在示例播放剪影模板中定义隐式环境值（使用Guice）

Question

In the silhouette implementation example found here , how in the template is the implicit 'env' value (of type Environment[User, CachedCookieAuthenticator]) used in line 28 of /app/controllers/SignUpController.scala, for example, defined using Guice?

I guess I do not understand how provideEnvironment in app/utils/di/SilhouetteModule.scala is used to "inject" the Silhouette Enviroment into SignUpController (for example) via the "injector" created in line 24 of app/Global.scala. I don't see provideEnvironment being used anywhere in the play-silhouette-slick-seed example, so I can't seem to figure out what values are given to its arguments (such as userService, authenticatorService etc).

Answer 1

This example of silhouette module use Guice for scala Dependency Injection framework. All bindings are configured in util.di.SilhouetteModule.scala file. There is another example where Dependency Injection is replaced by Cake pattern. look at this

[edited]In short:

If you look at the Global.scala file, you'll find the guice configuration. Guice is forced to create every controller. Every view is dependend on controllers and will be managed by guice too.

The SilhouetteModule.scala file, as was mentioned above, is for configuration Silhouette module. There are few methods annotated with @Provides . If you look at the Guice documentation . Such method is called by Guice every time it needs class type the method returns, for instance: each time guice need to inject Environment[User, CachedCookieAuthenticator] it call def provideEnvironment method because this method return such type.