Result Type Goodies

ResultType.swift

import RxSwift
import RxCocoa

enum Result<T>: ResultType {
    case success(T)
    case failure(Error)
    
    var data: T? {
        switch self {
        case .success(let d):
            return d
        default:
            return nil
        }
    }
    
    var error: Error? {
        switch self {
        case .failure(let e):
            return e
        default:
            return nil
        }
    }
}

protocol ResultType {
    associatedtype T
    var data: T? {get}
    var error: Error? {get}
}

extension ObservableType where E: ResultType  {
    func filterSuccess() -> Observable<E.T> {
        return flatMap { result -> Observable<E.T> in
            if let data = result.data {
                return Observable.just(data)
            }
            return Observable.empty()
        }
    }
}

extension ObservableType where E: ResultType  {
    func filterFailure() -> Observable<Error> {
        return flatMap { result -> Observable<Error> in
            if let error = result.error {
                return Observable.just((error))
            }
            return Observable.empty()
        }
    }
}

extension ObservableType {
    func driveResult() -> Driver<Result<E>> {
        return self.map { Result.success($0) }
            .asDriver(onErrorRecover: { Driver.just(.failure($0)) })
    }
}