Portable On Device Server
With AvantGo's Developer API release, dynamic content can also be generated on the Palm device without making a round trip to the server. AvantGo's on-device API (called PODS, Portable On Device Server, interface) allows you to create HTML dynamically through custom-shared libraries that plug into the AvantGo Client. A custom library can be built with the PODS API to support on-device business logic, field checking/validation, database lookups, and dynamic HTML creation. The PODS API supports a Document Object Model (DOM) which makes HTML pages "active" -- so that user interface components can be manipulated programmatically based on user selections, input and actions.

Interactive mobile applications
Interactive applications accept information from the user and communicate that information to enterprise server applications, corporate databases and other corporate systems. AvantGo supports HTML forms and the standard HTML user interface widgets associated with forms processing to enable interactive applications in both a network connected and disconnected environment. HTML forms are submitted to HTTP locations via the standard HTTP form Post or Get action.

Many times users will find their Palm devices are disconnected from a network. Normally, there would be an issue with trying to submit HTML forms on a computer not connected to a network. A Palm computer running the AvantGo Client need not be connected to a network to manage and process forms submissions.

In the disconnected case, the AvantGo Client will queue the submitted forms on the device and submit the forms when synchronization becomes active (connection becomes live). At that point, the server will receive all queued forms in a batch submission and the HTTP responses from the server will be transmitted and stored back on the AvantGo Client. HTTP responses take the form of normal HTML and can include all sorts of information, including order confirmations, processing status, error conditions and form transmission information.

The user can review all of the responses in the queue and delete the responses, as appropriate. In the network connected case (when your handheld device is dialed into a network or operating over TCP/IP wireless), HTML forms submissions are not queued in the Form Manager, but instead submitted to the HTTP location real-time, with the server's response displayed to the user immediately. In this case, the AvantGo Client performs similarly to a desktop Web browser in a connected environment.

When creating interactive mobile applications, it is important to keep the interface simple and not Graffiti or keyboard intensive. Forcing the user to input too much information via Graffiti or virtual keyboard interfaces is not only annoying to the user, but can lead to input errors or inaccuracies. Just as content can be generated dynamically, so can HTML forms. Form user interface (UI) widgets can be dynamically populated with predefined user choices, menus and selections. Allowing the user to just point and select will lead to a more conducive user input experience. Also, when creating applications with many form pages, be sure to group the pages in an intuitive and easily reachable order. Adhere to the "content tips" (described above) also when designing form pages.