docs/guide-ja/runtime-requests.md - prepared for translation [ci skip]

docs/guide-ja/runtime-requests.md

+Requests
+========
+
+Requests made to an application are represented in terms of [[yii\web\Request]] objects which provide information
+such as request parameters, HTTP headers, cookies, etc. For a given request, you can get access to the corresponding
+request object via the `request` [application component](structure-application-components.md) which is an instance
+of [[yii\web\Request]], by default. In this section, we will describe how you can make use of this component in your applications.
+
+
+## Request Parameters <a name="request-parameters"></a>
+
+To get request parameters, you can call [[yii\web\Request::get()|get()]] and [[yii\web\Request::post()|post()]] methods
+of the `request` component. They return the values of `$_GET` and `$_POST`, respectively. For example,
+
+```php
+$request = Yii::$app->request;
+
+$get = $request->get(); 
+// equivalent to: $get = $_GET;
+
+$id = $request->get('id');   
+// equivalent to: $id = isset($_GET['id']) ? $_GET['id'] : null;
+
+$id = $request->get('id', 1);   
+// equivalent to: $id = isset($_GET['id']) ? $_GET['id'] : 1;
+
+$post = $request->post(); 
+// equivalent to: $post = $_POST;
+
+$name = $request->post('name');   
+// equivalent to: $name = isset($_POST['name']) ? $_POST['name'] : null;
+
+$name = $request->post('name', '');   
+// equivalent to: $name = isset($_POST['name']) ? $_POST['name'] : '';
+```
+
+> Info: Instead of directly accessing `$_GET` and `$_POST` to retrieve the request parameters, it is recommended
+  that you get them via the `request` component like shown above. This will make writing tests easier because
+  you can create a mock request component with faked request data.
+
+When implementing [RESTful APIs](rest-quick-start.md), you often need to retrieve parameters that are submitted
+via PUT, PATCH or other [request methods](#request-methods). You can get these parameters by calling
+the [[yii\web\Request::getBodyParam()]] methods. For example,
+
+```php
+$request = Yii::$app->request;
+
+// returns all parameters
+$params = $request->bodyParams;
+
+// returns the parameter "id"
+$param = $request->getBodyParam('id');
+```
+
+> Info: Unlike `GET` parameters, parameters submitted via `POST`, `PUT`, `PATCH` etc. are sent in the request body.
+  The `request` component will parse these parameters when you access them through the methods described above.
+  You can customize the way how these parameters are parsed by configuring the [[yii\web\Request::parsers]] property.
+  
+
+## Request Methods <a name="request-methods"></a>
+
+You can get the HTTP method used by the current request via the expression `Yii::$app->request->method`.
+A whole set of boolean properties are also provided for you to check if the current method is of certain type.
+For example,
+
+```php
+$request = Yii::$app->request;
+
+if ($request->isAjax) { // the request is an AJAX request }
+if ($request->isGet)  { // the request method is GET }
+if ($request->isPost) { // the request method is POST }
+if ($request->isPut)  { // the request method is PUT }
+```
+
+## Request URLs <a name="request-urls"></a>
+
+The `request` component provides many ways of inspecting the currently requested URL. 
+
+Assuming the URL being requested is `http://example.com/admin/index.php/product?id=100`, you can get various
+parts of this URL as summarized in the following:
+
+* [[yii\web\Request::url|url]]: returns `/admin/index.php/product?id=100`, which is the URL without the host info part. 
+* [[yii\web\Request::absoluteUrl|absoluteUrl]]: returns `http://example.com/admin/index.php/product?id=100`,
+  which is the whole URL including the host info part.
+* [[yii\web\Request::hostInfo|hostInfo]]: returns `http://example.com`, which is the host info part of the URL.
+* [[yii\web\Request::pathInfo|pathInfo]]: returns `/product`, which is the part after the entry script and 
+  before the question mark (query string).
+* [[yii\web\Request::queryString|queryString]]: returns `id=100`, which is the part after the question mark. 
+* [[yii\web\Request::baseUrl|baseUrl]]: returns `/admin`, which is the part after the host info and before
+  the entry script name.
+* [[yii\web\Request::scriptUrl|scriptUrl]]: returns `/admin/index.php`, which is the URL without path info and query string.
+* [[yii\web\Request::serverName|serverName]]: returns `example.com`, which is the host name in the URL.
+* [[yii\web\Request::serverPort|serverPort]]: returns 80, which is the port used by the Web server.
+
+
+## HTTP Headers <a name="http-headers"></a> 
+
+You can get the HTTP header information through the [[yii\web\HeaderCollection|header collection]] returned 
+by the [[yii\web\Request::headers]] property. For example,
+
+```php
+// $headers is an object of yii\web\HeaderCollection 
+$headers = Yii::$app->request->headers;
+
+// returns the Accept header value
+$accept = $headers->get('Accept');
+
+if ($headers->has('User-Agent')) { // there is User-Agent header }
+```
+
+The `request` component also provides support for quickly accessing some commonly used headers, including
+
+* [[yii\web\Request::userAgent|userAgent]]: returns the value of the `User-Agent` header.
+* [[yii\web\Request::contentType|contentType]]: returns the value of the `Content-Type` header which indicates
+  the MIME type of the data in the request body.
+* [[yii\web\Request::acceptableContentTypes|acceptableContentTypes]]: returns the content MIME types acceptable by users.
+  The returned types ordered by the quality score. Types with the highest scores will be returned first.
+* [[yii\web\Request::acceptableLanguages|acceptableLanguages]]: returns the languages acceptable by users.
+  The returned languages are ordered by their preference level. The first element represents the most preferred language.
+
+If your application supports multiple languages and you want to display pages in the language that is the most preferred
+by the end user, you may use the language negotiation method [[yii\web\Request::getPreferredLanguage()]].
+This method takes a list of languages supported by your application, compares them with [[yii\web\Request::acceptableLanguages|acceptableLanguages]],
+and returns the most appropriate language.
+
+> Tip: You may also use the [[yii\filters\ContentNegotiator|ContentNegotiator]] filter to dynamically determine 
+  what content type and language should be used in the response. The filter implements the content negotiation
+  on top the properties and methods described above.
+
+
+## Client Information <a name="client-information"></a>
+
+You can get the host name and IP address of the client machine through [[yii\web\Request::userHost|userHost]]
+and [[yii\web\Request::userIP|userIP]], respectively. For example,
+
+```php
+$userHost = Yii::$app->request->userHost;
+$userIP = Yii::$app->request->userIP;
+```