Does Koin provide the functionality of binding several dependencies into a collection, as Dagger does with multibindings?
Let's suppose I have this interface:
interface Initializer: (Application) -> Unit
And this interface has several implementations, for instance:
class LoggingInitializer: Initializer {
override fun invoke(p1: Application) {
Timber.plant(Timber.DebugTree())
}
}
The implementations are provided in different modules using bind modifier:
val coreToolsModules = module {
single { LoggingInitializer() } bind Initializer::class
}
And such modules are installed in the app's Application class:
class TestApplication: Application() {
override fun onCreate() {
super.onCreate()
val startKoin = startKoin {
logger(PrintLogger())
androidContext(this#TestApplication)
modules(listOf(coreToolsModules))
}
}
}
I'd like to inject all implementations of Initializer class as a set to my Application class in order to carry out such initialization:
val initializers: Set<Initializer> by inject()
//in onCreate()
initializers.forEach { it.invoke(this) }
Related
I am developing an Android application using Kotlin. I am writing integration tests for my application. Now I am having a problem mocking an injected dependency class that is injected using the Dagger 2 test if a method of the mocked object is called. Following is my code.
I have the TestAppComponent class with the following code
#Singleton
#Component(modules = [ TestAppModule::class ])
interface TestAppComponent
{
fun inject(app: ApplicationController)
fun inject(app: MockApplicationController)
}
As you can see in the class, I have two inject methods. One for the ApplicationController which basically is the application class used for the actual application. Another one for MockAppllication controller which is also the application class but it is used for the tests.
Following is the implementation of the ApplicationController class
open class ApplicationController: Application()
{
lateinit var appComponent: AppComponent
private fun initDagger(app: ApplicationController): AppComponent = DaggerAppComponent
.builder()
.appModule(AppModule(app)).build()
#Inject
lateinit var fileService: IFileService
override fun onCreate() {
super.onCreate()
appComponent = initDagger(this)
instance = this
this.appComponent.inject(this)
}
}
As you can see in the code, I am initializing the Dagger AppComponent class in the onCreate method of the application class. Then inject the dependency class.
This is the implementation of my MockApplicationController class which is used for the tests.
class MockApplicationController: ApplicationController()
{
private fun initDagger(app: MockApplicationController): AppComponent = DaggerTestAppComponent
.builder()
.testAppModule(TestAppModule(app))
.build()
override fun onCreate() {
super.onCreate()
//override the dagger app component appComponent
this.appComponent = initDagger(this)
instance = this
this.appComponent.inject(this)
}
}
This is my activity class.
class MainActivity: AppCompatActivity()
{
override fun onCreate(savedInstanceState: Bundle?) {
//rest of the code
button_save_file.setOnClickListener {
//rest of the code
ApplicationController.instance.fileService.saveFile(filePath)
}
}
}
As you can see, basically, what I am doing within the activity class is that I am just calling the saveFile of the IFileService interface.
Following is the definition of the IFileService interface
interface IFileService
{
fun saveFile(path: String)
}
There are two classes that are implementing the IFileService. One is FakeFileService class which will be used for the tests and the other one is FileService class which will be used for the actual application.
Following is the implementation of FakeFileService class
class FakeFileService: IFileService
{
fun saveFile(path: String)
{
//literally, this is doing nothing since we will only test that if the method is called
}
}
I also created two classes for the Dagger app modules. One for the tests and the other one for the actual application.
Following is the implementation of the TestAppModule class which will be used for tests.
#Module
open class TestAppModule (private val app: Application) {
private var fileService: IFileService? = null
#Singleton
#Provides
fun provideContext(): Context = app
//to override injecting the Mockito mock instance
fun injectFileService(fileService: IFileService) {
this.fileService = fileService
}
#Singleton
#Provides
open fun fileService(): IFileService {
if (this.fileService != null) {
return this.fileService as IFileService
}
return FakeFileService()
}
}
Note the injectFileService method. I created that method to inject the mock object/ instance mocked using Mockito within the tests.
