Runningman: Gears, Ajax, and Comet

In the GoogleLab API, there are several awesome examples of apps you can build using Gears. For those of you that don't know what Google Gears is, heres a brief history. Google experimented with offline applications and came to a few conclusions. As they developed offline-enabled applications, they typically found the following design flaws:

• isolating the data layer
• deciding which features to implement offline (connection strategy)
• deciding on the app's modality
• implementing data synchronization

What an offline application can do is allow a user to interact with a web-service and to be productive while a connection is unavailable. Gears localizes several server features to give the user as rich of an experience as possible. Items that are localized on the client side include a data switch, server data layer, local data later, database, and a sync engine. While that may seem like a lot of stress to put on the client side, they have modules included that lighten the work load and only marginally decrease the speed of the application. When a connection is made with a server, Gears uses either Ajax or Comet to transfer data.

So back to these cool applications. The one I read into was called Runningman. Runningman is a program designed for the Android OS that allows a runner to time their run and through the use of the phones GPS, track their path on a Google Map. The group working on the mountian biking website might benefit from this example, since they are doing something very similar.

The Runningman application includes Gears and contains a full code sample that you can download and manipulate on your own. They even have a full tutorial telling you have to write the program. Way cool! As you walk through the tutorial, they show you how Gears lets you create a desktop shortcut, use Comet to update data, use the Gears Localsever to operate offline, and much more.