ApiUtils.kt

ApiService.kt

import io.reactivex.Single
import retrofit2.Response
import retrofit2.http.GET
import retrofit2.http.Query

interface ApiService {

    @GET("Controller/action")
    fun apiCallName(
        @Query("param") param: Long
    ): Single<Response<ApiResponseType>>

}

ApiUtils.kt

fun <T> Single<Response<T>>.getResponseOrError(): Single<T> {
    return flatMap {
        if (it.isSuccessful && (it.body() != null) && (it.errorBody() == null)) {
            Single.create<T> { e -> e.onSuccess(it.body()!!) }
        } else {
            Single.create<T> { e -> e.onError(ApiRequestFailedException(it.headers()[REASON_MESSAGE_KEY] ?: "")) }
        }
    }
}


fun <T> Single<Response<T>>.getCompletableOrError(): Completable {
    return flatMapCompletable {
        if (it.isSuccessful && (it.errorBody() == null)) {
            if (it.body() is Boolean) {
                if (it.body() as Boolean) {
                    Completable.complete()
                } else {
                    Completable.error(ApiRequestFailedException(it.headers()[REASON_MESSAGE_KEY] ?: ""))
                }
            } else {
                Completable.complete()
            }
        } else {
            Completable.error(ApiRequestFailedException(it.headers()[REASON_MESSAGE_KEY] ?: ""))
        }
    }
}

Repository.kt

class Repository {

  fun getData(): Single<ApiResponseType> {
    return apiService.apiCallName().getResponseOrError()
  }

}