hello.js

A client-side JavaScript SDK for authenticating with OAuth2 (and OAuth1 with a oauth proxy) web services and querying their REST APIs. HelloJS standardizes paths and responses to common APIs like Google Data Services, Facebook Graph and Windows Live Connect. It's modular, so that list is growing. No more spaghetti code!

Features

Here are some more demos...

	Windows	Facebook	Google	More..
Profile: name, picture (email)	✓	✓	✓
Friends/Contacts: name, id (email)	✓	✓	✓
Albums, name, id, web link	✓	✓	✓
Photos in albums, names, links	✓	✓	✓
Photo file: url, dimensions	✓	✓	✓
Create a new album	✓	✓
Upload a photo	✓	✓
Delete an album	✓	✗
Status updates	✗	✓	✓
Update Status	✓	✓	✗

• Items marked with a ✓ are fully working and can be tested here.
• Items marked with a ✗ aren't provided by the provider at this time.
• Blank items are a work in progress, but there is good evidence that they can be done.
• I have no knowledge of anything unlisted and would appreciate input.

Install

Download: HelloJS | HelloJS (minified)

Compiled source, which combines all of the modules, can be obtained from GitHub, and source files can be found in Source.

Bower Package

# Install the package manager, bower
npm install bower

# Install hello
bower install hello

The Bower package shall install the aforementioned "/src" and "/dist" directories. The "/src" directory provides individual modules which can be packaged as desired.

Note: Some services require OAuth1 or server-side OAuth2 authorization. In such cases, HelloJS communicates with an OAuth Proxy.

Help & Support

• GitHub for reporting bugs and feature requests.
• Gitter to reach out for help.
• Stack Overflow use tag hello.js
• Slides by Freddy Harris

Quick Start

Quick start shows you how to go from zero to loading in the name and picture of a user, like in the demo above.

• Register your app domain
• Include hello.js script
• Create the sign-in buttons
• Setup listener for login and retrieve user info
• Initiate the client_ids and all listeners

1. Register

Register your application with at least one of the following networks. Ensure you register the correct domain as they can be quite picky.

• Facebook
• Windows Live
• Google+

2. Include Hello.js script in your page

<script class="pre" src="./dist/hello.all.js"></script>

3. Create the sign-in buttons

Just add onclick events to call hello(network).login(). Style your buttons as you like; I've used zocial css, but there are many other icon sets and fonts.

<button onclick="hello('windows').login()">windows</button>

4. Add listeners for the user login

Let's define a simple function, which will load a user profile into the page after they sign in and on subsequent page refreshes. Below is our event listener which will listen for a change in the authentication event and make an API call for data.

hello.on('auth.login', function(auth) {

	// Call user information, for the given network
	hello(auth.network).api('/me').then(function(r) {
		// Inject it into the container
		var label = document.getElementById('profile_' + auth.network);
		if (!label) {
			label = document.createElement('div');
			label.id = 'profile_' + auth.network;
			document.getElementById('profile').appendChild(label);
		}
		label.innerHTML = '<img src="' + r.thumbnail + '" /> Hey ' + r.name;
	});
});

5. Configure hello.js with your client IDs and initiate all listeners

Now let's wire it up with our registration detail obtained in step 1. By passing a [key:value, ...] list into the hello.init function. e.g....

hello.init({
	facebook: FACEBOOK_CLIENT_ID,
	windows: WINDOWS_CLIENT_ID,
	google: GOOGLE_CLIENT_ID
}, {redirect_uri: 'redirect.html'});

That's it. The code above actually powers the demo at the start so, no excuses.

Core Methods

hello.init()

Initiate the environment. And add the application credentials.

hello.init({facebook: id, windows: id, google: id, ... })

name	type
credentials	object( key => value, ...  ) name type example description argument default key string windows, facebook or google App names required n/a value string 0000000AB1234 ID of the service to connect to required n/a
options	sets default options, as in hello.login()

Example:

hello.init({
	facebook: '359288236870',
	windows: '000000004403AD10'
});

hello.login()

If a network string is provided: A consent window to authenticate with that network will be initiated. Else if no network is provided a prompt to select one of the networks will open. A callback will be executed if the user authenticates and or cancels the authentication flow.

