Project file format

Mapboard GIS stores all project information within a Spatialite database. Spatialite is the spatial extension to SQLite, a small but capable database engine used by literally everyone. This open-source, well-documented basis allows project files to be created, read, and modified by outside software. Importantly, Spatialite files are supported natively by QGIS, ArcGIS, and Global Mapper, among other geospatial desktop environments. This means that there can always be a seamless transition between iPad and desktop mapping.

Internal design

Using a SQLite-based format for data storage, including for subsidiary information beyond the core spatial tables, results in a format that is self-documenting and extensible. This strategy for building app files is advocated by the SQLite project. The file must have the extension .mapboard-project to be recognized as a Mapboard project.

The .mapboard-project format can be read by a variety of software for working with SQLite databases, including graphical applications such as DB Browser for SQLite (recommended) and SQLite Studio. The Spatialite GUI application can open the spatial tables in the app. The file format can also be read using the sqlite3 command-line application and libraries for all major programming languages.

The project file structure is anchored by several key tables: linework, linework_type, polygon, and polygon_type. The mapboard_config table holds project configuration. When files are associated with the project (currently just the image mode), we use the SQLite Archive format to store them within the application database.

The author of the Spatialite library is due a lot of thanks for creating and maintaining the core technology that drives this application. Check out the Spatialite cookbook to learn more about the library.