使用Cloud Functions for Firebase和FCM提供的 Remote Config 后台功能触发,您可以实时传播 Remote Config 更新。在这种情况下,您创建一个函数,当您从仪表板或 API 发布或回滚远程配置模板时触发。模板更新触发发送 FCM 消息的函数,让客户端知道他们现有的配置已经过时,他们的下一次提取应该来自服务器:
本文档的其余部分将引导您完成这些步骤以实时传播远程配置更新。
将客户端应用程序实例订阅到 FCM 主题
为了将 FCM 消息定位到一大群客户端应用程序实例(例如您的整个用户群),主题消息传递是最有效的机制。每个应接收实时远程配置更新的应用程序实例都必须订阅主题名称,例如PUSH_RC
:
迅速
extension AppDelegate : MessagingDelegate { func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) { messaging.subscribe(toTopic: "PUSH_RC") { error in print("Subscribed to PUSH_RC topic") } } }
目标-C
- (void)messaging:(FIRMessaging *)messaging didReceiveRegistrationToken:(NSString *)fcmToken { [[FIRMessaging messaging] subscribeToTopic:@"PUSH_RC" completion:^(NSError * _Nullable error) { NSLog(@"Subscribed to PUSH_RC topic"); }]; }
安卓
@Override public void onNewToken(String s) { FirebaseMessaging.getInstance().subscribeToTopic("PUSH_RC"); }
创建一个函数以在模板更新时发送 FCM ping
您可以触发函数以响应远程配置事件,包括发布新配置版本或回滚到旧版本。要实时传播模板更新,请创建一个函数来侦听模板发布事件,然后使用函数中的 FCM Admin SDK 向客户端应用程序实例发送静默 ping:
exports.pushConfig = functions.remoteConfig.onUpdate(versionMetadata => { // Create FCM payload to send data message to PUSH_RC topic. const payload = { topic: "PUSH_RC", data: { "CONFIG_STATE": "STALE" } }; // Use the Admin SDK to send the ping via FCM. return admin.messaging().send(payload).then(resp => { console.log(resp); return null; }); });
此函数设置一个CONFIG_STATE
参数,然后将其作为 FCM 消息的数据负载发送给订阅PUSH_RC
主题的所有客户端。
在客户端设置远程配置状态
上一步中显示的数据负载始终在应用程序的共享首选项中将CONFIG_STATE
设置为STALE
。这表明已存储在应用程序中的远程配置模板现在已过时,因为创建了新的更新模板,其发布触发了该功能。更新您的通知处理程序以测试此情况:
迅速
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) { if (userInfo.index(forKey: "CONFIG_STATE") != nil) { print("Config set to stale") UserDefaults.standard.set(true, forKey:"CONFIG_STALE") } completionHandler(UIBackgroundFetchResult.newData) }
目标-C
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler { if (userInfo[@"CONFIG_STATE"]) { NSLog(@"Config set to stale"); [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"CONFIG_STALE"]; } completionHandler(UIBackgroundFetchResultNewData); }
安卓
@Override public void onMessageReceived(RemoteMessage remoteMessage) { if (remoteMessage.getData().containsKey("CONFIG_STATE")) { SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this); sharedPreferences.edit().putBoolean("CONFIG_STALE", true).apply(); } }
在应用程序启动时获取远程配置更新
迅速
func fetchConfig() { welcomeLabel.text = remoteConfig[loadingPhraseConfigKey].stringValue var expirationDuration = 3600 // If your app is using developer mode, expirationDuration is set to 0, so each fetch will // retrieve values from the service. if remoteConfig.configSettings.isDeveloperModeEnabled || UserDefaults.standard.bool(forKey: "CONFIG_STALE") { expirationDuration = 0 } remoteConfig.fetch(withExpirationDuration: TimeInterval(expirationDuration)) { (status, error) -> Void in if status == .success { print("Config fetched!") self.remoteConfig.activateFetched() } else { print("Config not fetched") print("Error: \(error?.localizedDescription ?? "No error available.")") } self.displayWelcome() } }
目标-C
- (void)fetchConfig { self.welcomeLabel.text = self.remoteConfig[kLoadingPhraseConfigKey].stringValue; long expirationDuration = 3600; // If your app is using developer mode, expirationDuration is set to 0, so each fetch will // retrieve values from the Remote Config service. if (self.remoteConfig.configSettings.isDeveloperModeEnabled || [[NSUserDefaults standardUserDefaults] boolForKey:@"CONFIG_STALE"]) { expirationDuration = 0; } [self.remoteConfig fetchWithExpirationDuration:expirationDuration completionHandler:^(FIRRemoteConfigFetchStatus status, NSError *error) { if (status == FIRRemoteConfigFetchStatusSuccess) { NSLog(@"Config fetched!"); [self.remoteConfig activateFetched]; [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"CONFIG_STALE"]; } else { NSLog(@"Config not fetched"); NSLog(@"Error %@", error.localizedDescription); } [self displayWelcome]; }]; }
安卓
private void fetchWelcomeMessage() { mWelcomeTextView.setText(mFirebaseRemoteConfig.getString("loading_phrase")); long cacheExpiration = 43200; // 12 hours in seconds. // If your app is using developer mode or cache is stale, cacheExpiration is set to 0, // so each fetch will retrieve values from the service. if (mFirebaseRemoteConfig.getInfo().getConfigSettings().isDeveloperModeEnabled() || mSharedPreferences.getBoolean("CONFIG_STALE", false)) { cacheExpiration = 0; } mFirebaseRemoteConfig.fetch(cacheExpiration) .addOnCompleteListener(this, new OnCompleteListener<Void>() { @Override public void onComplete(@NonNull Task<Void> task) { if (task.isSuccessful()) { Toast.makeText(MainActivity.this, "Fetch Succeeded", Toast.LENGTH_SHORT).show(); // After config data is successfully fetched, it must be activated before newly fetched // values are returned. mFirebaseRemoteConfig.activateFetched(); } else { Toast.makeText(MainActivity.this, "Fetch Failed", Toast.LENGTH_SHORT).show(); } mWelcomeTextView.setText(mFirebaseRemoteConfig.getString("welcome_message")); } }); }
最后,向您的应用添加逻辑以强制从网络获取远程配置(忽略本地存储),因为CONFIG_STATE
是STALE
。如果您的应用过于频繁地从网络中获取数据,它可能会受到 Firebase 的限制。请参阅节流。