hello.login([network] [, options] [, callback()])

name	type	example	description	argument	default
network	string	windows, facebook	One of our services.	required	null
options	object name type example description argument default display string popup, page or none "popup" - as the name suggests, "page" - navigates the whole page, "none" - refresh the access_token in the background optional popup scope string email, publish or photos Comma separated list of scopes optional null redirect_uri string redirect.html A full or relative URI of a page which includes this script file hello.js optional window.location.href response_type string token, code Implicit (token) or Explicit (code) Grant flow optional token force Boolean or null true, false or null (true) initiate auth flow and prompt for reauthentication where available. (null) initiate auth flow. (false) only prompt auth flow if the scopes have changed or the token expired. optional null
callback	function	function(){alert("Logged in!");}	A callback when the users session has been initiated	optional	null

Examples:

hello('facebook').login().then(function() {
	alert('You are signed in to Facebook');
}, function(e) {
	alert('Signin error: ' + e.error.message);
});

hello.logout()

Remove all sessions or individual sessions.

hello.logout([network] [, options] [, callback()])

name	type	example	description	argument	default
network	string	windows, facebook	One of our services.	optional	null
options	object name type example description argument default force boolean true If set to true, the user will be logged out of the providers site as well as the local application. By default the user will still be signed into the providers site. optional false
callback	function	function() {alert('Logged out!');}	A callback when the users session has been terminated	optional	null

Example:

hello('facebook').logout().then(function() {
	alert('Signed out');
}, function(e) {
	alert('Signed out error: ' + e.error.message);
});

hello.getAuthResponse()

Get the current status of the session. This is a synchronous request and does not validate any session cookies which may have expired.

hello.getAuthResponse(network)

name	type	example	description	argument	default
network	string	windows, facebook	One of our services.	optional	current

Examples:

var online = function(session) {
	var currentTime = (new Date()).getTime() / 1000;
	return session && session.access_token && session.expires > currentTime;
};

var fb = hello('facebook').getAuthResponse();
var wl = hello('windows').getAuthResponse();

alert((online(fb) ? 'Signed' : 'Not signed') + ' into Facebook, ' + (online(wl) ? 'Signed' : 'Not signed') + ' into Windows Live');

hello.api()

Make calls to the API for getting and posting data.

hello.api([path], [method], [data], [callback(json)])

name	type	example	description	argument	default
path	string	/me, /me/friends	Path or URI of the resource. See REST API, Can be prefixed with the name of the service.	required	null
method	get, post, delete, put	See type	HTTP request method to use.	optional	get
data	object	{name:Hello, description:Fandelicious}	A JSON object of data, FormData, HTMLInputElement, HTMLFormElment to be sent along with a get, postor putrequest	optional	null
callback	function	function(json){console.log(json);}	A function to call with the body of the response returned in the first parameter as an object, else boolean false.	optional	null

Examples:

hello('facebook').api('me').then(function(json) {
	alert('Your name is ' + json.name);
}, function(e) {
	alert('Whoops! ' + e.error.message);
});

Event Subscription

hello.on()

Bind a callback to an event. An event may be triggered by a change in user state or a change in some detail.

hello.on(event, callback)

event	description
auth	Triggered whenever session changes
auth.login	Triggered whenever a user logs in
auth.logout	Triggered whenever a user logs out
auth.update	Triggered whenever a users credentials change

Example:

var sessionStart = function() {
	alert('Session has started');
};
hello.on('auth.login', sessionStart);

hello.off()

Remove a callback. Both event name and function must exist.

hello.off(event, callback)

hello.off('auth.login', sessionStart);

Misc

Pagination, Limit and Next Page

Responses which are a subset of the total results should provide a response.paging.next property. This can be plugged back into hello.api in order to get the next page of results.

In the example below the function paginationExample() is initially called with me/friends. Subsequent calls take the path from resp.paging.next.

function paginationExample(path) {
	hello('facebook')
		.api(path, {limit: 1})
		.then(
			function callback(resp) {
				if (resp.paging && resp.paging.next) {
					if (confirm('Got friend ' + resp.data[0].name + '. Get another?')) {
						// Call the API again but with the 'resp.paging.next` path
						paginationExample(resp.paging.next);
					}
				}
				else {
					alert('Got friend ' + resp.data[0].name);
				}
			},
			function() {
				alert('Whoops!');
			}
		);
}

paginationExample('me/friends');

Scope

The scope property defines which privileges an app requires from a network provider. The scope can be defined globally for a session through hello.init(object, {scope: 'string'}), or at the point of triggering the auth flow e.g. hello('network').login({scope: 'string'}); An app can specify multiple scopes, separated by commas - as in the example below.

hello('facebook').login({scope: 'friends,photos,publish'});

Scopes are tightly coupled with API requests, which will break if the session scope is missing or invalid. The best way to see this is next to the API paths in the hello.api reference table.

