()` as deprecated. Magic methods can no longer be disabled on a Guzzle\Service\Client.
740- Marked `Guzzle\Parser\Url\UrlParser` as deprecated. Just use PHP's `parse_url()` and percent encode your UTF-8.
741- Marked `Guzzle\Common\Collection::inject()` as deprecated.
742- Marked `Guzzle\Plugin\CurlAuth\CurlAuthPlugin` as deprecated. Use
743  `$client->getConfig()->setPath('request.options/auth', array('user', 'pass', 'Basic|Digest|NTLM|Any'));` or
744  `$client->setDefaultOption('auth', array('user', 'pass', 'Basic|Digest|NTLM|Any'));`
745
7463.7 introduces `request.options` as a parameter for a client configuration and as an optional argument to all creational
747request methods. When paired with a client's configuration settings, these options allow you to specify default settings
748for various aspects of a request. Because these options make other previous configuration options redundant, several
749configuration options and methods of a client and AbstractCommand have been deprecated.
750
751- Marked `Guzzle\Service\Client::getDefaultHeaders()` as deprecated. Use `$client->getDefaultOption('headers')`.
752- Marked `Guzzle\Service\Client::setDefaultHeaders()` as deprecated. Use `$client->setDefaultOption('headers/{header_name}', 'value')`.
753- Marked 'request.params' for `Guzzle\Http\Client` as deprecated. Use `$client->setDefaultOption('params/{param_name}', 'value')`
754- Marked 'command.headers', 'command.response_body' and 'command.on_complete' as deprecated for AbstractCommand. These will work through Guzzle 4.0
755
756        $command = $client->getCommand('foo', array(
757            'command.headers' => array('Test' => '123'),
758            'command.response_body' => '/path/to/file'
759        ));
760
761        // Should be changed to:
762
763        $command = $client->getCommand('foo', array(
764            'command.request_options' => array(
765                'headers' => array('Test' => '123'),
766                'save_as' => '/path/to/file'
767            )
768        ));
769
770### Interface changes
771
772Additions and changes (you will need to update any implementations or subclasses you may have created):
773
774- Added an `$options` argument to the end of the following methods of `Guzzle\Http\ClientInterface`:
775  createRequest, head, delete, put, patch, post, options, prepareRequest
776- Added an `$options` argument to the end of `Guzzle\Http\Message\Request\RequestFactoryInterface::createRequest()`
777- Added an `applyOptions()` method to `Guzzle\Http\Message\Request\RequestFactoryInterface`
778- Changed `Guzzle\Http\ClientInterface::get($uri = null, $headers = null, $body = null)` to
779  `Guzzle\Http\ClientInterface::get($uri = null, $headers = null, $options = array())`. You can still pass in a
780  resource, string, or EntityBody into the $options parameter to specify the download location of the response.
781- Changed `Guzzle\Common\Collection::__construct($data)` to no longer accepts a null value for `$data` but a
782  default `array()`
783- Added `Guzzle\Stream\StreamInterface::isRepeatable`
784- Made `Guzzle\Http\Client::expandTemplate` and `getUriTemplate` protected methods.
785
786The following methods were removed from interfaces. All of these methods are still available in the concrete classes
787that implement them, but you should update your code to use alternative methods:
788
789- Removed `Guzzle\Http\ClientInterface::setDefaultHeaders(). Use
790  `$client->getConfig()->setPath('request.options/headers/{header_name}', 'value')`. or
791  `$client->getConfig()->setPath('request.options/headers', array('header_name' => 'value'))` or
792  `$client->setDefaultOption('headers/{header_name}', 'value')`. or
793  `$client->setDefaultOption('headers', array('header_name' => 'value'))`.
794- Removed `Guzzle\Http\ClientInterface::getDefaultHeaders(). Use `$client->getConfig()->getPath('request.options/headers')`.
795- Removed `Guzzle\Http\ClientInterface::expandTemplate()`. This is an implementation detail.
796- Removed `Guzzle\Http\ClientInterface::setRequestFactory()`. This is an implementation detail.
797- Removed `Guzzle\Http\ClientInterface::getCurlMulti()`. This is a very specific implementation detail.
798- Removed `Guzzle\Http\Message\RequestInterface::canCache`. Use the CachePlugin.
799- Removed `Guzzle\Http\Message\RequestInterface::setIsRedirect`. Use the HistoryPlugin.