This is my test class
#RunWith(AndroidJUnit4::class)
#LargeTest
class CameraTest: TestBuilder()
{
#get:Rule
var mainActivityRule: ActivityTestRule<MainActivity> = ActivityTestRule<MainActivity>(CameraActivity::class.java, true, false)
private lateinit var fileServiceMock: IFileIOService
#Before
fun setUp() {
this.fileServiceMock = mock(IFileService::class.java)
MockitoAnnotations.initMocks(this)
val instrumentation = InstrumentationRegistry.getInstrumentation()
val app = instrumentation.targetContext.applicationContext as MockApplicationController
var testModule = TestAppModule(app)
testModule.injectFileService(this.fileServiceMock)
app.appComponent = DaggerTestAppComponent
.builder()
.testAppModule(testModule)
.build()
app.appComponent.inject(app)
}
#Test
fun itSavesFileWhenButtonIsClicked() {
Intents.init()
var targetContext: Context = InstrumentationRegistry.getInstrumentation().targetContext
var intent: Intent = Intent(targetContext, MainActivity::class.java)
this.mainActivityRule.launchActivity(intent)
onView(withId(R.id.button_save_file)).perform(click())
verify(this.fileServiceMock).saveFile(any())
Intents.release()
}
}
As you can see, in my test class, I try to inject the mocked version of IFileService object before the test is run. Then in my test, I am asserting that the method is executed. When I run the test it is complaining that "zero interactions with this mock". How can I fix it? What is wrong with my code and how can I fix it?
This is my ApplicationController class
open class ApplicationController: Application()
{
lateinit var appComponent: AppComponent
private fun initDagger(app: ApplicationController): AppComponent = DaggerAppComponent
.builder()
.appModule(AppModule(app)).build()
#Inject
lateinit var fileService: IFileService
override fun onCreate() {
super.onCreate()
appComponent = initDagger(this)
instance = this
this.appComponent.inject(this)
}
}
When I put the loggin in each onCreate method of application controller classes and #Before method, they are called in the following order.
ApplicationController
MockApplicationController
The code to modify the MockApplicationController with the #Before method
I would like to define 2 injected classes, but one needs to use the second class method for the constructor. I am using Koin framework
class MainActivity : AppCompatActivity() {
private val connectionService : ConnectionService by inject()
private val resourcesHelper : ResourcesHelper by inject()
private val addressPropertyName = "connection.address"
private val portPropertyName = "connection.port"
private val appModule = module {
single { ResourcesHelperImpl(androidContext(), R.raw.config) }
single {
ConnectionServiceTcp(
resourcesHelper.getConfigValueAsString(addressPropertyName),
resourcesHelper.getConfigValueAsInt(portPropertyName)
)
}
}
And then I get an error because I cannot instantiate ConnectionServiceTcp using resourcesHelper. Is there a way to use injected field to inject another field?
Edit
Changing to get() helped, but now I struggle with module configuration.
I moved start koin to MainApplication class:
class MainApplication : Application() {
override fun onCreate() {
super.onCreate()
startKoin {
androidContext(this#MainApplication)
androidLogger()
modules(appModule)
}
}
}
And module to AppModule.kt
val appModule = module {
single { ResourcesHelperImpl(androidContext(), R.raw.drone) }
single {
ConnectionServiceTcp(
get<ResourcesHelper>().getConfigValueAsString(ResourcesHelper.droneAddressPropertyName),
get<ResourcesHelper>().getConfigValueAsInt(ResourcesHelper.dronePortPropertyName)
)
}
scope(named<MainActivity>()) {
scoped {
ConnectionServiceTcp(get(), get())
}
}
}
And then I try to inject some object to activities and I am getting
Caused by: org.koin.core.error.NoBeanDefFoundException: No definition found for has been found. Check your module definitions.
Okay, I encountered two problems, firstly I could not instantiate bean using other bean in constructor, it was resolved by changing my invoke to
ConnectionServiceTcp(
get<ResourcesHelper>().getConfigValueAsString(ResourcesHelper.droneAddressPropertyName),
get<ResourcesHelper>().getConfigValueAsInt(ResourcesHelper.dronePortPropertyName)
)
Secondly, there was a problem with NoBeanDefFoundException, it was due androidContext() in ResourcesHelperImpl, I needed there Context from the activity, not the koin context.
