Web Widgets
on 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?
Source: abcnews.go.com
Hopefully not!
Can web apps help?
Mobile Web App Ecosystem
Browser
Web
Web Server
Server
Web
Server
Traditional Approach to Mobile Web Apps
Advantages:
• 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
• 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
Browser
Widget xyz
Web Server
Server
Web
Service
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
Browser
Widget xyz
Web Server
Server
Web
Service
Camera Gallery File
Location PIM Messaging
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 platform
http://www.osgi.org/About/Technology
Mobile OSGi + Web Widgets
Browser
Widget xyz
Web Server
Server
Web
Service
App Web
Server
Service
Mobile OSGi
Camera Gallery File
Location PIM Messaging
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
Thanks Sinisha Djukic
s.djukic@prosyst.com
Additional resources:
www.prosyst.com
dz.prosyst.com
mobileosgi.blogspot.com