800- Removed `Guzzle\Http\Message\RequestInterface::isRedirect`. Use the HistoryPlugin.
801
802### Cache plugin breaking changes
803
804- CacheKeyProviderInterface and DefaultCacheKeyProvider are no longer used. All of this logic is handled in a
805  CacheStorageInterface. These two objects and interface will be removed in a future version.
806- Always setting X-cache headers on cached responses
807- Default cache TTLs are now handled by the CacheStorageInterface of a CachePlugin
808- `CacheStorageInterface::cache($key, Response $response, $ttl = null)` has changed to `cache(RequestInterface
809  $request, Response $response);`
810- `CacheStorageInterface::fetch($key)` has changed to `fetch(RequestInterface $request);`
811- `CacheStorageInterface::delete($key)` has changed to `delete(RequestInterface $request);`
812- Added `CacheStorageInterface::purge($url)`
813- `DefaultRevalidation::__construct(CacheKeyProviderInterface $cacheKey, CacheStorageInterface $cache, CachePlugin
814  $plugin)` has changed to `DefaultRevalidation::__construct(CacheStorageInterface $cache,
815  CanCacheStrategyInterface $canCache = null)`
816- Added `RevalidationInterface::shouldRevalidate(RequestInterface $request, Response $response)`
817
8183.5 to 3.6
819----------
820
821* Mixed casing of headers are now forced to be a single consistent casing across all values for that header.
822* Messages internally use a HeaderCollection object to delegate handling case-insensitive header resolution
823* Removed the whole changedHeader() function system of messages because all header changes now go through addHeader().
824  For example, setHeader() first removes the header using unset on a HeaderCollection and then calls addHeader().
825  Keeping the Host header and URL host in sync is now handled by overriding the addHeader method in Request.
826* Specific header implementations can be created for complex headers. When a message creates a header, it uses a
827  HeaderFactory which can map specific headers to specific header classes. There is now a Link header and
828  CacheControl header implementation.
829* Moved getLinks() from Response to just be used on a Link header object.
830
831If you previously relied on Guzzle\Http\Message\Header::raw(), then you will need to update your code to use the
832HeaderInterface (e.g. toArray(), getAll(), etc.).
833
834### Interface changes
835
836* Removed from interface: Guzzle\Http\ClientInterface::setUriTemplate
837* Removed from interface: Guzzle\Http\ClientInterface::setCurlMulti()
838* Removed Guzzle\Http\Message\Request::receivedRequestHeader() and implemented this functionality in
839  Guzzle\Http\Curl\RequestMediator
840* Removed the optional $asString parameter from MessageInterface::getHeader(). Just cast the header to a string.
841* Removed the optional $tryChunkedTransfer option from Guzzle\Http\Message\EntityEnclosingRequestInterface
842* Removed the $asObjects argument from Guzzle\Http\Message\MessageInterface::getHeaders()
843
844### Removed deprecated functions
845
846* Removed Guzzle\Parser\ParserRegister::get(). Use getParser()
847* Removed Guzzle\Parser\ParserRegister::set(). Use registerParser().
848
849### Deprecations
850
851* The ability to case-insensitively search for header values
852* Guzzle\Http\Message\Header::hasExactHeader
853* Guzzle\Http\Message\Header::raw. Use getAll()
854* Deprecated cache control specific methods on Guzzle\Http\Message\AbstractMessage. Use the CacheControl header object
855  instead.
856
857### Other changes
858
859* All response header helper functions return a string rather than mixing Header objects and strings inconsistently
860* Removed cURL blacklist support. This is no longer necessary now that Expect, Accept, etc. are managed by Guzzle
861  directly via interfaces
862* Removed the injecting of a request object onto a response object. The methods to get and set a request still exist
863  but are a no-op until removed.
864* Most classes that used to require a `Guzzle\Service\Command\CommandInterface` typehint now request a
865  `Guzzle\Service\Command\ArrayCommandInterface`.
866* Added `Guzzle\Http\Message\RequestInterface::startResponse()` to the RequestInterface to handle injecting a response
867  on a request while the request is still being transferred
868* `Guzzle\Service\Command\CommandInterface` now extends from ToArrayInterface and ArrayAccess
869
8703.3 to 3.4
871----------
872
873Base URLs of a client now follow the rules of https://tools.ietf.org/html/rfc3986#section-5.2.2 when merging URLs.
