Web Widgetson Android

MobileMonday Developer Day, Dusseldorf, 23 February 2010

Status Quo: Ecosystem View• Android is not YAMP! (Yet Another Mobile Platform)

• Pervasive, rich, attractive, (mostly) open• Enjoys wide industry support• Shipping 60,000 cell phones per day (but still

competing for market share)• Used increasingly in non-mobile verticals, such as

smart home• Paradigm shift for mobile Java

Status Quo: Developer View• Android is YAMP in their portfolio!• Requires new porting efforts, knowledge, testing,

devices, marketing• Avalanche of versions (1.0-2.1) in just two years!• OEMs & operators customize UI, features, APIs to

bring value and differentiate• Different features and screen sizes to be addressed

Porting for and within Android ecosystem is a full time job!

Q: What happens in 2-5 years?

Hopefully not!

Source: abcnews.go.com

Can web apps help?

Mobile Web App Ecosystem

Browser

WebServer

WebServer

WebServer

Traditional Approach to Mobile Web AppsAdvantages:• Easy, easy, easy!• Common web technologies, portable, variety of tools• Lots of web developers • Apps in the cloud easy to update

Disadvantages:• No integration with phone functions, like location, messaging,

PIM, address book, etc.• Data bandwidth• No offline mode• Web page lifecycle doesn’t feel like native app

How about web widgets?

Web Widgets (for Mobile)Define web widget:• Application, written using common web technologies (HTML,

JS, SVG, Flash, etc.)• Deployed as a single package file into the end user's browser• Processed and interpreted as a set of locally-hosted web pages• Obeying lifecycle, security and networking requirements• Lifecycle feels like a native app• Originally developed by Opera and called Opera Widgets:

http://widgets.opera.com• Evolved further into W3C Widget specification:

http://www.w3.org/TR/widgets/

Web Widget Anatomy

<?xml version="1.0" encoding="UTF-8"?>

<widget version="1.0“

xmlns="http://www.w3.org/ns/widgets"

id="http://acme.com/MyFancyWidget"

width="240"

height="320">

<name>My Fancy Widget</name>

<icon src="icons/icon.png"/>

<content src="index.html"/>

</widget>

Example: config.xml

• Packaging format: single zip file, .wgt extension• Mime type: application/widget• Configuration (manifest) file: config.xml• Entry point: index.html or custom file• Content: HTML, JS, any resource, any mime type recognized by

the browser (Flash, SVG, video, etc.)• Security and networking enforcement• Signing

Web Widget Ecosystem

WebServer

Browser

WebServic

e

xyzServer

Widget

Web Widgets (for Mobile)Advantages:• Easy, easy, easy!• Common web technologies, portable, several SDKs• Lots of web developers • Works in offline mode• Lifecycle feels like a native app

Disadvantages:• No integration with phone functions, like location, messaging,

PIM, address book, etc.

What about JIL/BONDI/WAC?

Beyond W3C Widgets• BONDI “uses web technologies and builds upon them to

provide new APIs to the key mobile phone functionality like Contacts, Calendar, Messaging & Location”

• JIL will “enable different widgets and applications to run seamlessly on different handset platforms and operating systems across different mobile operators, while safeguarding customer security, data privacy and billing systems”

• Wholesale Applications Community (WAC) “aims to unite a fragmented marketplace by involving players from all related industries to create a community based on openness and transparency to the benefit of all”

Translation please: cross-platform app model, based on W3C Widgets, extended by built-in JavaScript APIs for device access

Use Cases• Social Address Book

– Contact list from the native address book– Existing Facebook friends automatically detected– Direct access to the friend’s wall– Messaging editor with merged SMS and Facebook history– Buttons to initiate a voice/video call

• Sticky GeoNotes– Paper notes are so lame – Leave a text/voice/video message for your family and

colleagues– Based on your current location

Enriched Web Widget Ecosystem

Messaging

Location

PIM

GalleryCamera File

WebServer

Browser

WebServic

e

xyzServer

Widget

Why Should You Care?• Too many BIG players pushing for it!• JIL devices shipped in 2009• BONDI devices shipping in 2010• Cross-platform apps easier to develop!

But beware of these pitfalls:• Browser-specific workarounds• Screen sizes and orientation• Large amounts of business logic and networking code in JS may

not be too much fun

Beyond JIL/BONDI/WAC(Problem solved! What else can we ask for?)

Beyond JIL/BONDI/WAC

Wouldn’t you like to:… expose your own services to widgets?… write business logic in Java rather than JavaScript?… write networking code in Java rather than JavaScript?… leave the widget code to UI designers and developers?

You’d be out of luck nowadays: current implementations don’t provide means to extend the device APIs

Mobile OSGi

But there are efforts in that direction based on mobile OSGi:• OSGi used on mobile, embedded, smart home, enterprise

platforms, and spreading• Mobile OSGi (JSR 232) deployed on a wide variety of mobile

platforms (Android, Symbian, WM, BREW)• Enables dynamic code deployment and update, dynamic

service wiring, code reuse, versioning and more:http://www.osgi.org/About/WhyOSGi

• OSGi complements, not replaces Android platformhttp://www.osgi.org/About/Technology

Mobile OSGi + Web Widgets

Messaging

Location

PIM

GalleryCamera File

WebServer

WebServer

App

ServiceMobile OSGi

Browser

WebServic

e

xyzServer

Widget

Remote OSGi Services

Mobile OSGi and Web Widgets? So, how does it work:

Step 1: Design and implement your service in Java

public interface MyService {

public void doSomething(String param);

}

Step 2: Register in OSGi as “remotable” service

MyService instance = new MyServiceImpl();

Properties props = new Properties();

props.put("org.osgi.remote.publish", Boolean.TRUE);

bundleContext.registerService(MyService.class.getName(),

instance, props);

Using Services from Widgets

Step 3: Use Remote Service Registry JS API to bind services and get a proxy service object

var so = RSR.bind(“MyService”);

Step 4: Invoke a function on the proxy service object

so.doSomething(“param”);

Easy enough!

Conclusion

Web Widgets increasingly seen as a cross-platform app model with huge market potential

Android-based devices supporting Web Widgets are shipping now

Web Widgets are empowered with rich device access capabilities

Mobile OSGi offers a middleware solution to allow dynamic APIs for Widgets

Additional resources:www.prosyst.com

dz.prosyst.commobileosgi.blogspot.com

Thanks Sinisha Djukics.djukic@prosyst.com