ios - AWS iOS SDK Cognito 开发人员身份验证 (Swift)

Question

我很难弄清楚如何将我的服务器(通过 AWS)提供的开发人员凭据返回给我的示例身份提供商。

看来我需要在 ExampleIdentityProvider 类的 refresh 方法中同步执行此操作。我正在使用 AFNetworking 发出请求，但它是一个异步 GET 请求。如何为我的 IdentityProvider 上的刷新方法同步执行此操作？

以下是 Swift 中的内容:

class ExampleIdentityProvider: AWSAbstractIdentityProvider  {
    var newToken: String!

    override var token: String {
        get {
            return newToken
        }
        set {
            newToken = newValue
        }
    }

    override func getIdentityId() -> BFTask! {
        if self.identityId != nil {
            return BFTask(result: self.identityId)
        }else{
            return BFTask(result: nil).continueWithBlock({ (task) -> AnyObject! in
                if self.identityId == nil {
                    return self.refresh()
                }
                return BFTask(result: self.identityId)
            })
        }
    }

    override func refresh() -> BFTask! {
        return BFTask(result: nil).continueWithBlock({ (task) -> AnyObject! in
            let result =  AFNETWORKING REQUEST FOR CREDENTIALS TO MY SERVER
            self.identityId = result.identityId
            self.token = result.token

            return BFTask(result: self.identityId)
        })
    }
}

Answer 1

我相信我已经弄明白了。我需要利用 BFTask，它是为处理后台任务而构建的。

对于使用 Cognito 快速实现开发人员身份验证的人来说，他们可能与我有类似的设置，这就是我完成它的方式:

class ExampleAppIdentityProvider: AWSAbstractCognitoIdentityProvider {
    var _token: String!
    var _logins: [ NSObject : AnyObject ]!

    // Header stuff you may not need but I use for auth with my server
    let acceptHeader = "application/vnd.exampleapp-api+json;version=1;"
    let authHeader = "Token token="
    let userDefaults = NSUserDefaults.standardUserDefaults()
    let authToken = self.userDefaults.valueForKey("authentication_token") as String

    // End point that my server gives amazon identityId and tokens to authorized users
    let url = "https://api.myapp.com/api/amazon_id/"

    override var token: String {
        get {
            return _token
        }
    }

    override var logins: [ NSObject : AnyObject ]! {
        get {
            return _logins
        }
        set {
            _logins = newValue
        }
    }

    override func getIdentityId() -> BFTask! {
        if self.identityId != nil {
            return BFTask(result: self.identityId)
        }else{
            return BFTask(result: nil).continueWithBlock({ (task) -> AnyObject! in
                if self.identityId == nil {
                    return self.refresh()
                }
                return BFTask(result: self.identityId)
            })
        }
    }

    override func refresh() -> BFTask! {
        let task = BFTaskCompletionSource()
        let request = AFHTTPRequestOperationManager()
        request.requestSerializer.setValue(self.acceptHeader, forHTTPHeaderField: "ACCEPT")
        request.requestSerializer.setValue(self.authHeader+authToken, forHTTPHeaderField: "AUTHORIZATION")
        request.GET(self.url, parameters: nil, success: { (request: AFHTTPRequestOperation!, response: AnyObject!) -> Void in
            // The following 3 lines are required as referenced here: http://stackoverflow.com/a/26741208/535363
            var tmp = NSMutableDictionary()
            tmp.setObject("temp", forKey: "ExampleApp")
            self.logins = tmp

            // Get the properties from my server response
            let properties: NSDictionary = response.objectForKey("properties") as NSDictionary
            let amazonId = properties.objectForKey("amazon_identity") as String
            let amazonToken = properties.objectForKey("token") as String

            // Set the identityId and token for the ExampleAppIdentityProvider
            self.identityId = amazonId
            self._token = amazonToken

            task.setResult(response)
        }, failure: { (request: AFHTTPRequestOperation!, error: NSError!) -> Void in
            task.setError(error)
        })
        return task.task
    }
}

并通过以下操作初始化 ExampleAppIdentityProvider:

    let identityProvider = ExampleAppIdentityProvider()
    let credentialsProvider = AWSCognitoCredentialsProvider(regionType: AWSRegionType.USEast1, identityProvider: identityProvider, unauthRoleArn: GlobalVariables.cognitoUnauthRoleArn, authRoleArn: GlobalVariables.cognitoAuthRoleArn)
    let defaultServiceConfiguration = AWSServiceConfiguration(region: .USEast1, credentialsProvider: credentialsProvider)
    AWSServiceManager.defaultServiceManager().defaultServiceConfiguration = defaultServiceConfiguration

    let transferManager = AWSS3TransferManager.defaultS3TransferManager()

    let uploadRequest = AWSS3TransferManagerUploadRequest()
    uploadRequest.bucket = GlobalVariables.awsBucket
    uploadRequest.key = "\(GlobalVariables.environment)/uploads/users/\(userId)/\(type)/\(timestamp)/original.jpg"
    uploadRequest.ACL = .AuthenticatedRead
    uploadRequest.body = tmpFileUrl

    // Upload file
    let task = transferManager.upload(uploadRequest)

我创建了一个名为 GlobalVariables 的 struct，其中包含保存 bucket、unAuthRoleArn、authRoleArn 等。当然你不必这样做，但我提到它以防有人感到困惑。