app.js

var token = 'T1==cGFydG5lcl9pZD00NTkzMTM4MiZzaWc9NGY4NDQyMzc5ZDNiZTczNmFiYWI3OTljMmUxZjQxNjEzYWFmYjlmNTpzZXNzaW9uX2lkPTFfTVg0ME5Ua3pNVE00TW41LU1UVXdNVGd5TXpnd01USXpNbjVTYXpWYUwwMHZkRUpGVmpsRU5sYzJlRXhKTUd0R2FrOS1VSDQmY3JlYXRlX3RpbWU9MTUwMTgyMzgwMSZyb2xlPXB1Ymxpc2hlciZub25jZT0xNTAxODIzODAxLjMzMDIxODY1NDYzODE2';
var session_key = '1_MX40NTkzMTM4Mn5-MTUwMTgyMzgwMTIzMn5SazVaL00vdEJFVjlENlc2eExJMGtGak9-UH4';
var api_key = '45931382';

// var pubOptions = {publishAudio:true, publishVideo:false};

// connect to open tok api using client side library
var session = OT.initSession(api_key, session_key);


// when other user is connected we want to show them
// in subscriber div element
session.on('streamCreated', function (event) {
    session.subscribe(event.stream, 'subscriber', {
        insertMode: 'append',
        width: '100%',
        height: '100%'
    });
});

// when first user loads this page we want him to
// be shown in publisher div element
var publisher = OT.initPublisher('publisher', {
    insertMode: 'append',
    width: '100%',
    height: '100%'
});

// if we have any connection error let's put an alert box
session.connect(token, function (error) {
    var publisher = OT.initPublisher('camera');
    session.publish(publisher, function () {
        screenshare();
    });
    if (error) {
        alert(error.message);
    } else {
        session.publish(publisher);
    }
});

OT.registerScreenSharingExtension('chrome', extensionId, 2);

function screenshare() {
    OT.checkScreenSharingCapability(function (response) {
        if (!response.supported || response.extensionRegistered === false) {
            alert('This browser does not support screen sharing.');
        } else if (response.extensionInstalled === false) {
            alert('Please install the screen sharing extension and load your app over https.');
        } else {
            // Screen sharing is available. Publish the screen.
            var screenSharingPublisher = OT.initPublisher('screen-preview', {videoSource: 'screen'});
            session.publish(screenSharingPublisher, function (error) {
                if (error) {
                    alert('Could not share the screen: ' + error.message);
                }
            });
        }
    });
}