Sunday, September 6, 2015

Firebase as your app's backend


Firebase is a cloud based back-end as a service provider. It can be used as a very effective No SQL data-store. Your application can store JSON objects. Integration is made easy with variety of libraries provided by Firebase. For this blog I'm focusing on Web/JavaScript library.

As a developer it's quick to get started. No overhead of installation and setup. It's a cloud service, so don't have worry about setting-up servers. Firebase tools on your machine are provided as an NPM package. Install with following command, globally on your machine.

npm install firebase-tools -g

This makes it a good choice for independent mobile/web app developers. Signup and login to Firebase.
Create an app. Remeber your app has a URL. JSON Key/Value pairs are shown at that URL. You might chose to manually add/remove/modify data as well.

Synchronized:

As and when data is updated in the backend, JavaScript events are raised and the callbacks provided are invoked with updated data. Hence your app is in near synchronous state all the time. With this approach we write less code, retrieving data is made simpler. Down below I've mentioned couple of data retrieval options. Checkout more here.

Consider Two Tier Architecture

With JavaScript and browsers being more and more powerful, you don't have to look at mandatory middle tier. Firebase can act as your middle tier and data store. Security, validation and authentication features of Firebase do allow this kind of architecture. 

Get Started

by referencing Firebase library in your Web Page. You could use CDN location. Or by downloading Firebase bower or npm package. I chose bower (package manager).

bower install firebase

And reference of firebase.js in bower_components. There after

//create an object of Firebase
var ref = new Firebase('URL of your firebase app');

Save Data to Firebase:

// to set a primitive data value
ref.set('sample value')
ref.set(100);

// you may set a JSON object instead
ref.set({
field1: 1,
field2: {
  child1: 'value'
}});

//If you are storing a new object every time, use push (array) instead of set.
ref.push({
field1: 1,
field2: {
  child1: 'value'
}});

Retrieve data from Firebase:

As mentioned earlier, Firebase keeps data synchronized. Data is pushed to the browser as changes happen. JavaScript code need to have callback functions defined to update view as data is retrieved automatically.

//Look for changes to the data
ref.on('value', function(snapshot){
    console.log(snapshot.val());
});

// data added as a child node.
ref.on('child_added', function(snapshot){
    console.log(snapshot.val());
})


All data elements in Firebase are represented by URL. You can traverse through the nodes in the URL itself. For example, to reach child1 in above example, you could provide URL "http://yourapp.firebase.io/field2/child1" to the Firebase function.

or you could use ref.child('field1/child1')


Running your application:

You may use any Web-Server to serve HTML files on your machine. Serve is a good choice.

npm install serve -g

Run serve from at the root folder of your application.
Firebase also provides hosting service. Run

firebase init
(Link application to Firebase app in this step.)

firebase deploy
(Deploys to Firebase cloud service)

You can serve HTML files on the cloud now. URL is on App Card It will be your appname.firebasepp.com

This is an introductory blog. Do checkout Security, Authentication, OAuth and Offline features of Firebase.


Also, I've basic Firebase examples on my Github. Use this link to explore.