September 2018 Summaries

A Firebase tutorial roundup highlights community-recommended resources covering testing, security, mobile development, location services, and web applications. Featured tutorials include using Jest for test-driven Cloud Functions, building an encrypted HIPAA-compliant chat application with Firebase, improving Swift and Realtime Database integration through Codable support, triggering Firebase Cloud Functions from Radar location events, and creating a CRUD Ionic application with Cloud Firestore. The collection is aimed at developers with varied interests and experience levels, including those using iOS, Angular, and location-based app features, and invites readers to share further tutorial recommendations and Firebase projects.

Firebase Cloud Messaging (FCM) supports notification messages and data messages, which differ in priority, system handling, and app responsibilities on modern Android. Notification messages are high priority by default and are displayed by the Android system when an app is in the background, while foreground apps receive them through `onMessageReceived()` to update content or post a notification; associated data can be read from the launch intent if the user taps the notification, but not if it is dismissed. Data messages are normal priority by default and may be deferred during Doze mode, but they allow apps to decrypt payloads, customize notifications, and process content directly in `onMessageReceived()`. Because the callback has roughly 20 seconds to complete, apps should display an initial notification promptly, save or update local content, and use WorkManager or scheduled jobs for additional network work exceeding the 4 KB payload limit. Developers should also account for unordered delivery of non-collapsible messages and test FCM behavior against Android power-management features. The post recommends migrating to FCM, as C2DM was retired and Google Cloud Messaging APIs were deprecated.

Firebase has expanded Cloud Firestore’s Web SDK with experimental multi-tab offline persistence in version 5.5.0, addressing the previous limitation that allowed offline persistence in only one browser tab at a time. The feature enables multiple tabs to share persisted local data, synchronize edits while offline, and potentially reduce billing by sharing query results rather than repeatedly querying the backend. Firestore’s offline persistence already supports Android, iOS, and the web, storing data locally, executing queries from the cache, and buffering document changes until they can be sent to the backend. Multi-tab synchronization is available for Chrome, Safari, and Firefox and can be enabled through the SDK’s persistence configuration.

Firebase In-App Messaging is a Firebase feature for engaging users while they are actively using iOS or Android apps, offering a more contextual alternative to OS-level notifications that may be overlooked. Developers can create personalized, targeted messages in the Firebase Console, customize their appearance and actions, and trigger them based on user behavior, such as completing a game level or liking a first post. Campaigns can target all users, Google Analytics audiences, users with specific properties, or people predicted to perform certain behaviors, while scheduling and start/end dates support timely promotions. Developers can measure impressions, clicks, and conversion events, then edit campaigns to improve results. The tool can promote new features, sales, coupons, policy updates, subscriptions, media viewing, and purchases, with the aim of increasing app exploration, session time, and conversions.

RxFire is a JavaScript library that integrates Firebase’s realtime data services with RxJS observables, helping developers manage, transform, and combine asynchronous streams without relying on complex nested callbacks. It provides observable creation methods for Firebase Authentication, Realtime Database, Firestore, and Cloud Storage, allowing developers to apply RxJS operators such as filter, switchMap, mergeMap, and combineLatest to tasks like monitoring login state, synchronizing database lists, joining profile and cart data, and retrieving authenticated users’ storage files. Developed from lessons learned through AngularFire, RxFire is designed to work across frameworks including React, Preact, Vue, Stencil, Polymer, and plain JavaScript, while remaining a complementary layer rather than a complete Firebase wrapper. The library can also support lazy loading Firebase modules through dynamic imports and RxJS promise conversion, reducing initial application bundle sizes. Initially released in beta, RxFire is described as generally available for production use and is distributed through npm or Yarn alongside Firebase and RxJS peer dependencies.

Firebase has open sourced its first Android SDKs as part of a broader effort to increase transparency and support its developer community. The initial GitHub release includes SDKs for Cloud Firestore, Cloud Functions, Realtime Database, Storage, and FirebaseCommon, with additional SDKs planned for future release. The firebase-android-sdk repository serves as the source of truth for these components, allowing developers to follow feature and bug-fix progress, build local versions to preview upcoming releases, and access instructions for building, testing, and contributing. Developers can also report issues through GitHub, joining existing open-source Firebase SDK communities across iOS, JavaScript, Node.js, Java, Python, Go, and .NET.