874
8753.2 to 3.3
876----------
877
878### Response::getEtag() quote stripping removed
879
880`Guzzle\Http\Message\Response::getEtag()` no longer strips quotes around the ETag response header
881
882### Removed `Guzzle\Http\Utils`
883
884The `Guzzle\Http\Utils` class was removed. This class was only used for testing.
885
886### Stream wrapper and type
887
888`Guzzle\Stream\Stream::getWrapper()` and `Guzzle\Stream\Stream::getStreamType()` are no longer converted to lowercase.
889
890### curl.emit_io became emit_io
891
892Emitting IO events from a RequestMediator is now a parameter that must be set in a request's curl options using the
893'emit_io' key. This was previously set under a request's parameters using 'curl.emit_io'
894
8953.1 to 3.2
896----------
897
898### CurlMulti is no longer reused globally
899
900Before 3.2, the same CurlMulti object was reused globally for each client. This can cause issue where plugins added
901to a single client can pollute requests dispatched from other clients.
902
903If you still wish to reuse the same CurlMulti object with each client, then you can add a listener to the
904ServiceBuilder's `service_builder.create_client` event to inject a custom CurlMulti object into each client as it is
905created.
906
907```php
908$multi = new Guzzle\Http\Curl\CurlMulti();
909$builder = Guzzle\Service\Builder\ServiceBuilder::factory('/path/to/config.json');
910$builder->addListener('service_builder.create_client', function ($event) use ($multi) {
911    $event['client']->setCurlMulti($multi);
912}
913});
914```
915
916### No default path
917
918URLs no longer have a default path value of '/' if no path was specified.
919
920Before:
921
922```php
923$request = $client->get('http://www.foo.com');
924echo $request->getUrl();
925// >> http://www.foo.com/
926```
927
928After:
929
930```php
931$request = $client->get('http://www.foo.com');
932echo $request->getUrl();
933// >> http://www.foo.com
934```
935
936### Less verbose BadResponseException
937
938The exception message for `Guzzle\Http\Exception\BadResponseException` no longer contains the full HTTP request and
939response information. You can, however, get access to the request and response object by calling `getRequest()` or
940`getResponse()` on the exception object.
941
942### Query parameter aggregation
943
944Multi-valued query parameters are no longer aggregated using a callback function. `Guzzle\Http\Query` now has a
945setAggregator() method that accepts a `Guzzle\Http\QueryAggregator\QueryAggregatorInterface` object. This object is
946responsible for handling the aggregation of multi-valued query string variables into a flattened hash.
947
9482.8 to 3.x
949----------
950
951### Guzzle\Service\Inspector
952
953Change `\Guzzle\Service\Inspector::fromConfig` to `\Guzzle\Common\Collection::fromConfig`
954
955**Before**
956
957```php
958use Guzzle\Service\Inspector;
959
960class YourClient extends \Guzzle\Service\Client
961{
962    public static function factory($config = array())
963    {
964        $default = array();
965        $required = array('base_url', 'username', 'api_key');
966        $config = Inspector::fromConfig($config, $default, $required);
967
968        $client = new self(
969            $config->get('base_url'),
970            $config->get('username'),
971            $config->get('api_key')
972        );
973        $client->setConfig($config);
974
975        $client->setDescription(ServiceDescription::factory(__DIR__ . DIRECTORY_SEPARATOR . 'client.json'));
976
977        return $client;
978    }
979```
980
981**After**
982
983```php
984use Guzzle\Common\Collection;
985
986class YourClient extends \Guzzle\Service\Client
987{
988    public static function factory($config = array())
989    {
990        $default = array();
991        $required = array('base_url', 'username', 'api_key');
992        $config = Collection::fromConfig($config, $default, $required);
993
994        $client = new self(
995            $config->get('base_url'),
996            $config->get('username'),
997            $config->get('api_key')
998        );
999        $client->setConfig($config);
1000
1001        $client->setDescription(ServiceDescription::factory(__DIR__ . DIRECTORY_SEPARATOR . 'client.json'));
1002
1003        return $client;
1004    }
1005```
1006
1007### Convert XML Service Descriptions to JSON
1008
1009**Before**
1010
1011```xml
1012<?xml version="1.0" encoding="UTF-8"?>
1013<client>
1014    <commands>
1015        <!-- Groups -->
1016        <command name="list_groups" method="GET" uri="groups.json">
1017            <doc>Get a list of groups</doc>
1018        </command>
1019        <command name="search_groups" method="GET" uri='search.json?query="{{query}} type:group"'>
1020            <doc>Uses a search query to get a list of groups</doc>
1021            <param name="query" type="string" required="true" />
1022        </command>
1023        <command name="create_group" method="POST" uri="groups.json">
1024            <doc>Create a group</doc>
1025            <param name="data" type="array" location="body" filters="json_encode" doc="Group JSON"/>
1026            <param name="Content-Type" location="header" static="application/json"/>
1027        </command>
1028        <command name="delete_group" method="DELETE" uri="groups/{{id}}.json">
1029            <doc>Delete a group by ID</doc>
1030            <param name="id" type="integer" required="true"/>