I'm trying to learn Koin for dependency injection in android. I started to follow the example and try to inject very simple object by but I'm getting the error as NoBeanDefFoundException: No definition found for ...
here's my code
Gradle
// Koin
def koin_version = '2.0.1'
implementation "org.koin:koin-androidx-scope:$koin_version"
implementation "org.koin:koin-androidx-viewmodel:$koin_version"
implementation "org.koin:koin-androidx-ext:$koin_version"
Application onCreate()
override fun onCreate() {
super.onCreate()
startKoin{
androidLogger()
androidContext(this#Application)
listOf(applicationModule)
}
}
Modules.kt
val applicationModule = module {
factory { UserSession("email","password") }
}
but when I try to inject it in anywhere (Application, Activity, Fragment) as private val userSession: UserSession by inject() I get above mentioned error. Am I missing something?
You probably got confused by the syntax, you're supposed to call the method modules and provide it with the modules you want started.
The listOf return value is ignored in your case, you're supposed to do something like this:
startKoin {
androidLogger()
androidContext(this#Application)
modules(applicationModule)
}
Reference
try this.
KoinApp.kt
class KoinApp : MultiDexApplication() {
override fun onCreate() {
super.onCreate()
startKoin(this, listOf(appModule))
}
}
appModule.kt
#JvmField
val appModule = module {
single { DataRepository(get()) }
}
The answer will work, but for future proofing, I would still have the list of.
startKoin {
androidLogger()
androidContext(this#Application)
modules(listOf(applicationModule))
}
Modules.kt:
val appModule = module {
single { MyRepositoryImpl() }
}
val viewModelModule = module {
viewModel { MainViewModel(get()) }
}
MyApp.kt:
class MyApp : Application() {
override fun onCreate() {
super.onCreate()
startKoin {
androidContext(this#MyApp)
modules(listOf(appModule, viewModelModule))
}
}
}
Go to AndroidManifest and add:
<application
android:name=".MyApp"
...
</application>
MainActivity.kt:
//ViewModel
private val vm:MainViewModel = get()
I'm new at Koin. I have set all the stuff and is working. But I'm getting some problems when I'm trying to inject interactor and presenter at the same time. That not sure it is possible.
This is my Module
val applicationModule = module(override = true) {
factory{VoucherImpl(get())}
factory<VoucherContract.Presenter> { (view: VoucherContract.View) -> VoucherPresenter(view, get()) }
}
This is my Activity where inject the presenter
private val presenter: VoucherContract.Presenter by inject { parametersOf(this)}
This is my Presenter
class VoucherPresenter (private var view: VoucherContract.View?, private var mCodeRechargeInteract : VoucherImpl) : VoucherContract.Presenter, VoucherContract.Callback, KoinComponent {
override fun create() {
view?.initView()
view?.showProgress()
mCodeRechargeInteract.run()
}
.
.
.
Interactor class
class VoucherImpl(private var mCallback: VoucherContract.Callback?) : AbstractInteractor() {
.
.
.
contract
interface VoucherContract {
interface Presenter {
fun create()
fun destroy()
fun checkIfShoppingCartHaveItems()
fun addVoucherToShoppingCart(voucherProduct: Product)
fun onItemClick(product: Product)
}
interface Callback {
fun onResponseVouchers(vouchers: List<Product>?)
fun onError()
}
}
With this code I get
No definition found for 'xxx.voucher.VoucherContract$Callback' has been found. Check your module definitions.
Then, I try to put it in the module and I can't do it because I get: a Type mismatch. Required VoucherContract.Callback Found VoucherImpl
factory<VoucherContract.Callback> { (callBack: VoucherContract.Callback) -> VoucherImpl(callBack) }
You have a circular dependency that's why this doesn't work.
VoucherImpl(VoucherContract.Callback) and VoucherPresenter(View, VoucherImpl):VoucherContract.Callback
There are multiple ways out of this predicament.
I would recommend the following changes:
The VoucherImpl should not have the constructor parameter VoucherContract.Callback. This callback should be the parameter of a method something like this:
class VoucherImpl : AbstractInteractor(){
fun listen(VoucherContract.Callback){...}
}
This way the dependency becomes one way and you can inject them.
