初始化 appsync 客户端时出错。 invalidAuthConfiguration("AWSCognitoUserPoolsAuthProvider 不能为 nil。")答案

【问题标题】：Error initializing appsync client. invalidAuthConfiguration("AWSCognitoUserPoolsAuthProvider cannot be nil.")初始化 appsync 客户端时出错。 invalidAuthConfiguration("AWSCognitoUserPoolsAuthProvider 不能为 nil。")
【发布时间】：2020-10-05 16:32:27
【问题描述】：

我正在使用 AWS amplify 构建我的 ios 应用程序的后端。我在初始化 appsync 客户端时遇到问题。我已将 Auth 添加到后端并已登录，但我在控制台中收到以下错误：

控制台：

Error initializing appsync client. invalidAuthConfiguration("AWSCognitoUserPoolsAuthProvider cannot be nil.")

在 AppDelegate 中：

// CONFIGURE AWSAppSync
        do {
            // You can choose your database location if you wish, or use the default
            let cacheConfiguration = try AWSAppSyncCacheConfiguration()
            
            // AppSync configuration & client initialization
            let appSyncConfig = try AWSAppSyncClientConfiguration(appSyncServiceConfig: AWSAppSyncServiceConfig(), cacheConfiguration: cacheConfiguration)
            
            appSyncClient = try AWSAppSyncClient(appSyncConfig: appSyncConfig)
            print("appSyncClient initialise success \n")
        } catch {
            print("Error initializing appsync client. \(error)")
        }

我只是在这里猜测，但“appSyncConfig”变量应该是：

let appSyncConfig = try AWSAppSyncClientConfiguration(appSyncServiceConfig: AWSAppSyncServiceConfig.init(), cacheConfiguration: cacheConfiguration, userPoolsAuthProvider: AWSCognitoUserPoolsAuthProvider?)

但是我如何获得 AWSCognitoUserPoolsAuthProvider????

【问题讨论】：

标签： swift aws-amplify aws-appsync

【解决方案1】：

在配置 AWS AppSync 时，您缺少添加类以从 Cognito 用户池获取令牌的步骤。当然，这里我假设你已经选择了 Cognito User Pool 作为你的默认授权类型！

如果您对设置 amplify GraphQL 或其他任何问题有任何疑问，请告诉我！

import UIKit
import AWSAppSync
import AWSMobileClient

class MyCognitoUserPoolsAuthProvider : AWSCognitoUserPoolsAuthProviderAsync {
    func getLatestAuthToken(_ callback: @escaping (String?, Error?) -> Void) {
        AWSMobileClient.default().getTokens { (tokens, error) in
            if error != nil {
                callback(nil, error)
            } else {
                callback(tokens?.idToken?.tokenString, nil)
            }
        }
    }
}
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, UISplitViewControllerDelegate {
    var window: UIWindow?
   
    var appSyncClient: AWSAppSyncClient?
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        //// Override point for customization after application launch.
        self.initializeAppSync()
        return true
    }
    
    func initializeAppSync() {
        do {
            // You can choose the directory in which AppSync stores its persistent cache databases
            let cacheConfiguration = try AWSAppSyncCacheConfiguration()
            
            // Initialize the AWS AppSync configuration
            let appSyncConfig = try AWSAppSyncClientConfiguration(appSyncServiceConfig:
                                                                    AWSAppSyncServiceConfig(),
                                                                  userPoolsAuthProvider: MyCognitoUserPoolsAuthProvider(),
                                                                  cacheConfiguration: cacheConfiguration)
            
            // Initialize the AWS AppSync client
            appSyncClient = try AWSAppSyncClient(appSyncConfig: appSyncConfig)
            print("appSyncClient initialise success.")
        } catch {
            print("Error initializing appsync client. \(error)")
        }
    }
    
}

【讨论】：