1031        </command>
1032        <command name="get_group" method="GET" uri="groups/{{id}}.json">
1033            <param name="id" type="integer" required="true"/>
1034        </command>
1035        <command name="update_group" method="PUT" uri="groups/{{id}}.json">
1036            <doc>Update a group</doc>
1037            <param name="id" type="integer" required="true"/>
1038            <param name="data" type="array" location="body" filters="json_encode" doc="Group JSON"/>
1039            <param name="Content-Type" location="header" static="application/json"/>
1040        </command>
1041    </commands>
1042</client>
1043```
1044
1045**After**
1046
1047```json
1048{
1049    "name":       "Zendesk REST API v2",
1050    "apiVersion": "2012-12-31",
1051    "description":"Provides access to Zendesk views, groups, tickets, ticket fields, and users",
1052    "operations": {
1053        "list_groups":  {
1054            "httpMethod":"GET",
1055            "uri":       "groups.json",
1056            "summary":   "Get a list of groups"
1057        },
1058        "search_groups":{
1059            "httpMethod":"GET",
1060            "uri":       "search.json?query=\"{query} type:group\"",
1061            "summary":   "Uses a search query to get a list of groups",
1062            "parameters":{
1063                "query":{
1064                    "location":   "uri",
1065                    "description":"Zendesk Search Query",
1066                    "type":       "string",
1067                    "required":   true
1068                }
1069            }
1070        },
1071        "create_group": {
1072            "httpMethod":"POST",
1073            "uri":       "groups.json",
1074            "summary":   "Create a group",
1075            "parameters":{
1076                "data":        {
1077                    "type":       "array",
1078                    "location":   "body",
1079                    "description":"Group JSON",
1080                    "filters":    "json_encode",
1081                    "required":   true
1082                },
1083                "Content-Type":{
1084                    "type":    "string",
1085                    "location":"header",
1086                    "static":  "application/json"
1087                }
1088            }
1089        },
1090        "delete_group": {
1091            "httpMethod":"DELETE",
1092            "uri":       "groups/{id}.json",
1093            "summary":   "Delete a group",
1094            "parameters":{
1095                "id":{
1096                    "location":   "uri",
1097                    "description":"Group to delete by ID",
1098                    "type":       "integer",
1099                    "required":   true
1100                }
1101            }
1102        },
1103        "get_group":    {
1104            "httpMethod":"GET",
1105            "uri":       "groups/{id}.json",
1106            "summary":   "Get a ticket",
1107            "parameters":{
1108                "id":{
1109                    "location":   "uri",
1110                    "description":"Group to get by ID",
1111                    "type":       "integer",
1112                    "required":   true
1113                }
1114            }
1115        },
1116        "update_group": {
1117            "httpMethod":"PUT",
1118            "uri":       "groups/{id}.json",
1119            "summary":   "Update a group",
1120            "parameters":{
1121                "id":          {
1122                    "location":   "uri",
1123                    "description":"Group to update by ID",
1124                    "type":       "integer",
1125                    "required":   true
1126                },
1127                "data":        {
1128                    "type":       "array",
1129                    "location":   "body",
1130                    "description":"Group JSON",
1131                    "filters":    "json_encode",
1132                    "required":   true
1133                },
1134                "Content-Type":{
1135                    "type":    "string",
1136                    "location":"header",
1137                    "static":  "application/json"
1138                }
1139            }
1140        }
1141}
1142```
1143
1144### Guzzle\Service\Description\ServiceDescription
1145
1146Commands are now called Operations
1147
1148**Before**
1149
1150```php
1151use Guzzle\Service\Description\ServiceDescription;
1152
1153$sd = new ServiceDescription();
1154$sd->getCommands();     // @returns ApiCommandInterface[]
1155$sd->hasCommand($name);
1156$sd->getCommand($name); // @returns ApiCommandInterface|null
1157$sd->addCommand($command); // @param ApiCommandInterface $command
1158```
1159
1160**After**
1161
1162```php
1163use Guzzle\Service\Description\ServiceDescription;
1164
1165$sd = new ServiceDescription();
1166$sd->getOperations();           // @returns OperationInterface[]
1167$sd->hasOperation($name);
1168$sd->getOperation($name);       // @returns OperationInterface|null
1169$sd->addOperation($operation);  // @param OperationInterface $operation
1170```
1171
1172### Guzzle\Common\Inflection\Inflector
1173
1174Namespace is now `Guzzle\Inflection\Inflector`
1175
1176### Guzzle\Http\Plugin
1177
1178Namespace is now `Guzzle\Plugin`. Many other changes occur within this namespace and are detailed in their own sections below.