The table below illustrates some of the default scopes HelloJS exposes. Additional scopes may be added which are proprietary to a service, but be careful not to mix proprietary scopes with other services which don't know how to handle them.

Scope	Description
default	Read basic profile
friends	Read friends profiles
photos	Read users albums and photos
files	Read users files
publish	Publish status updates
publish_files	Publish photos and files

It's good practice to limit the use of scopes and also to make users aware of why your app needs certain privileges. Try to update the permissions as a user delves further into your app. For example: If the user would like to share a link with a friend, include a button that the user has to click to trigger the hello.login with the 'friends' scope, and then the handler triggers the API call after authorization.

Error Handling

Errors are returned i.e. hello.api([path]).then(null, [*errorHandler*]) - alternatively hello.api([path], [*handleSuccessOrError*]).

The Promise response standardizes the binding of error handlers.

Error Object

The first parameter of a failed request to the errorHandler may be either boolean (false) or be an Error Object...

name	type
error	object name type example description argument default code string request_token_unauthorized Code required n/a message string The provided access token.... Error message required n/a

Extending the services

Services are added to HelloJS as "modules" for more information about creating your own modules and examples, go to Modules

OAuth Proxy

A list of the service providers OAuth* mechanisms is available at Provider OAuth Mechanisms

For providers which support only OAuth1 or OAuth2 with Explicit Grant, the authentication flow needs to be signed with a secret key that may not be exposed in the browser. HelloJS gets round this problem by the use of an intermediary webservice defined by oauth_proxy. This service looks up the secret from a database and performs the handshake required to provision an access_token. In the case of OAuth1, the webservice also signs subsequent API requests.

Quick start: Register your Client ID and secret at the OAuth Proxy service, Register your App

The default proxy service is https://auth-server.herokuapp.com/. Developers may add their own network registration Client ID and secret to this service in order to get up and running. Alternatively recreate this service with node-oauth-shim. Then override the default oauth_proxy in HelloJS client script in hello.init, like so...

hello.init(
	CLIENT_IDS,
	{
		oauth_proxy: 'https://auth-server.herokuapp.com/proxy'
	}
)

Enforce Explicit Grant

Enforcing the OAuth2 Explicit Grant is done by setting response_type=code in hello.login options - or globally in hello.init options. E.g...

hello(network).login({
	response_type: 'code'
});

Refresh Access Token

Access tokens provided by services are generally short lived - typically 1 hour. Some providers allow for the token to be refreshed in the background after expiry. A list of services which enable silent authentication after the Implicit Grant signin Refresh access_token

Unlike Implicit grant; Explicit grant may return the refresh_token. HelloJS honors the OAuth2 refresh_token, and will also request a new access_token once it has expired.

Bulletproof Requests

A good way to design your app is to trigger requests through a user action, you can then test for a valid access token prior to making the API request with a potentially expired token.

var google = hello('google');
// Set force to false, to avoid triggering the OAuth flow if there is an unexpired access_token available.
google.login({force: false}).then(function() {
	google.api('me').then(handler);
});

Promises A+

The response from the async methods hello.login, hello.logout and hello.api return a thenable method which is Promise A+ compatible.

For a demo, or, if you're bundling up the library from src/* files, then please checkout Promises

Browser Support

HelloJS targets all modern browsers.

Polyfills are included in src/hello.polyfill.js this is to bring older browsers upto date. If you're using the resources located in dist/ this is already bundled in. But if you're building from source you might like to first determine whether these polyfills are required, or if you're already supporting them etc...

PhoneGap Support

HelloJS can also be run on PhoneGap applications. Checkout the demo hellojs-phonegap-demo

Contributing

"No, it's perfect!".... If you believe that then give it a star.

Having read this far you have already invested your time, why not contribute!?

HelloJS is constantly evolving, as are the services which it connects too. So if you think something could be said better, find something buggy or missing from either the code, documentation or demos then please put it in, no matter how trivial.

Changing Code?

Ensure you setup and test your code on a variety of browsers.

# Using Node.js on your dev environment
# cd into the project root and install dev dependencies
npm install -l

# Install the grunt CLI (if you haven't already)
sudo npm install -g grunt-cli

# Run the tests
grunt test