Meziantou.Framework.Geo.Maps 1.0.3

Meziantou.Framework.Geo.Maps

Loads offline map bundles: the borders, states and provinces, cities, rivers, lakes, coastline, land, ocean, seas and physical regions of a region (the world, a continent or a country), stored next to the application as folders of FlatGeobuf or GeoJSON files, or as GeoPackage files with Meziantou.Framework.Geo.Maps.GeoPackage. The layers are read as the features of Meziantou.Framework.Geo, and draw maps with Meziantou.Framework.Charts.

Usage

// The packages of bundles copy their regions to the maps folder next to the application
var map = MapCatalog.Default.GetMap("Switzerland");
Assert.Equal("Switzerland", map.Name);
Assert.StartsWith("© OpenStreetMap contributors", map.Attribution);

// The layers are read when they are loaded
var cantons = map.Load(MapLayer.StatesProvinces);
Assert.HasCount(26, cantons);
Assert.Contains("Vaud", cantons.Select(canton => (string?)canton.Properties["name"]));

var cities = map.Load(MapLayer.Cities);
var bern = cities.Single(city => city.Properties["name"] is "Bern");
Assert.Equal(true, bern.Properties["capital"]);

// Switzerland has no sea: it has no coastline, land or ocean layer
Assert.False(map.HasLayer(MapLayer.Coastline));

The package has no map of its own: add the package of the bundle of each region you need, such as Meziantou.Framework.Geo.Maps.Data.Switzerland, or build the bundles with the tools/Meziantou.Framework.Geo.Maps.Tool tool of the repository.

Formats

MapCatalog reads the folders of FlatGeobuf files (MapFormat.FlatGeobuf, the default of the tool) and of GeoJSON files (MapFormat.GeoJson). MapFormat.Write writes a map in a format, such as a GeoJSON copy for a web page:

// Write the map of a region in another format: a folder of GeoJSON files, which web libraries read
var output = Directory.CreateTempSubdirectory().FullName;
var map = MapCatalog.Default.GetMap("Switzerland");
MapFormat.GeoJson.Write(MapFormat.GeoJson.GetPath(output, map.Region), map);
Assert.True(File.Exists(Path.Combine(output, "Switzerland", "states-provinces.geojson")));

// The default catalog reads both folder formats
var copy = new MapCatalog(output).GetMap("Switzerland");
Assert.HasCount(26, copy.Load(MapLayer.StatesProvinces));

Data

The borders and subdivisions are derived from OpenStreetMap (© OpenStreetMap contributors, ODbL) through country-levels; the cities, rivers, lakes, coastline, land, ocean, marine areas and physical regions come from Natural Earth (public domain). Show Map.Attribution on the maps you publish.