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Getting Started

# Getting Started

The Compose examples below use the 3.0.0 API. When upgrading from a published version, follow the migration guide.

Install The Right Module

Start with the base module:

dependencies {
    implementation("io.github.matheus-corregiari:event-observer:<version>")
}

Add the Compose module when your rendering layer is Compose Multiplatform:

dependencies {
    implementation("io.github.matheus-corregiari:event-observer-compose:<version>")
}

For saved Repository-to-ViewModel state in commonMain, add:

kotlin {
    sourceSets.commonMain.dependencies {
        implementation("io.github.matheus-corregiari:event-observer-state:<version>")
    }
}

Use saveState for plain values or saveResponseState for results. See the state guide for a complete ViewModel example and serialization setup.

See the dedicated module pages for the split:

Create A Result

DataResult<T> is the core model. Use the helpers to build the state you need.

val loading = dataResultLoading<String>()
val success = dataResultSuccess("Loaded")
val error = dataResultError<String>(RuntimeException("Boom"))
val none = dataResultNone<String>()

Observe It In LiveData

ResponseLiveData<T> lets you emit DataResult values from coroutine code and observe them from Android UI.

val userLiveData = responseLiveData<String> {
    emitLoading()
    emitData("Hello")
}

userLiveData.observe(this) {
    loading { isLoading -> println("loading=$isLoading") }
    data { value -> println(value) }
    error { throwable -> println(throwable.message) }
}

Render It In Compose

Add event-observer-compose, then render a Flow<DataResult<T>> using Content. For a static DataResult<T>, use Content or DataResultContent.

myFlow.Content {
    OnShowLoading { CircularProgressIndicator() }
    OnData { value -> Text(value.toString()) }
    OnError { error -> Text(error.message ?: "Unknown error") }
}
  • Read the module pages to choose the right dependency surface.
  • Read Core Concepts to understand the state model.
  • Use Recipes for common patterns.
  • Check API Reference for per-module API docs.
  • Check Changelog when you need release history.