Scala dependency injection simple pattern - scala

Question

I hope you are having a great day!
By the requirement of the framework, I have to use inject Configuration class and in order to get configuration keys.
The problem is now I have to refactor my code but I can't figure out how can I do that.
Problem
For the sake of simplicity let's consider a Sender class and it's companion object.
class Sender(image: File, name: String) {
def send() = { Sender.s3Client.send(image, name) }
}
object Sender {
val accessKey = config.get[String]("accessKey")
val secretKey = config.get[String]("secretKey")
val s3Client: AmazonS3 = ... withCredentials ( accessKey, secretKey) ...
}
Here I config.get method should be an injected object.
Question
How can I inject Configuration class in this scenario?
I can't use like below because Some other method instantiates this class with image and name param
class Sender #Inject() (image: File, name: String, config: Configuration) { ... }
Thank you!

Answer 1

In Scala, you can have your own DI container even without using DI Framework.
trait ConfigurationModule {
def config: Configuration
}
trait S3Module {
def accessKey: String
def secretKey: String
lazy val s3Client: AmazonS3 = ... withCredentials ( accessKey, secretKey) ...
}
object YourOwnApplicationContext extends ConfigurationModule with S3Module with ... {
...
lazy config: Configuration = ConfigFactory.load()
lazy val accessKey = config.get[String]("accessKey")
lazy val secretKey = config.get[String]("secretKey")
}
Now all your dependencies are in YourOwnApplicationContext.
So you can do this:
class Sender(image: File, name: String) {
def send() = YourOwnApplicationContext.s3Client.send(image, name)
}
You may read these articles:
MacWire
Dependency Injection in Scala using MacWire