AlamoFireの提供するOAuthの実装例を得ることができました。しかし、私は特定のコード行とそれがどのように動作するのかを理解しようとしています。AlamoFireの理解OAuthの例
全例:
class OAuth2Handler: RequestAdapter, RequestRetrier {
private typealias RefreshCompletion = (_ succeeded: Bool, _ accessToken: String?, _ refreshToken: String?) -> Void
private let sessionManager: SessionManager = {
let configuration = URLSessionConfiguration.default
configuration.httpAdditionalHeaders = SessionManager.defaultHTTPHeaders
return SessionManager(configuration: configuration)
}()
private let lock = NSLock()
private var clientID: String
private var baseURLString: String
private var accessToken: String
private var refreshToken: String
private var isRefreshing = false
private var requestsToRetry: [RequestRetryCompletion] = []
// MARK: - Initialization
public init(clientID: String, baseURLString: String, accessToken: String, refreshToken: String) {
self.clientID = clientID
self.baseURLString = baseURLString
self.accessToken = accessToken
self.refreshToken = refreshToken
}
// MARK: - RequestAdapter
func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
if let urlString = urlRequest.url?.absoluteString, urlString.hasPrefix(baseURLString) {
var urlRequest = urlRequest
urlRequest.setValue("Bearer " + accessToken, forHTTPHeaderField: "Authorization")
return urlRequest
}
return urlRequest
}
// MARK: - RequestRetrier
func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion) {
lock.lock() ; defer { lock.unlock() }
if let response = request.task?.response as? HTTPURLResponse, response.statusCode == 401 {
requestsToRetry.append(completion)
if !isRefreshing {
refreshTokens { [weak self] succeeded, accessToken, refreshToken in
guard let strongSelf = self else { return }
strongSelf.lock.lock() ; defer { strongSelf.lock.unlock() }
if let accessToken = accessToken, let refreshToken = refreshToken {
strongSelf.accessToken = accessToken
strongSelf.refreshToken = refreshToken
}
strongSelf.requestsToRetry.forEach { $0(succeeded, 0.0) }
strongSelf.requestsToRetry.removeAll()
}
}
} else {
completion(false, 0.0)
}
}
// MARK: - Private - Refresh Tokens
private func refreshTokens(completion: @escaping RefreshCompletion) {
guard !isRefreshing else { return }
isRefreshing = true
let urlString = "\(baseURLString)/oauth2/token"
let parameters: [String: Any] = [
"access_token": accessToken,
"refresh_token": refreshToken,
"client_id": clientID,
"grant_type": "refresh_token"
]
sessionManager.request(urlString, method: .post, parameters: parameters, encoding: JSONEncoding.default)
.responseJSON { [weak self] response in
guard let strongSelf = self else { return }
if
let json = response.result.value as? [String: Any],
let accessToken = json["access_token"] as? String,
let refreshToken = json["refresh_token"] as? String
{
completion(true, accessToken, refreshToken)
} else {
completion(false, nil, nil)
}
strongSelf.isRefreshing = false
}
}
}
質問:
[weak self] succeeded, accessToken, refreshToken in
guard let strongSelf = self else { return }
[weak self]
とstrongSelf
ためguard
の目的は何ですか?requestsToRetry.append(completion) if !isRefreshing { refreshTokens { [weak self] succeeded, accessToken, refreshToken in guard let strongSelf = self else { return } //Implementation strongSelf.requestsToRetry.forEach { $0(succeeded, 0.0) } strongSelf.requestsToRetry.removeAll() } }
この要求はどのように再試行されますか?
requestsToRetry
はただの配列ですRequestRetryCompletion = (_ shouldRetry: Bool, _ timeDelay: TimeInterval)
どのような要求を再試行するかはどのように分かりますか?
strongSelf.lock.lock()
NSLock
はちょうどこの方法の実行中self
(OAuth2Handler)が他のスレッドによってアクセスされることを可能にしませんか?
1は 'self'への強い参照を得て、次のコードでは' self'を使用しようとしません。なぜなら、そのコンテキストで 'self'が弱いため、強い参照が最後に解放されるからです保持サイクルは発生しません。 alamofireに精通していないので、残りの部分は確かに言う。 – Fonix