UiState

UiState.kt

/*
 * 2021 Yuriy Timofeev <intelligence.worker@gmail.com>.
 */

sealed class UiState<out T> where T : Any? {

    object Loading : UiState<Nothing>()

    data class Success<T>(val data: T) : UiState<T>()

    data class Error(val message: String, val error: Throwable) : UiState<Nothing>()

    fun fold(
        onLoading: () -> Unit,
        onSuccess: (T) -> Unit,
        onError: (Error) -> Unit
    ) {
        when (this) {
            Loading -> onLoading.invoke()
            is Success -> onSuccess(this.data)
            is Error -> onError(this)
        }
    }
}

infix fun <T> UiState<T>.takeIfSuccess(onSuccess: T.() -> Unit): UiState<T> {
    return when (this) {
        is UiState.Success -> {
            onSuccess(this.data)
            this
        }
        else -> {
            this
        }
    }
}

infix fun <T> UiState<T>.takeIfError(onError: UiState.Error.() -> Unit): UiState<T> {
    return when (this) {
        is UiState.Error -> {
            onError(this)
            this
        }
        else -> {
            this
        }
    }
}