Developing Extensions

Extensions allow you to expand the range of data formats, GPS receivers, rangefinders, cameras, projections, and datum transformations supported in ArcPad. For example, if your application requires data in an unsupported map projection, you could write an extension to accomplish this. You can also create utility extensions that expose any desired low level functionality, normally accessible only via C/C++ code, to ArcPad scripts.

Here is a sample of extensions and their purpose.

• Layer: provide a range of support for each new data format including file identification, layer opening and closing, layer rendering, editing, identifying, and hyperlinking.
• GPS: provide support for additional GPS devices that ArcPad does not support out of the box.
• Rangefinder: provide support for additional rangefinders.
• Camera: provide support for additional cameras.
• Projection: provide support for additional projections.
• Datum: provide support for additional datum transformations.
• AUX: provide support for any serial port device that can communicate with ArcPad's AUX port.

Implementing different sets of functions and properties allows you to choose how much support to add.

Extensions are always compiled as platform specific Dynamic Link Libraries (DLLs). Once an extension is installed, the new functionality appears to the ArcPad user as any other built-in functionality.

Creating Extensions

Extensions are developed as Windows DLLs and are generally written in C or C++. External tools, such as a compiler and debugger, are required to create extensions.