1. 环境

项目使用 MVVM 架构，引入了 Rx 全家桶，网络请求框架使用了 Moya，以及处理 Oauth 相关的库 OAuth3。

2. OAuth3 部分

参阅 OAuth3 库的 README，完成 OAuth 的信息配置：

let oauth3 = OAuth3CodeGrant(settings: [  "client_id": "my_swift_app",  "client_secret": "C7447242",  "authorize_uri": "https://github.com/login/oauth/authorize",  "token_uri": "https://github.com/login/oauth/access_token",  "redirect_uris": ["myapp://oauth/callback"],  "scope": "user repo:status",  "secret_in_body": true,  "keychain": false,] as OAuth3JSON)

同时因为 Moya 的底层网络请求实现是基于 Alamofire，因此我们可以参照 OAuth3 提供的说明文档 Alamofire 4 · p2/OAuth3 Wiki · GitHub完成相关配置，关键代码如下：

import Foundationimport OAuth3import Alamofireclass OAuth3RetryHandler: RequestRetrier, RequestAdapter {  let loader: OAuth3DataLoader  init(oauth3: OAuth3) {    loader = OAuth3DataLoader(oauth3: oauth3)  }  /// Intercept 401 and do an OAuth3 authorization.  public func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion) {    if let response = request.task?.response as? HTTPURLResponse, 401 == response.statusCode, let req = request.request {      var dataRequest = OAuth3DataRequest(request: req, callback: { _ in })      dataRequest.context = completion      loader.enqueue(request: dataRequest)      loader.attemptToAuthorize() { authParams, error in        self.loader.dequeueAndApply() { req in          if let comp = req.context as? RequestRetryCompletion {            comp(nil != authParams, 0.0)          }        }      }    }    else {      completion(false, 0.0)  // not a 401, not our problem    }  }  /// Sign the request with the access token.  public func adapt(_ urlRequest: URLRequest) throws -> URLRequest {    guard nil != loader.oauth3.accessToken else {      return urlRequest    }    return try urlRequest.signed(with: loader.oauth3)  // "try" added in 3.0.2  }}

3. Moya 部分

Moya 的 provider 在初始化时可以传入 SessionManager ，因此参照文档，可以先使用 OAuth3 生成一个特定的 SessionManager ：

func getManager() -> SessionManager {    let oauth3 = OAuth3CodeGrant(settings: [      "client_id": "my_swift_app",      "client_secret": "C7447242",      "authorize_uri": "https://github.com/login/oauth/authorize",      "token_uri": "https://github.com/login/oauth/access_token",      "redirect_uris": ["myapp://oauth/callback"],      "scope": "user repo:status",      "secret_in_body": true,      "keychain": false,      ] as OAuth3JSON)    let sessionManager = SessionManager()    let oauthHandler = OAuth3Handler(oauth3: oauth3)    sessionManager.adapter = oauthHandler    sessionManager.retrier = oauthHandler    return sessionManager  }

进而生成带 OAuth 的 provider：

fileprivate lazy var provider: MoyaProvider = {  return MoyaProvider(manager: self.getManager(),              plugins: [NetworkLoggerPlugin()])}()