Class yii\filters\ContentNegotiator

ContentNegotiator supports response format negotiation and application language negotiation.

When the supported formats property is specified, ContentNegotiator will support response format negotiation based on the value of the GET parameter $formatParam and the Accept HTTP header. If a match is found, the yii\web\Response::$format property will be set as the chosen format. The yii\web\Response::$acceptMimeType as well as yii\web\Response::$acceptParams will also be updated accordingly.

When the supported languages is specified, ContentNegotiator will support application language negotiation based on the value of the GET parameter $languageParam and the Accept-Language HTTP header. If a match is found, the yii\base\Application::$language property will be set as the chosen language.

You may use ContentNegotiator as a bootstrapping component as well as an action filter.

The following code shows how you can use ContentNegotiator as a bootstrapping component. Note that in this case, the content negotiation applies to the whole application.

// in application configuration
use yii\web\Response;

return [
    'bootstrap' => [
        [
            'class' => 'yii\filters\ContentNegotiator',
            'formats' => [
                'application/json' => Response::FORMAT_JSON,
                'application/xml' => Response::FORMAT_XML,
            ],
            'languages' => [
                'en',
                'de',
            ],
        ],
    ],
];

The following code shows how you can use ContentNegotiator as an action filter in either a controller or a module. In this case, the content negotiation result only applies to the corresponding controller or module, or even specific actions if you configure the only or except property of the filter.

use yii\web\Response;

public function behaviors()
{
    return [
        [
            'class' => 'yii\filters\ContentNegotiator',
            'only' => ['view', 'index'],  // in a controller
            // if in a module, use the following IDs for user actions
            // 'only' => ['user/view', 'user/index']
            'formats' => [
                'application/json' => Response::FORMAT_JSON,
            ],
            'languages' => [
                'en',
                'de',
            ],
        ],
    ];
}