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Starting with Koin Annotations

The goal of Koin Annotations project is to help declare Koin definition in a very fast and intuitive way, and generate all underlying Koin DSL for you. The goal is to help developer experience to scale and go fast 🚀, thanks to Kotlin Compilers.

Getting Started​

Not familiar with Koin? First take a look at Koin Getting Started

Tag your components with definition & module annotations, and use the regular Koin API.

// Tag your component to declare a definition
@Single
class MyComponent
// Declare a module and scan for annotations
@Module
@ComponentScan
class MyModule

Use the org.koin.ksp.generated.* import as follow to be able to use generated code:

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

fun main() {
    val koin = startKoin {
        printLogger()
        modules(
          // use your modules here, with generated ".module" extension on Module classes
          MyModule().module
        )
    }

    // Just use your Koin API as regular
    koin.get<MyComponent>()
}

That's it, you can use your new definitions in Koin with the regular Koin API

KSP Options​

The Koin compiler offers some options to configure. Following the official doc, you can add the following options to your project: Ksp Quickstart Doc

Compile Safety - check your Koin config at compile time (since 1.3.0)​

Koin Annotations allows the compiler plugin to verify yout Koin configuration at compile time. This can be activated with the following Ksp options, to add to your Gradle module: 

// in build.gradle or build.gradle.kts

ksp {
    arg("KOIN_CONFIG_CHECK","true")
}

The compiler will check that all dependencies used in your configuration is declared, and all used modules are accessible.

Bypass Compile Safety with @Provided (since 1.4.0)​

Among the ignored type from Compiler (Android common types), the compiler plugin can verify your Koin configuration at compile time. If you want to exclude a parameter from being checked, you can use @Provided on a parameter to indicates that this type is provided externally to current Koin Annotations config.

The following indicates that MyProvidedComponent is already declared in Koin:

class MyProvidedComponent

@Factory
class MyPresenter(@Provided val provided : MyProvidedComponent)

Disabling Default Module (since 1.3.0)​

By default, the Koibn compiler detect any definition not bound to a module and put it in a "default mmodule", a Koin module generated at the root of your project. You can disable the use and generation of default module with the following option:

// in build.gradle or build.gradle.kts

ksp {
    arg("KOIN_DEFAULT_MODULE","false")
}

Kotlin KMP Setup​

Please follow KSP setup as described in official documentation: KSP with Kotlin Multiplatform

You can also check the Hello Koin KMP project with basic setup for Koin Annotations.