Authenticating users from LinkedIn or Twitter in iOS and Android using Titanium

Ti.include('lib/sha1.js');
Ti.include('lib/oauth.js');

var oauth_client = function() {

	// You will get this key and secret when you create the application in LinkedIn or twitter.
	var CONSUMER_KEY = 'xxxxxxxxxx';
	var CONSUMER_SECRET = 'xxxxxxxxxxxxxxxxxxxxxxx';

	// these are the linkedIn REST API
	var REQUEST_TOKEN_URL = 'https://api.linkedin.com/uas/oauth/requestToken';
	var AUTHORIZE_URL = 'https://api.linkedin.com/uas/oauth/authorize';
	var ACCESS_TOKEN_URL = 'https://api.linkedin.com/uas/oauth/accessToken?';
        
       // these are the twitter REST API
	/*var REQUEST_TOKEN_URL = 'https://api.twitter.com/oauth/request_token';
	var AUTHORIZE_URL = 'https://api.twitter.com/oauth/authorize';
	var ACCESS_TOKEN_URL = 'https://api.twitter.com/oauth/access_token';*/
        
       // the accessor is used when communicating with the OAuth libraries to sign the messages
	var accessor = {
		consumerSecret : CONSUMER_SECRET,
		tokenSecret : ''
	};

	var pin = null;
	var oauth_token = null;
	var oauth_token_secret = null;

	//@method get_oauth_token
	this.get_oauth_token = function() {
		return oauth_token;
	};
	
	 //@method get_oauth_token_secret
	this.get_oauth_token_secret = function() {
		return oauth_token_secret;
	};

	 //@method get_pin
	this.get_pin = function() {
		return pin;
	};

	//@method get_pin
	this.set_pin = function(html) {

		// for Twitter
		//var regExp = '(.*?)';

		// for linkedIn
		var regExp = /<div class="access-code">(.*?)<\/div>/;

		var result = RegExp(regExp).exec(html);
		if (result == null || result.length < 2) {
			pin = null;
			Ti.API.debug('Result : ' + result);
			return null;
		}
		pin = result[1];
		return pin;
	}
}

        /**
	 * 1st step of oAuth.
	 * @method request_token
	 */
	this.request_token = function(complete) {
		var message = {
			action : REQUEST_TOKEN_URL,
			method : 'POST',
			parameters : []
		};

		message.parameters.push(['oauth_consumer_key', CONSUMER_KEY]);
		message.parameters.push(['oauth_signature_method', 'HMAC-SHA1']);

		OAuth.setTimestampAndNonce(message);
		OAuth.SignatureMethod.sign(message, accessor);

		var client = Ti.Network.createHTTPClient();
		client.open('POST', REQUEST_TOKEN_URL, true);
		client.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded;');
		client.setRequestHeader("Authorization", OAuth.getAuthorizationHeader("", message.parameters));

		client.onload = function() {
			Ti.API.debug('[load]' + this.status);
			var responseParams = OAuth.getParameterMap(client.responseText);

			oauth_token = responseParams['oauth_token'];
			oauth_token_secret = responseParams['oauth_token_secret'];

			if (complete != 'undefined') {
				complete();
			}
		}
		client.send(null);
	};

       /**
	 * 2nd step of oAuth.
	 * @method get_authorize_url_with_token
	 */
        this.get_authorize_url_with_token = function() {
		return AUTHORIZE_URL + '?oauth_token=' + oauth_token;
	};

        /**
	 * 3rd step of oAuth.
	 * @method access_token
	 */
	this.access_token = function(complete) {
		accessor.tokenSecret = oauth_token_secret;

		var message = {
			action : ACCESS_TOKEN_URL,
			method : 'POST',
			parameters : []
		};
		message.parameters.push(['oauth_consumer_key', CONSUMER_KEY]);
		message.parameters.push(['oauth_token', oauth_token]);
		message.parameters.push(['oauth_signature_method', 'HMAC-SHA1']);
		message.parameters.push(['oauth_verifier', pin]);

		OAuth.setTimestampAndNonce(message);
		OAuth.SignatureMethod.sign(message, accessor);

		var client = Ti.Network.createHTTPClient();

		client.open('POST', ACCESS_TOKEN_URL, true);
		client.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded;');
		client.setRequestHeader("Authorization", OAuth.getAuthorizationHeader("", message.parameters));

		client.onload = function() {
			var responseParams = OAuth.getParameterMap(client.responseText);
			oauth_token = responseParams['oauth_token'];
			oauth_token_secret = responseParams['oauth_token_secret'];
			complete.call();
		}
		client.send(null);
	};

Ti.include('oauth_client.js');

var popup_window = Ti.UI.createWindow({
	backgroundColor : "#fff"
});

//Create the client instance.
var client = new oauth_client();

//Create the label that shows "loading" message so user knows that something is happening.
var loadingLabel = Ti.UI.createLabel({
	text : 'Loading... Please wait.',
});
popup_window.add(loadingLabel);

/**
 * This is the 2nd step of oAuth. It will show the authentication page for you to enter user name and password to authorize the app.
 */
var show_on_webview = function(url, complete) {
	var view = Ti.UI.createView({
		width : "100%",
		height : "100%",
		border : 10,
		backgroundColor : 'white',
		borderColor : '#aaa',
		borderWidth : 5,
	});
	var closeLabel = Ti.UI.createLabel({
		textAlign : 'right',
		font : {
			fontWeight : 'bold',
			fontSize : '8sp'
		},
		text : '(X)',
		top : 10,
		right : 12,
		height : 35
	});
	var webView = Ti.UI.createWebView({
		url : url,
		top : "55dp",
		width : "100%",
		height : "100%",
	});
	view.add(webView);
	webView.addEventListener('beforeload', function(e) {
		if (Ti.Platform.osname == "android")
			view.visible = false;
	});
	webView.addEventListener('load', function(e) {
		var html = e.source.html;
		client.set_pin(html);
		if ((complete != 'undefined') && (client.get_pin() != null)) {
			complete();
		}
		if (Ti.Platform.osname == "android")
			view.visible = false;
	});
	closeLabel.addEventListener('click', function() {
		popup_window.close();
	});
	view.add(closeLabel);
	popup_window.add(view);
	return;
};

/**
 * Save the token, secret and pin in file.
 */
var save_token_and_secret = function() {
	Ti.App.Properties.setString("oauth_token", client.get_oauth_token());
	Ti.App.Properties.setString("oauth_token_secret", client.get_oauth_token_secret());
	Ti.App.Properties.setString("pin", client.get_pin());
	alert("Authentication Complete");
}
/**
 * Save the token, secret and pin in file.
 */
var get_access_token = function() {
	client.access_token(function() {
		save_token_and_secret();
	});
}
var login = function() {
	client.request_token(function() {
		show_on_webview(client.get_authorize_url_with_token(), get_access_token);
	});
}
login();
popup_window.open();