If you're like me, you're really excited about React Native, a new way to build (native!) mobile applications with JavaScript. Today, I'm happy to announce that thanks to the efforts of our developer community, Firebase and React Native now work together.

Hold up, what is React?

React is a view library created and maintained by Facebook. I love React for its declarative API, which makes managing changes in your views dead simple.

When you build your application's views with React, it automatically updates the UI of your application when it observes state changes in your data model. Conveniently, Firebase databases deliver a stream of realtime updates to your data model. With Firebase and React, it's effortless to create components that automatically update in realtime. The two pair beautifully together.

If you're not familiar with React — and for more details on using it with Firebase — our very own Jacob Wenger wrote this excellent introduction to Firebase and React, which explains the basics of React in more detail.

What is React Native?

React Native is a new framework that helps you build applications for native platforms primarily with JavaScript and React. React Native for iOS was released earlier this year. The React Native components in your iOS app render directly to real, native UIKit components — it's not a web app running on a mobile device.

Here's an example of some JavaScript you might write to create a simple view, from the React Native homepage. If you're familiar with React, you'll notice how instead of declaring HTML DOM elements like <div>s and <p>s, you declare components that map directly to standard iOS platform components.

    var React = require('react-native');
    var { TabBarIOS, NavigatorIOS } = React;

    var App = React.createClass({
      render: function() {
        return (
          <TabBarIOS>
            <TabBarIOS.Item title="React Native" selected={true}>
              <NavigatorIOS initialRoute={{ title: 'React Native' }} />
            </TabBarIOS.Item>
          </TabBarIOS>
        );
      },
    });

Did I mention this is just JavaScript? React Native also has support for ES6 syntax (shown above), and you can write your app with Flow, Facebook's static type checker for JavaScript.

Other bonuses of React Native include support for npm modules, debugging in Chrome Developer Tools, and instant reload in XCode (as in, hit Cmd-R and your app reloads in a few seconds instead of having to do full XCode rebuilds). It's a wonderful development experience.

Although React Native is still in beta, it's currently being used in production in some of Facebook's apps, including its Groups app.

In short, I'm excited about React Native because it lets me write native mobile apps with the technologies I use every day as a web developer.

Sounds great! How do I get started?

If you'd like to start getting your hands dirty with React Native, the official tutorial is an excellent place to start.

Once you've created your React Native app, just head to your nearest terminal and enter these magic characters to install Firebase via npm:

    npm install firebase --save

Then, in your JavaScript code just softly whisper var Firebase = require('firebase'); and all the power of the Firebase JavaScript SDK and React Native will be yours!

If you have any questions, bug reports, general commentary, or if you just want to say hi, you can find me on Twitter at @KanYang.

A special shoutout

Thanks to Harrison Harnisch, a developer in our community, for helping to get support for WebSockets merged into React Native!

Have you ever had an app suddenly stop working when you lost your internet connection? Or perhaps you've opened an app you were using just minutes prior, only to find you have to re-download all of your data?

As a developer, you've likely tried to solve these pain points in your own apps, only to find the work required to be daunting. Wouldn't it be great if your database could just handle this for you automatically?

Firebase Offline to the Rescue

Today we're announcing a set of features for our iOS and Android SDKs that will allow you to build apps that work smoothly offline!

Our new SDKs support persisting your synchronized data to disk, so it's available immediately when your app starts. You can enable disk persistence with one line of code:

Firebase.getDefaultConfig().setPersistenceEnabled(true);

[Firebase defaultConfig].persistenceEnabled = YES;

Firebase.defaultConfig().persistenceEnabled = true

Our new SDKs now also let you specify data to be prefetched and kept up to date so that it will be available offline later if you need it. This keepSynced feature can be enabled on a per-path basis with one line of code:

ref.keepSynced(true);

[ref keepSynced:YES];

ref.keepSynced(true)

Built from the Beginning for Offline

The Firebase database uses synchronization rather than request / response to move data between client and server. All read and write operations happen against a local, on-device version of your database first. Then, data is pushed and pulled from our servers behind the scenes. This design has allowed the Firebase database to compensate for network latency -- local write operations are reflected by local reads before being acknowledged by the server.

It turns out, though, that this design is also essential to a high quality offline experience. By sending all reads and writes through a local version of the database, the Firebase SDK maintains the freedom to serve that data from the best source available -- whether that’s from the network or local disk. Later, when a network connection becomes available, our SDK automatically commits local operations to the server and pulls in the latest remote updates.

We designed Firebase for offline support from the very beginning, and we've been working on it for years. Citrix has been beta testing our offline support for its iOS app Talkboard since 2013. When you draw on a canvas in Talkboard, any updates you make while offline will be saved to disk and synchronized later when you reopen the app.