1179
1180### Guzzle\Http\Plugin\LogPlugin and Guzzle\Common\Log
1181
1182Now `Guzzle\Plugin\Log\LogPlugin` and `Guzzle\Log` respectively.
1183
1184**Before**
1185
1186```php
1187use Guzzle\Common\Log\ClosureLogAdapter;
1188use Guzzle\Http\Plugin\LogPlugin;
1189
1190/** @var \Guzzle\Http\Client */
1191$client;
1192
1193// $verbosity is an integer indicating desired message verbosity level
1194$client->addSubscriber(new LogPlugin(new ClosureLogAdapter(function($m) { echo $m; }, $verbosity = LogPlugin::LOG_VERBOSE);
1195```
1196
1197**After**
1198
1199```php
1200use Guzzle\Log\ClosureLogAdapter;
1201use Guzzle\Log\MessageFormatter;
1202use Guzzle\Plugin\Log\LogPlugin;
1203
1204/** @var \Guzzle\Http\Client */
1205$client;
1206
1207// $format is a string indicating desired message format -- @see MessageFormatter
1208$client->addSubscriber(new LogPlugin(new ClosureLogAdapter(function($m) { echo $m; }, $format = MessageFormatter::DEBUG_FORMAT);
1209```
1210
1211### Guzzle\Http\Plugin\CurlAuthPlugin
1212
1213Now `Guzzle\Plugin\CurlAuth\CurlAuthPlugin`.
1214
1215### Guzzle\Http\Plugin\ExponentialBackoffPlugin
1216
1217Now `Guzzle\Plugin\Backoff\BackoffPlugin`, and other changes.
1218
1219**Before**
1220
1221```php
1222use Guzzle\Http\Plugin\ExponentialBackoffPlugin;
1223
1224$backoffPlugin = new ExponentialBackoffPlugin($maxRetries, array_merge(
1225        ExponentialBackoffPlugin::getDefaultFailureCodes(), array(429)
1226    ));
1227
1228$client->addSubscriber($backoffPlugin);
1229```
1230
1231**After**
1232
1233```php
1234use Guzzle\Plugin\Backoff\BackoffPlugin;
1235use Guzzle\Plugin\Backoff\HttpBackoffStrategy;
1236
1237// Use convenient factory method instead -- see implementation for ideas of what
1238// you can do with chaining backoff strategies
1239$backoffPlugin = BackoffPlugin::getExponentialBackoff($maxRetries, array_merge(
1240        HttpBackoffStrategy::getDefaultFailureCodes(), array(429)
1241    ));
1242$client->addSubscriber($backoffPlugin);
1243```
1244
1245### Known Issues
1246
1247#### [BUG] Accept-Encoding header behavior changed unintentionally.
1248
1249(See #217) (Fixed in 09daeb8c666fb44499a0646d655a8ae36456575e)
1250
1251In version 2.8 setting the `Accept-Encoding` header would set the CURLOPT_ENCODING option, which permitted cURL to
1252properly handle gzip/deflate compressed responses from the server. In versions affected by this bug this does not happen.
1253See issue #217 for a workaround, or use a version containing the fix.
1254