com.sefford.kor.usecases.StandaloneUseCase.kt Maven / Gradle / Ivy
/*
* Copyright (C) 2018 Saúl Díaz
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.sefford.kor.usecases
import arrow.core.Either
import com.sefford.common.interfaces.Postable
import com.sefford.kor.usecases.components.BackgroundPool
import com.sefford.kor.usecases.components.Error
import com.sefford.kor.usecases.components.Response
import kotlinx.coroutines.experimental.launch
import kotlin.coroutines.experimental.CoroutineContext
/**
* Standalone use case that allows individual execution of a Single use case
*
* @author Saul Diaz
*/
interface StandaloneUseCase {
/**
* Instantiates the internal use case for execution.
*
* This is executed ad-hoc when any of the execution methods are invoked, so
* the use case is instantiated and it does not retain state.
*
* @param params Parameter configuration of the use case
*/
fun instantiate(params: P): UseCase
/**
* Executes the use case syncronously.
*
* @param params Parameter configuration of the use case
*/
fun execute(params: P): Either = instantiate(params).execute()
/**
* Executes the use case depending on a coroutine context and outputs the
* results via a {@link Postable Postable} element.
*
* @param thread Execution context of the use case
* @postable Postable element where to output the results
* @param params Parameter configuration of the use case
*/
fun execute(thread: CoroutineContext = BackgroundPool, postable: Postable, params: P) = launch(thread) {
execute(params).fold({ postable.post(it) }, { postable.post(it) })
}
/**
* Executes the use case depending on an asynchoronous context context and outputs the
* results via a {@link Postable Postable} element.
*
* @postable Postable element where to output the results
* @param params Parameter configuration of the use case
*/
fun async(postable: Postable, params: P) = execute(BackgroundPool, postable, params)
/**
* Executes the use case depending on a coroutine context and outputs the
* results.
*
* @param thread Execution context of the use case
* @param params Parameter configuration of the use case
*/
suspend fun async(params: P): Either = kotlinx.coroutines.experimental.async(BackgroundPool) {
instantiate(params).execute()
}.await()
}