Getting Started

We've been working on these features for a long time, and we couldn't be more excited to see what you build with them! Getting started is easy -- just check out the offline section of our guides for iOS or Android. We also have offline drawing examples for iOS and Android that can help you get started quickly.

As you're coding, we'd love to hear what you think! Please share your feedback in our Google Group or mention @Firebase on Twitter.

Many of our developers are using Firebase with a server to perform tasks like background processing, integrating with third party APIs, or handling advanced authentication requirements. Today, we're introducing Firebase Queue, a fault-tolerant multi-worker job pipeline built on Firebase.

If you're writing your server code in Node, Firebase Queue makes it easy to handle background jobs with a worker queue. We're already using it in our private backups feature, where we reliably handle hundreds of jobs per day across multiple machines.

Creating a Queue

Once you've installed firebase and firebase-queue, you can get started by creating a new Queue and passing it your Firebase reference and a processing function. This processing function specifies the data transformation that the worker performs and when called, will be passed the following four parameters:

• data - A plain JavaScript object containing the claimed task’s data
• progress() - A callback function that takes a number from 0 to 100 to report the progress state of the item
• resolve() - A callback function that marks the task as complete and allows the worker to process another task
• reject() - A callback function that reports any errors from processing the job and allows the worker to move on to processing new tasks

Below is a simple example of what an instance of the queue looks like:

var Queue = require('firebase-queue'),
    Firebase = require('firebase');

var queueRef = new Firebase('https://<YOUR-FIREBASE-APP>.firebaseio.com/queue');
var queue = new Queue(queueRef, function(data, progress, resolve, reject) {
  // Read and process task data
  console.log(data);

  // Update the progress state of the task
  setTimeout(function() {
    progress(50);
  }, 500);

  // Finish the job asynchronously
  setTimeout(function() {
    resolve();
  }, 1000);
});

When your Queue runs, the data will be stored in Firebase under a /queue/tasks path and removed when complete. For an item in your queue called example1, the data in Firebase would look like the following:

{
  "queue": {
    "tasks": {
      "example1": {
        "_owner": "worker_1", // The worker process who owns this task
        "_progress": 88, // A number from 0 to 100 indicating the item’s status in the queue
        "_state": "in_progress", // Indicates whether the job has errored, is in progress or finished
        "_state_changed": 1430937731946, // Timestamp when the state was last updated
        "your": "data" // Original data in your task
      }
    }
  }
}

Adding Tasks to the Queue

You can push an object with some data to the /queue/tasks location in your Firebase using any Firebase client or the REST API. Workers listening at that location will automatically pick up and process the job:

Firebase ref = new Firebase("https://<YOUR-FIREBASE-APP>.firebaseio.com/queue/tasks");
Map task = new HashMap();
task.put("your", "data");
ref.push().setValue(task);

Firebase *ref = [[Firebase alloc] initWithUrl:@"https://<YOUR-FIREBASE-APP>.firebaseio.com/queue/tasks"];
[[ref childByAutoId] setValue:@{@"your": @"data"}];

var ref = Firebase(url: "https://<YOUR-FIREBASE-APP>.firebaseio.com/queue/tasks")
ref.childByAutoId().setValue(["your": "data"])

var ref = new Firebase("https://<YOUR-FIREBASE-APP>.firebaseio.com/queue/tasks");
ref.push({"your": "data"});

curl -X POST -d '{"your": "data"}' https://<YOUR-FIREBASE-APP>.firebaseio.com/queue/tasks.json"

If you don't want to use the default spec, you can define your own. You can also chain several specs together to create custom jobs. More details on customizing and chaining jobs can be found in the Firebase Queue README.

Queue Examples

We have a few examples to help you get started with Firebase Queue. This gist creates a new Queue with 10 workers and a custom task task_1. In this example, the queue sanitizes chat messages to make sure they don’t contain any banned words.

I'd like your feedback!

When you try out firebase-queue in your app I'd like to hear what you think. Send a pull request, file an issue, or reach out to me on Twitter @drTriumph.

Ionic is an HTML5 mobile app SDK that makes it extremely simple to build native-feeling iOS and Android apps with JavaScript. It’s built on top of Cordova and uses AngularJS for its core functionality. I love learning new frameworks, and I’ve been thoroughly impressed with how easy it is to get up and running with Ionic. Since Ionic uses Angular, it’s incredibly simple to wire up with Firebase as the backend.

This screencast will help you dive into mobile web development with Ionic in less than 8 minutes. It assumes you are familiar with the basics of Angular and walks you through building a cross-platform collaborative grocery list application. Check it out below: