我有这个通用的 fetchData()我的 NetworkManager 类中的函数能够向网络发出授权请求，如果它失败(经过多次重试)会发出一个错误，该错误将重新启动我的应用程序(请求新的登录)。我需要同步调用这个重试 token ，我的意思是，如果多个请求失败，一次应该只有一个请求刷新 token 。如果一个失败，另一个请求必须被丢弃。我已经尝试了一些使用 DispatchGroup/NSRecursiveLock/以及调用描述波纹管的函数 cancelRequests 的方法(在这种情况下，任务计数始终为 0)。我怎样才能使这种行为在这种情况下起作用？
public func fetchData<Type: Decodable>(fromApi api: TargetType,
decodeFromKeyPath keyPath: String? = nil) -> Single<Response> {
let request = MultiTarget(api)
return provider.rx.request(request)
.asRetriableAuthenticated(target: request)
}
func cancelAllRequests(){
if #available(iOS 9.0, *) {
DefaultAlamofireManager
.sharedManager
.session
.getAllTasks { (tasks) in
tasks.forEach{ $0.cancel() }
}
} else {
DefaultAlamofireManager
.sharedManager
.session
.getTasksWithCompletionHandler { (sessionDataTask, uploadData, downloadData) in
sessionDataTask.forEach { $0.cancel() }
uploadData.forEach { $0.cancel() }
downloadData.forEach { $0.cancel() }
}
}
}
public extension PrimitiveSequence where TraitType == SingleTrait, ElementType == Response {
private var refreshTokenParameters: TokenParameters {
TokenParameters(clientId: "pdappclient",
grantType: "refresh_token",
refreshToken: KeychainManager.shared.refreshToken)
}
func retryWithToken(target: MultiTarget) -> Single<E> {
self.catchError { error -> Single<Response> in
if case Moya.MoyaError.statusCode(let response) = error {
if self.isTokenExpiredError(error) {
return Single.error(error)
} else {
return self.parseError(response: response)
}
}
return Single.error(error)
}
.retryToken(target: target)
.catchError { error -> Single<Response> in
if case Moya.MoyaError.statusCode(let response) = error {
return self.parseError(response: response)
}
return Single.error(InvalidGrantException())
}
}
private func retryToken(target: MultiTarget) -> Single<E> {
let maxRetries = 1
return self.retryWhen({ error in
error
.enumerated()
.flatMap { (attempt, error) -> Observable<Int> in
if attempt >= maxRetries {
return Observable.error(error)
}
if self.isTokenExpiredError(error) {
return Observable<Int>.just(attempt + 1)
}
return Observable.error(error)
}
.flatMap { _ -> Single<TokenResponse> in
self.refreshTokenRequest()
}
.share()
.asObservable()
})
}
private func refreshTokenRequest() -> Single<TokenResponse> {
return NetworkManager.shared.fetchData(fromApi: IdentityServerAPI
.token(parameters: self.refreshTokenParameters)).do(onSuccess: { tokenResponse in
KeychainManager.shared.accessToken = tokenResponse.accessToken
KeychainManager.shared.refreshToken = tokenResponse.refreshToken
}, onError: { error in
NetworkManager.shared.cancelAllRequests()
})
}
func parseError<E>(response: Response) -> Single<E> {
if response.statusCode == 401 {
// TODO
}
let decoder = JSONDecoder()
if let errors = try? response.map([BaseResponseError].self, atKeyPath: "errors", using: decoder,
failsOnEmptyData: true) {
return Single.error(BaseAPIErrorResponse(errors: errors))
}
return Single.error(APIError2.unknown)
}
func isTokenExpiredError(_ error: Error) -> Bool {
if let moyaError = error as? MoyaError {
switch moyaError {
case .statusCode(let response):
if response.statusCode != 401 {
return false
} else if response.data.count == 0 {
return true
}
default:
break
}
}
return false
}
func filterUnauthorized() -> Single<E> {
flatMap { (response) -> Single<E> in
if 200...299 ~= response.statusCode {
return Single.just(response)
} else if response.statusCode == 404 {
return Single.just(response)
} else {
return Single.error(MoyaError.statusCode(response))
}
}
}
func asRetriableAuthenticated(target: MultiTarget) -> Single<Element> {
filterUnauthorized()
.retryWithToken(target: target)
.filterStatusCode()
}
func filterStatusCode() -> Single<E> {
flatMap { (response) -> Single<E> in
if 200...299 ~= response.statusCode {
return Single.just(response)
} else {
return self.parseError(response: response)
}
}
}
}
最佳答案
这是一个 RxSwift 解决方案:RxSwift 和 Handling Invalid Tokens
仅仅发布链接并不是最好的，所以我也会发布解决方案的核心:
关键是要创建一个与 ActivityMonitor 类非常相似但处理 token 刷新的类...
public final class TokenAcquisitionService<T> {
/// responds with the current token immediatly and emits a new token whenver a new one is aquired. You can, for example, subscribe to it in order to save the token as it's updated.
public var token: Observable<T> {
return _token.asObservable()
}
public typealias GetToken = (T) -> Observable<(response: HTTPURLResponse, data: Data)>
/// Creates a `TokenAcquisitionService` object that will store the most recent authorization token acquired and will acquire new ones as needed.
///
/// - Parameters:
/// - initialToken: The token the service should start with. Provide a token from storage or an empty string (object represting a missing token) if one has not been aquired yet.
/// - getToken: A function responsable for aquiring new tokens when needed.
/// - extractToken: A function that can extract a token from the data returned by `getToken`.
public init(initialToken: T, getToken: @escaping GetToken, extractToken: @escaping (Data) throws -> T) {
relay
.flatMapFirst { getToken($0) }
.map { (urlResponse) -> T in
guard urlResponse.response.statusCode / 100 == 2 else { throw TokenAcquisitionError.refusedToken(response: urlResponse.response, data: urlResponse.data) }
return try extractToken(urlResponse.data)
}
.startWith(initialToken)
.subscribe(_token)
.disposed(by: disposeBag)
}
/// Allows the token to be set imperativly if necessary.
/// - Parameter token: The new token the service should use. It will immediatly be emitted to any subscribers to the service.
func setToken(_ token: T) {
lock.lock()
_token.onNext(token)
lock.unlock()
}
/// Monitors the source for `.unauthorized` error events and passes all other errors on. When an `.unauthorized` error is seen, `self` will get a new token and emit a signal that it's safe to retry the request.
///
/// - Parameter source: An `Observable` (or like type) that emits errors.
/// - Returns: A trigger that will emit when it's safe to retry the request.
func trackErrors<O: ObservableConvertibleType>(for source: O) -> Observable<Void> where O.Element == Error {
let lock = self.lock
let relay = self.relay
let error = source
.asObservable()
.map { error in
guard (error as? TokenAcquisitionError) == .unauthorized else { throw error }
}
.flatMap { [unowned self] in self.token }
.do(onNext: {
lock.lock()
relay.onNext($0)
lock.unlock()
})
.filter { _ in false }
.map { _ in }
return Observable.merge(token.skip(1).map { _ in }, error)
}
private let _token = ReplaySubject<T>.create(bufferSize: 1)
private let relay = PublishSubject<T>()
private let lock = NSRecursiveLock()
private let disposeBag = DisposeBag()
}
extension ObservableConvertibleType where Element == Error {
/// Monitors self for `.unauthorized` error events and passes all other errors on. When an `.unauthorized` error is seen, the `service` will get a new token and emit a signal that it's safe to retry the request.
///
/// - Parameter service: A `TokenAcquisitionService` object that is being used to store the auth token for the request.
/// - Returns: A trigger that will emit when it's safe to retry the request.
public func renewToken<T>(with service: TokenAcquisitionService<T>) -> Observable<Void> {
return service.trackErrors(for: self)
}
}
.retryWhen { $0.renewToken(with: tokenAcquisitionService) }到您的请求结束。确保您的请求发出 ResponseError.unauthorized如果 token 未经授权并且服务将处理重试。
关于swift - 如何使用 Alamofire + RxSwift 同步刷新访问 token ，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/64049955/