An Add-On Strikes a Happy Medium

AppForge's VB tool mobilizes apps minus C++

AppForge Inc.s namesake add-on for Visual Basic is a great way for companies to leverage their training and software investment in Microsoft Corp.s Visual Basic programming language to speed development of applications for Palm OS-based handhelds.

Forms-based development applications for the Palm OS platform such as Pendragon Software Corp.s Pendragon Forms and Pumatech Inc.s Satellite Forms offer companies a simpler route to basic mobile application development. Whats more, Pendragon and Pumatech offer out-of-the-box synchronization server options that AppForge lacks.

But AppForge and Visual Basic enable companies to develop more-complex mobile applications, with a significantly less-steep learning curve than lower-level, C++-based programming tools such as Metrowerks Corp.s CodeWarrior.

eWeek Labs tested AppForge Professional Edition 1.1, which began shipping in February and is priced at $695. AppForge also sells a $199 Standard Edition, which contains fewer Visual Basic controls and lacks the Palm OS extensibility and ODBC (Open Database Connectivity) database synchronization features of the Professional Edition.

AppForge software requires Microsoft?s Visual Basic 6.0, with Service Pack 4 installed. Visual Basic 6.0 Professional sells for $550, bringing the total cost to develop with AppForge to $1,245. Although this cost is significantly higher than the $795 Satellite Forms 4.0 Enterprise Edition or the $149 Pendragon Forms 3.1, AppForge is intended primarily for Visual Basic programmers, who are likely already to have Visual Basic 6.0.

To run on Palm OS devices, AppForge programs require a 300KB run-time module called AppForge Booster, which is freely distributable. This means that applications developed with AppForges software may be distributed to an unlimited number of users. Satellite Forms follows a similar licensing model. Programs developed with Pendragon Forms carry a per-user license fee of $30 for 100 or more users, which offsets its lower initial price.

AppForge applications run on devices running Palm OS 3.1 or later. AppForge applications do not support color.

Companies that wish to develop Visual Basic applications for Pocket PC devices may do so with Microsoft?s Embedded Visual Tools 3.0, available for free from Microsofts Web site.

AppForging ahead

When the appforge add-on is installed, an AppForge project template appears in Visual Basic 6.0, complete with 17 AppForge-specific Visual Basic controls, called ingots. AppForge ingots are designed to operate in the resource-strapped Palm OS environment, approximating the functionality of Visual Basics standard ActiveX components. AppForge does not support standard Visual Basic controls, and it offers no way to directly convert Visual Basic applications to run on Palm OS devices.

The AppForge ingots appear in the interface alongside the standard Visual Basic controls and are distinguished from those controls by a yellow "i" on each button. Wed like to see the standard controls removed from the tool bar to cut down on clutter.

In tests, we were able to create applications using the AppForge ingots in the same way as the standard Visual Basic controls, and we could compile the applications to run on Windows machines in addition to Palm OS devices. This allows developers to test their AppForge programs on their development machines before transferring them to target Palm OS devices.

AppForge ships with a utility that converts Microsoft Access 97 or 2000 databases into PDB (Palm Database) files, which are then used to store AppForge program data on target devices. Unique to the Professional Edition of AppForge is the AppForge Universal Conduit, which allows for synchronization of data stored in PDB files with Access or another ODBC-compliant database on a desktop computer. AppForge?s Universal Conduit works with Palm Inc.s HotSync application and appears in the HotSync interface among other installed conduits, such as those for mail and contact-list synchronization.

Also unique to the Professional version of AppForge is the Palm OS Extensibility Library, which gives developers access to other applications on a Palm OS device. In this way, AppForge programs can access data stored in native Palm applications such as contacts or date book entries. To use the Palm OS Extensibility Library, developers must write some code in C and compile it using a Palm OS development tool such as CodeWarrior.