Abstracting the Backend

with NoBackend solutions.

Filip Petkovski

Every application is made up of two parts:

• The part which is unique for your app
   
• The part which is not
   
• Which one should you focus on?

Why can't we simply say:

        account.signUp({
            username: 'Filip',
            password: 'NoPassword',
            customFields: {...}
        })
        .then ( sayWelcome )
        .fail ( failGracefully );

Prototyping

In the ideal case you:

• Develop quickly
• Host cheaply
• Focus on features and user experience

Prototyping

In reality:

• You set up a database
• You choose a programming language
• You pick a framework
• You model your data
• You build a basic API
• ...
• You start building your app

So again, why don't we simply:

        products.add({
            name: 'Coke',
            description: 'Sugar in a can',
            price: '$4.99'
        })
        .then ( ... )
        .fail ( ... );

Enter NoBackend

• NoBackend is a paradigm
   
• Writing applications without focusing on the backend
   
• Your apps become feature driven
   
• You actually don't need a backend programmer

Firebase - Dashboard

Firebase - Dashboard

Firebase - Dashboard

Firebase - Modifying data

// Push data
app.child('products').push({
    name: ...,
    description: ...,
    price: ...,
    owner: ...
}, callback);

// Set data
var id = 'some-id';
app.child('products').child(id).set({
    ...
}, callback);

// Update data
app.child('products').child(id).update({...}, callback);

...
<script src="https://cdn.firebase.com/js/client/1.0.24/firebase.js"></script>
...
// Firebase root handler
var app = new Firebase("https://best-app-ever.firebaseio.com");

Firebase - Reading data

var app = new Firebase("https://best-app-ever.firebaseio.com");

// Read data once:
app.child('products').once('value', function (snapshot) {
    var data = snapshot.val();
    // process data
});

// On value changed:
app.child('products').on('value', function (snapshot) {
    var data = snapshot.val();
    // process data
});

Firebase - Reading data

// On child added:
app.child('products').on('child_added', function (snapshot) {
    var childAdded = snapshot.val();
    // ...
});

// On child removed:
app.child('products').on('child_removed', function (snapshot) {
    var removedChild = snapshot.val();
    // ...
});

Firebase - Transactions

app.child('products/5/price').transaction(function (current) {
    if (current < 10) {
        return 0;
    } else {
        return 20;
    } 
});

Firebase - Authentication

var authClient = new FirebaseSimpleLogin(app, function(error, user) {
  if (error) {
    // an error occurred while attempting login
  } else if (user) {
    // user authenticated with Firebase
  } else {
    // user is logged out
  }
});

authClient.login('password', {
  email: '<email@domain.com>',
  password: '<password>'
});

{
    "rules": {
        "products": {
            "$product_id": {
                ".read": true,
                ".write": "auth.email == data.child('owner').val()",
                ".validate": "newData.hasChildren(['name', 'price'])",
                "price": {
                    ".validate": newData.isNumber() && newData.val() > 0
                }, 
                "name": {
                    ".validate": !newData.exists()
                } 
            }
        }
    }
}

Firebase - Security

• read rules
• write rules
• validation rules

Firebase - Going offline

• Every Firebase client stores data locally
   
• Data is the synchronized with Firebase servers
   
• In the case of a conflicts, last write wins

Deployd

• Open source
   
• Self hosted
   
• NodeJS + MongoDB
   
• Module based

$ git clone https://github.com/deployd/deployd.git
$ npm install
$ npm link

Deployd - Installation

$ dpd create best-app-ever
$ cd best-app-ever
$ dpd

starting deployd v0.6.10...
deployd v0.7.0 is available.

listening on port 2403
type help for a list of commands
dpd > 

Deployd

Server side event handlers:

• Validation & Security
   
• Firing client-side events

Deployd

• MongoDB-like queries are supported
   
• Has a basic type system in place
  • string, number, boolean, object, array

Other services

Thank you!

Text

https://github.com/fpetkovski/webcampzg2014