LightIoC

A light-weight Inversion of Control (IoC) tools by Dependency Injection (DI) for Scala.

Using library

This library is complied for Scala 2.13.x, 2.12.x, 2.11.x, and also tested in Java8, 11, 16.

SBT:

libraryDependencies += "space.controlnet" %% "lightioc" % "0.3.2"

Gradle:

implementation group: "space.controlnet", name: "lightioc_<scala_version>", version: "0.3.2"

A Java-friendly API compiled by Scala 2.13 is provided. See Java-Friendly API. Gradle:

implementation group: "space.controlnet", name: "lightioc-api", version: "0.3.2"

Quick start

Static registry

import space.controlnet.lightioc.Container

@Provider 
class TopLevelClass

@Singleton
class TopLevelSingletonClass

@Provider(isObject = true)
object TopLevelObject

@Provider(stringId = "IdForThisClass")
class NamedProviderClass

@Provider(isObject = true)
object NestedClass {

  @Provider
  class InnerClass

  @Provider(isObject = true)
  object InnerObject
}

object Main extends App {
  Container.init("<package name>")
}

Dynamic registry

import space.controlnet.lightioc.Container
import space.controlnet.lightioc.Util._

class Foo
class Bar {
  var x: Int = _
  var y: Int = _
}
object Baz
class Qux(foo: Foo)

object Main extends App {
  // register Foo to self constructor in Transient scope
  Container.register[Foo].toSelf.inTransientScope()
  // register Bar to self constructor in Singleton scope
  Container.register[Bar].toSelf.inSingletonScope()
  // register Baz as well
  Container.register[Baz.type].toSelf.inSingletonScope()
  // register a constructor with parameters
  Container.register[Qux].toConstructor(classOf[Foo]).inTransientScope()
  // register a constant value
  Container.register("A Number").toValue(123).inSingletonScope()
  // register a factory
  val barX = 1
  val barY = 2
  Container.register[Int]("Bar.x").toValue(barX).inSingletonScope()
  Container.register[Int]("Bar.y").toValue(barY).inSingletonScope()
  val factory: Factory[Bar] = Container => {
    // do anything you want
    val bar = new Bar
    bar.x = Container.resolve[Int]("Bar.x")
    bar.y = Container.resolve[Int]("Bar.y")
    bar
  }
  Container.register[Bar].toFactory(factory).inTransientScope()
  // register to another service (registry)
  Container.register[Foo].toSelf.inTransientScope() // target service
  Container.register("AnotherFoo").toService[Foo]
}

Of course, if you prefer to use operators...

import space.controlnet.lightioc.Container
import space.controlnet.lightioc.BindingSetter.{ New, Self }

object Main extends App {
  // register to value in Transient
  Container.register("AString") -> "Hello IOC"
  // register to constructor/class in Transient
  Container.register[Foo] -> classOf[Foo]
  // register to constructor/class in Singleton
  Container.register[Bar] := classOf[Bar]
  // register to self
  Container.register[Baz.type] -> Self
  // register to a constructor with parameters
  Container.register[Qux] -> New(classOf[Foo])
  // register to factory
  Container.register[Bar] ~> factory
  // register to service
  Container.register("AnotherString") >> "AString"
}

Dynamic resolve

import space.controlnet.lightioc.Container

object Main extends App {
  // resolve by type
  val foo: Foo = Container.resolve[Foo]
  // resolve by string
  val str: String = Container.resolve[String]("AString")
  // resolve by factory
  val bar: Bar = Container.resolve[Bar]
}

Autowire

import space.controlnet.lightioc.annotation.{ Autowired, Provider }

@Provider
class Foo {
  @Autowired
  val bar: Bar = null
}

@Provider
class Bar

@Provider
object Baz {
  @Autowired
  var x: Int = 0 // should be "var"
}

Java-Friendly API

Gradle:

implementation group: "space.controlnet", name: "lightioc-api", version: "0.3.2"

Kotlin Example

import space.controlnet.lightioc.annotation.Singleton
import space.controlnet.lightioc.api.Container

@Singleton
class A {
    val x: Int = 100
}

fun main() {
    Container.init("<package name>")
    val a = Container.resolve(A::class.java)
    println(a.x)
}

Acknowledges

dylech30th/simple-ioc: A kotlin based IoC container implementation.
inversify/InversifyJS: A powerful and lightweight IoC container for JS apps powered by TypeScript.

controlnet / lightioc 0.3.2