How to user an application behavior for maintain runtime configuration

In this tutorial will be explained a method forto manage some configuration runtime. [This excellent tutorial](http://www.yiiframework.com/wiki/26/setting-and-maintaining-the-language-in-application-i18n "") follows a similar approach, but requires to write a masterclass which all controllers are supposed to extend, following this wiki you can achieve the same by only editing only the configuration. This is often needed forto manage internationalization, themes and other confiugration that depends from the user. The most conmfortable way is to user an application behavior. In this example we save the language in the session, but it can also be saved in the database. Create a file in compomnents named ApplicationConfigBehavior and copy this code in it:

```php/**
* ApplicationConfigBehavior is a behavior for the application.
* It loads additional config paramenters that cannot be statically
* written in config/main
*//**
* Declares events and the event handler methods
* See yii documentation on behaviour
*/
public function events()ForTo update the language we can use a widget (to be included in layout/main), for example:


**components/LangBox.php**

```php