The Current Best Hope for Cross-Platform Mobile Development

In his recent blog post Symbian on Symbian, David Wood was discussing some of the advantages of Symbian WRT Widgets. On mobile devices, widgets are essentially websites that have been bundled and loaded onto the phone.

They provide a rapid development environment using largely standardized web technologies; AJAX, HTML, CSS and Javascript. Symbian’s Web Runtime, Motorola’s WebUI, Access’ NetFront Widgets, and Windows Mobile 6.5 Widgets all use similar approaches. While iPhone, Android, and BlackBerry don’t directly support widgets, PhoneGap is an open source project that lets you build widgets for the these platforms. The spiffy new Palm Pre appears to be a widget-only environment.

This got me wondering. If all of these various widget environments really are based on standards, how close to a cross-platform solution are widgets in their current state? To find out, I conducted a quick 15 minute experiment. I downloaded the Symbian-on-Symbian WRT from Symbian.org’s developer site and dropped it into a PhoneGap Xcode project. My goal was to see how large the error count would be when I tried to compile the project. To my surprise the answer was zero! PhoneGap compiled and Xcode loaded it onto my iPhone.

Does the widget actually work in the iPhone? ….not really, there are things missing. The biggest problem appears to be that there are no softkeys on the iPhone and the Symbian WRT Javascript is expecting to find them. I could see post titles in the Symbian Forums and Symbian blog, but not the actual posts. I didn’t spend any time debugging. …as I said this was a 15 minute experiment to test a theory. It has left me with the strong suspicion that it’s possible to write some wrappers that would make Symbian and other widgets work on the platforms that PhoneGap supports. …and wrappers to move between the platforms that already support widgets may be possible as well. I’ll dig into this a bit and report back here. But certainly, the ability to reuse widget code as you move across mobile platforms offers an advantage the hard-core app development environments don’t.

PhoneGap offers an additional advantage in that the entire API library of the underlying OS is available to extend the web technologies. This, I think, argues for extending PhoneGap to those platforms that already offer a widget capability.

If you know of any wrappers for moving widgets between platforms, leave a comment and we’ll share it. You should also know that the W3C is in the early stages of formulating a set of standards for widgets that should eventually make the whole process of moving widgets across mobile platforms much easier.