Modules with @Module

While using definitions, you may need to organize them in modules or not. You can even not use any module at all and use the "default" generated module.

No Module - Using the Generated Default Module

If you don't want to specify any module, Koin provide a default one to host all your definitions. The defaultModule is ready to be use directly:

// Use Koin Generation
import org.koin.ksp.generated.*

fun main() {
    startKoin {
        defaultModule()
    }
}

// or 

fun main() {
    startKoin {
        modules(
          defaultModule
        )
    }
}

info

Don't forget to use the org.koin.ksp.generated.* import

Class Module with @Module

To declare a module, just tag a class with @Module annotation:

@Module
class MyModule

To load your module in Koin, just use the .module extension generated for any @Module class. Just create new instance of your module MyModule().module:

// Use Koin Generation
import org.koin.ksp.generated.*

fun main() {
    startKoin {
        modules(
          MyModule().module
        )
    }
}

Don't forget to use the org.koin.ksp.generated.* import

Components Scan with @ComponentScan

To scan and gather annotated components into a module, just use the @ComponentScan annotation on a module:

@Module
@ComponentScan
class MyModule

This will scan current package and subpackages for annotated components. You can specify to scan a given package @ComponentScan("com.my.package")

info

When using @ComponentScan annotation, KSP traverses accross all Gradle modules for the same package. (since 1.4)

Definitions in Class Modules

To define a definition directly in your can, you an annotate a function with definition annotations:

// given 
// class MyComponent(val myDependency : MyDependency)

@Module
class MyModule {

  @Single
  fun myComponent(myDependency : MyDependency) = MyComponent(myDependency)
}

@InjectedParam, @Property are also usable on function members

Including Modules

To include other class modules to your module, just use the includes attribute of the @Module annotation:

@Module
class ModuleA

@Module(includes = [ModuleA::class])
class ModuleB

This way you can just run your root module:

// Use Koin Generation
import org.koin.ksp.generated.*

fun main() {
    startKoin {
        modules(
          // will load ModuleB & ModuleA
          ModuleB().module
        )
    }
}