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

Here are some more demos...

• 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.

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.

# 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.

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

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 signin buttons
• Setup listener for login and retrieve user info.
• Initiate the client_ids and all listeners

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 (click on dashboard)
• Google +

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

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>

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;
	});
});

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.

Initiate the environment. And add the application credentials.

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

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

Remove all sessions or individual sessions.

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

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

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

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");

Make calls to the API for getting and posting data.

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

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

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

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

hello.off("auth.login",sessionstart);

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} ).on( 'success', 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 + ". That's it!" );
		}
	}).on('error', function(){
		alert("Whoops!");
	});
}
paginationExample( "me/friends" );

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.

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.

Errors can be returned in listeners to 'error' event, i.e. hello.api([path]).on('error', [*errorhandler*]) or the 'complete' event, hello.api([path]).on('complete', [*completehandler*]) - which may also be written as hello.api([path], [*completehandler*]).

The Promise response standardizes the binding of errorHandlers.

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

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

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 + client_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 AppID/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'
	}
)

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'
});

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.

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);
});;

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

• IE7: Makes beeping sounds whenever the POST, PUT or DELETE methods are used - because of the XD, IFrame+Form+hack.-
• IE7: Requires JSON.js and localStorage shims.
• Opera Mini: Supports inline consent only, i.e. reloads original page.
• WP7: Supports inline consent only, i.e. reloads original page.

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

"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.

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

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

# run continuous integration tests
grunt test