Simple RxSwift API Call

rx.swift

func getTodos() -> Observable<Any> {

        // If No Internet Connection Throws error
        // if Reachability()!.connection == .none {
        //     // !!!!  return data form cache here
        //     return Observable.error(RESTError(message: "No internet connection.", type: .warning))
        // }

        return Observable.create { (observer) -> Disposable in

            Alamofire.request("https://jsonplaceholder.typicode.com/todos", method: .get, parameters: nil, encoding: JSONEncoding.default, headers: ["Content-Type": "application/json"])
                .responseData { response in
                    switch response.result {
                    case let .success(data):
                        do {
                            observer.onNext(data)
                            observer.onCompleted()
                        } catch {
                            observer.onError(error)
                        }
                    case let .failure(error):
                        observer.onError(error)
                    }
                }

            return Disposables.create()
        }
}

Function call:

getTodos().subscribe({ [weak self] response in
                guard let self = self else {
                    return
                }
                 switch response {
                case let .next(data):
                    // data
                case let .error(error):
                   // error
                case .completed:
                    break
                }
            }).disposed(by: disposeBag)
    }