开源软件名称（OpenSource Name）：

orbit-mvi/orbit-mvi

开源软件地址(OpenSource Url)：

https://github.com/orbit-mvi/orbit-mvi

开源编程语言(OpenSource Language)：

Kotlin 97.8%

开源软件介绍(OpenSource Introduction)：

Orbit Multiplatform

Get in touch

What is Orbit

Orbit is a Redux/MVI-like library - but without the baggage. It's so simple we think of it as MVVM+.

Simple, type-safe, coroutine-style, extensible API
Multiplatform, targetting Android and iOS (iOS support is in alpha and being actively worked on)
Full support for Kotlin Coroutines (it's built on top of them after all)
Lifecycle-safe collection of infinite flows
ViewModel support, along with SavedState
Optional, simple unit test library
Built-in espresso idling resource support
Compatible with RxJava, LiveData etc. through coroutine wrappers
And more...

Documentation

Articles & Talks

Getting started

implementation("org.orbit-mvi:orbit-core:<latest-version>")
// or, if on Android:
implementation("org.orbit-mvi:orbit-viewmodel:<latest-version>")

// Tests
testImplementation("org.orbit-mvi:orbit-test:<latest-version>")

Define the contract

data class CalculatorState(
    val total: Int = 0
)

sealed class CalculatorSideEffect {
    data class Toast(val text: String) : CalculatorSideEffect()
}

Create the ViewModel

Implement the ContainerHost interface
Override the container field and use the ViewModel.container factory function to build an Orbit Container in your ContainerHost

class CalculatorViewModel: ContainerHost<CalculatorState, CalculatorSideEffect>, ViewModel() {

    // Include `orbit-viewmodel` for the factory function
    override val container = container<CalculatorState, CalculatorSideEffect>(CalculatorState())

    fun add(number: Int) = intent {
        postSideEffect(CalculatorSideEffect.Toast("Adding $number to ${state.total}!"))

        reduce {
            state.copy(total = state.total + number)
        }
    }
}

We have used an Android ViewModel as the most common example, but there is no requirement to do so.

Connect to the ViewModel in your Activity or Fragment

class CalculatorActivity: AppCompatActivity() {

    // Example of injection using koin, your DI system might differ
    private val viewModel by viewModel<CalculatorViewModel>()

    override fun onCreate(savedState: Bundle?) {
        ...

        addButton.setOnClickListener { viewModel.add(1234) }

        viewModel.observe(state = ::render, sideEffect = ::handleSideEffect)
    }

    private fun render(state: CalculatorState) {
        ...
    }

    private fun handleSideEffect(sideEffect: CalculatorSideEffect) {
        when (sideEffect) {
            is CalculatorSideEffect.Toast -> toast(sideEffect.text)
        }
    }
}

With Jetpack Compose wire up the ViewModel as follows:

@Composable
fun CalculatorScreen(viewModel: CalculatorViewModel) {

    val state = viewModel.collectAsState().value

    viewModel.collectSideEffect { handleSideEffect(it) }

    // render UI using data from 'state'
    ...
}

private fun handleSideEffect(sideEffect: CalculatorSideEffect) {
    when (sideEffect) {
        is CalculatorSideEffect.Toast -> toast(sideEffect.text)
    }
}