It’s been awhile since I’ve open sourced any code (cough…XRG…cough) and I thought it was about time to contribute something new.

This code is a small collection of classes that will parse ESRI Shapefiles. As I’m getting further into the development of Seasonality Pro (which you can follow at the new Seasonality: Behind the Scenes blog), I thought it would be important to be able to show Shapefile data on a map. There are a few basic implementations out there (see iOS-Shapefile and Cocoa Shapefile), but I wanted a more modern code design, and something that was flexible enough to add expanded support in the future. So I dug up the Shapefile spec and got started.

The result after hacking on it for a few days is GSShapefile. It should work on both the Mac and iOS platforms, as long as you have ARC enabled in your project. GSShapefile takes an NSData object as its input, so it doesn’t make any assumption of whether the data is coming from a local file or somewhere online. After the file is parsed, you can retrieve the shape records and points associated with each shape. It really should be pretty easy to integrate with your own code.

I hope somebody finds it helpful.