Error Handling in RxSwift

ViewController.swift

// MARK: Submit Button - action
viewModel.loggedIn.asObservable()
    .observeOn(MainScheduler.instance)
    .retryWhen { errorObservable -> Observable<Error> in
        errorObservable.map { [weak self] error in
            let alert = ErrorAlertBuilder(error: error).build()
            self?.present(alert, animated: true, completion: nil)
         
            return error
        }
    }
    .subscribe(onNext: { [weak self] in
        guard let strongSelf = self else { return }
        self?.dismiss(animated: true, completion: {
            self?.delegate?.didSignin(strongSelf)
        })
    })
    .addDisposableTo(disposeBag)