There are two modules in my android project, app module and lib module.
Both these two modules need Koin for D.I., so I call startKoin in MyApplication class in app module, and IninKointContentProvider in lib module as below.
// app module
class MyApplication : Application() {
override fun onCreate() {
super.onCreate()
startKoin(this, modules1)
}
}
// lib module
class InitKoinContentProvider : ContentProvider() {
override fun onCreate(): Boolean {
startKoin(context.applicationContext, modules2)
return true
}
}
Then app crashed and shown this message
Caused by: org.koin.error.BeanOverrideException: Try to override definition with Single [class='android.content.Context'], but override is not allowed. Use 'override' option in your definition or module.
I guess startKoin can be called only one time.
The solution I found is merging two koin modules then calling startKoin in MyApplication, but I don't like it. Lib module may be imported by other android project which doesn't use koin, in that case, I think calling startKoin in InitKoinContentProvider is better.
Any solution for this problem?? Thanks!
I found the best solution inspired by #laalto's answer, thanks!
Upgrade to koin 2.0, then use KoinApplication and customized KoinComponent to create a isolated koin context, it can let lib module using koin without any initializing call by app module, still start koin in ContentProvider. The whole code may like below.
// app module
class MyApplication : Application() {
override fun onCreate() {
super.onCreate()
startKoin {
androidContext(this#MyApplication)
modules(module{
viewModel { MainViewModel() }
})
}
}
}
class MainActivity: AppCompactActivity() {
private val viewModel: MainViewModel by viewModel()
}
// lib module
internal object MyKoinContext {
lateinit var koinApplication: KoinApplication
}
interface MyKoinComponent : KoinComponent {
override fun getKoin(): Koin {
return MyKoinContext.koinApplication.koin
}
}
class InitKoinContentProvider : ContentProvider() {
override fun onCreate(): Boolean {
MyKoinContext.koinApplication = koinApplication {
androidContext(context.applicationContext)
modules(module{
viewModel { FooViewModel() }
})
}
return true
}
}
class FooActivity: AppCompactActivity(), MyKoinComponent {
private val viewModel: FooViewModel by viewModel()
}
Ref:
https://insert-koin.io/docs/2.0/documentation/reference/index.html#_koin_context_isolation
In your library modules, use loadKoinModules() to load the module-specific koin modules. Docs.
You need to have run startKoin() prior to that, so the init order with content providers can be a little tricky.
To init extra koin modules on other project modules and get no duplicate loading issues (e.g. pressing home, than coming back to the activity), go to your module declaration file:
val myModule = module {
single { MyRepository(get()) }
viewModel { MyViewModel(get()) }
}
private val loadKoinModules by lazy {
loadKoinModules(myModule)
}
fun inject() = loadKoinModules
Then on your view:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
inject()
}
TL;DR
Use single/factory methods with override param set to true when providing your dependencies that are overriding those provided by the modules loaded before.
single<Manager>(override = true) { TestManager() }
I have faced a similar issue when I tried to override one of the dependencies for UI test purposes.
When I setup in Application.onCreate():
startKoin {
module {
single { Printer() }
}
}
and then in before method of test:
loadKoinModules(module {
single<Printer> { TestPrinter() }
})
I get a Runtime exception during the test:
org.koin.core.error.DefinitionOverrideException: Already existing definition or try to override an existing one
And the solution is to show Koin that you are intentionally overriding that dependency by using override param of single function like that:
loadKoinModules(module {
single<Printer>(override = true) { TestPrinter() }
})
By design startKoin is meant to be called from the Application class. You can provide a parameter in the lib whether to call startKoin or not. But I doubt that including such things as Koin in libs is a good practice. What if an application already includes Koin, but of different version?
This way worked perfect for me:
#KoinExperimentalAPI
class MainApplication : Application() {
override fun onCreate() {
super.onCreate()
initKoin()
}
private fun initKoin() {
startKoin {
androidLogger()
androidContext(this#MainApplication)
}
loadKoinModules(
myFeatureModule
)
}
}
And define you module in your feature as usual:
val myFeatureModule = module {
factory<...> { ...() }
single { ...() }
viewModel { ...(get() }
}