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docs/guide-ru/rest-response-formatting.md

+Response Formatting
+===================
+
+When handling a RESTful API request, an application usually takes the following steps that are related
+with response formatting:
+
+1. Determine various factors that may affect the response format, such as media type, language, version, etc.
+   This process is also known as [content negotiation](http://en.wikipedia.org/wiki/Content_negotiation).
+2. Convert resource objects into arrays, as described in the [Resources](rest-resources.md) section.
+   This is done by [[yii\rest\Serializer]].
+3. Convert arrays into a string in the format as determined by the content negotiation step. This is
+   done by [[yii\web\ResponseFormatterInterface|response formatters]] registered with
+   the [[yii\web\Response::formatters|response]] application component.
+
+
+## Content Negotiation <a name="content-negotiation"></a>
+
+Yii supports content negotiation via the [[yii\filters\ContentNegotiator]] filter. The RESTful API base
+controller class [[yii\rest\Controller]] is equipped with this filter under the name of `contentNegotiator`.
+The filer provides response format negotiation as well as language negotiation. For example, if a RESTful
+API request contains the following header,
+
+```
+Accept: application/json; q=1.0, */*; q=0.1
+```
+
+it will get a response in JSON format, like the following:
+
+```
+$ curl -i -H "Accept: application/json; q=1.0, */*; q=0.1" "http://localhost/users"
+
+HTTP/1.1 200 OK
+Date: Sun, 02 Mar 2014 05:31:43 GMT
+Server: Apache/2.2.26 (Unix) DAV/2 PHP/5.4.20 mod_ssl/2.2.26 OpenSSL/0.9.8y
+X-Powered-By: PHP/5.4.20
+X-Pagination-Total-Count: 1000
+X-Pagination-Page-Count: 50
+X-Pagination-Current-Page: 1
+X-Pagination-Per-Page: 20
+Link: <http://localhost/users?page=1>; rel=self,
+      <http://localhost/users?page=2>; rel=next,
+      <http://localhost/users?page=50>; rel=last
+Transfer-Encoding: chunked
+Content-Type: application/json; charset=UTF-8
+
+[
+    {
+        "id": 1,
+        ...
+    },
+    {
+        "id": 2,
+        ...
+    },
+    ...
+]
+```
+
+Behind the scene, before a RESTful API controller action is executed, the [[yii\filters\ContentNegotiator]]
+filter will check the `Accept` HTTP header in the request and set the [[yii\web\Response::format|response format]]
+to be `'json'`. After the action is executed and returns the resulting resource object or collection,
+[[yii\rest\Serializer]] will convert the result into an array. And finally, [[yii\web\JsonResponseFormatter]]
+will serialize the array into a JSON string and include it in the response body.
+
+By default, RESTful APIs support both JSON and XML formats. To support a new format, you should configure
+the [[yii\filters\ContentNegotiator::formats|formats]] property of the `contentNegotiator` filter like
+the following in your API controller classes:
+
+```php
+use yii\web\Response;
+
+public function behaviors()
+{
+    $behaviors = parent::behaviors();
+    $behaviors['contentNegotiator']['formats']['text/html'] = Response::FORMAT_HTML;
+    return $behaviors;
+}
+```
+
+The keys of the `formats` property are the supported MIME types, while the values are the corresponding
+response format names which must be supported in [[yii\web\Response::formatters]].
+
+
+## Data Serializing <a name="data-serializing"></a>
+
+As we have described above, [[yii\rest\Serializer]] is the central piece responsible for converting resource
+objects or collections into arrays. It recognizes objects implementing [[yii\base\ArrayableInterface]] as
+well as [[yii\data\DataProviderInterface]]. The former is mainly implemented by resource objects, while
+the latter resource collections.
+
+You may configure the serializer by setting the [[yii\rest\Controller::serializer]] property with a configuration array.
+For example, sometimes you may want to help simplify the client development work by including pagination information
+directly in the response body. To do so, configure the [[yii\rest\Serializer::collectionEnvelope]] property
+as follows:
+
+```php
+use yii\rest\ActiveController;
+
+class UserController extends ActiveController
+{
+    public $modelClass = 'app\models\User';
+    public $serializer = [
+        'class' => 'yii\rest\Serializer',
+        'collectionEnvelope' => 'items',
+    ];
+}
+```
+
+You may then get the following response for request `http://localhost/users`:
+
+```
+HTTP/1.1 200 OK
+Date: Sun, 02 Mar 2014 05:31:43 GMT
+Server: Apache/2.2.26 (Unix) DAV/2 PHP/5.4.20 mod_ssl/2.2.26 OpenSSL/0.9.8y
+X-Powered-By: PHP/5.4.20
+X-Pagination-Total-Count: 1000
+X-Pagination-Page-Count: 50
+X-Pagination-Current-Page: 1
+X-Pagination-Per-Page: 20
+Link: <http://localhost/users?page=1>; rel=self,
+      <http://localhost/users?page=2>; rel=next,
+      <http://localhost/users?page=50>; rel=last
+Transfer-Encoding: chunked
+Content-Type: application/json; charset=UTF-8
+
+{
+    "items": [
+        {
+            "id": 1,
+            ...
+        },
+        {
+            "id": 2,
+            ...
+        },
+        ...
+    ],
+    "_links": {
+        "self": "http://localhost/users?page=1",
+        "next": "http://localhost/users?page=2",
+        "last": "http://localhost/users?page=50"
+    },
+    "_meta": {
+        "totalCount": 1000,
+        "pageCount": 50,
+        "currentPage": 1,
+        "perPage": 20
+    }
+}
+```