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This is an example of Android development with VIPER in Kotlin
interface LoginContracts {
interface View {
fun showError(message: String)
}
interface Presenter {
fun onDestroy()
fun onLoginButtonPressed(username: String, password: String)
}
interface Interactor {
fun unregister()
fun login(username: String, password: String)
}
interface InteractorOutput {
fun onLoginSuccess(user: User)
fun onLoginError(message: String)
}
interface Router {
fun unregister()
fun presentHomeScreen(user: User)
}
}
class LoginActivity: BaseActivity, LoginContracts.View {
var presenter: LoginContracts.Presenter? = null
//other fields
override fun onCreate() {
//...
presenter = LoginPresenter(this)
loginButton.setOnClickListener { onLoginButtonClicked() }
//...
}
override fun onDestroy() {
presenter?.onDestroy()
presenter = null
super.onDestroy()
}
private fun onLoginButtonClicked() {
presenter?.onLoginButtonClicked(usernameEditText.text, passwordEditText.text)
}
fun showError(message: String) {
//shows the error on a dialog
}
}
class LoginPresenter(var view: LoginContracts.View?): LoginContracts.Presenter, LoginContracts.InteractorOutput {
var interactor: LoginContracts.Interactor? = LoginInteractor(this)
var router: LoginContracts.Router? = LoginRouter(view as? Activity)
fun onDestroy() {
view = null
interactor?.unregister()
interactor = null
router?.unregister()
router = null
}
fun onLoginButtonPressed(username: String, password: String) {
interactor?.login(username, password)
}
fun onLoginSuccess(user: User) {
router?.goToNextScreen(user)
}
fun onLoginError(message: String) {
view?.showError(message)
}
}
class LoginInteractor(var output: LoginContracts.InteractorOutput?): LoginContracts.Interactor {
fun unregister() {
output = null
}
fun login(username: String, password: String) {
LoginApiManager.login(username, password)
?.subscribeOn(Schedulers.io())
?.observeOn(AndroidSchedulers.mainThread())
?.subscribe({
//does something with the user, like saving it or the token
output?.onLoginSuccess(it)
},
{ output?.onLoginError(it.message ?: "Error!") })
}
}
class LoginRouter(var activity: Activity?): LoginContracts.Router {
fun unregister() {
activity = null
}
fun presentHomeScreen(user: User) {
val intent = Intent(view, HomeActivity::class.java)
intent.putExtra(Constants.IntentExtras.USER, user)
activity?.startActivity(intent)
}
}
@MatteoPierro

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@MatteoPierro

MatteoPierro Oct 26, 2017

In this example the presenter doesn't survive to rotation, right?

In this example the presenter doesn't survive to rotation, right?

@Abdul-Moiz

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@Abdul-Moiz

Abdul-Moiz Feb 22, 2018

How much does it worth it now?
Given android have it's own view model architecture now.

How much does it worth it now?
Given android have it's own view model architecture now.

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