playframework Dependency Injection - Scala Injecting Play classes

Example

You will often need to access instances of classes from the framework itself (like the WSClient, or the Configuration). You can inject them in your own classes :

class ComplexService @Inject()(
  configuration: Configuration,
  wsClient: WSClient,
  applicationLifecycle: ApplicationLifecycle,
  cacheApi: CacheApi,
  actorSystem: ActorSystem,
  executionContext: ExecutionContext
  ) {
  // Implementation goes here
  // you can use all the injected classes :
  //
  // configuration to read your .conf files
  // wsClient to make HTTP requests
  // applicationLifecycle to register stuff to do when the app shutdowns
  // cacheApi to use a cache system
  // actorSystem to use AKKA
  // executionContext to work with Futures
}

Some, like the ExecutionContext, will likely more easy to use if they're imported as implicit. Just add them in a second parameter list in the constructor :

class ComplexService @Inject()(
  configuration: Configuration,
  wsClient: WSClient
  )(implicit executionContext: ExecutionContext) {
  // Implementation goes here
  // you can still use the injected classes
  // and executionContext is imported as an implicit argument for the whole class
}