AppDelegate.swift

//
//  AppDelegate.swift
//  EventsApp
//

import AWSAppSync
import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    var appSyncClient: AWSAppSyncClient?

    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.

        // You can choose the directory in which AppSync stores its persistent cache databases:
        //     let cacheConfiguration = AWSAppSyncCacheConfiguration(withRootDirectory: rootDirectoryURL)
        // or use the default configuration to store the databases in the app's Cache directory:
        //     let cacheConfiguration = AWSAppSyncCacheConfiguration()
        // or use in-memory (rather than persistent) caching by not specifying a cache configuration:
        //     let appSyncConfig = try AWSAppSyncClientConfiguration(appSyncServiceConfig: AWSAppSyncServiceConfig())
        // or even specify individual caches. Passing `nil` to any of these will cause it to be in-memory:
        //     let cacheConfiguration= AWSAppSyncCacheConfiguration(
        //         // or nil to use in-memory cache
        //         offlineMutations: pathToOfflineMutationDB,
        //         queries: pathToQueriesDB,
        //         subscriptionMetadataCache: pathToSubscriptionMetadataDB)

        do {
            // initialize the AppSync client configuration configuration
            let cacheConfiguration = try AWSAppSyncCacheConfiguration()
            let appSyncConfig = try AWSAppSyncClientConfiguration(appSyncServiceConfig: AWSAppSyncServiceConfig(),
                                                                  cacheConfiguration: cacheConfiguration)
            // initialize app sync client
            appSyncClient = try AWSAppSyncClient(appSyncConfig: appSyncConfig)

            // set id as the cache key for objects
            appSyncClient?.apolloClient?.cacheKeyForObject = { $0["id"] }

            print("AppSyncClient initialized with cacheConfiguration: \(cacheConfiguration)")
        } catch {
            print("Error initializing AppSync client. \(error)")
        }
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This
        // can occur for certain types of temporary interruptions (such as an incoming
        // phone call or SMS message) or when the user quits the application and it begins
        // the transition to the background state.

        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics
        // rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers,
        // and store enough application state information to restore your application to
        // its current state in case it is terminated later.

        // If your application supports background execution, this method is called
        // instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here
        // you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application
        // was inactive. If the application was previously in the background, optionally
        // refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate.
        // See also applicationDidEnterBackground:.
    }
}