/// <summary>
/// Parses the specified <paramref name="json"/> object into an instance deriving from <see cref="GeoJsonObject"/>.
///
/// As the GeoJSON format specified the type of a
/// </summary>
/// <param name="json">The JSON object.</param>
/// <returns>An instance that derives from <see cref="GeoJsonObject"/>.</returns>
private static GeoJsonObject Parse(JObject json)
{
if (json == null)
{
return(null);
}
// Get the value of the "type" property
string type = json.GetString("type");
if (string.IsNullOrWhiteSpace(type))
{
throw new GeoJsonParseException("The JSON object doesn't specify a type", json);
}
// Parse the type into an enum
if (EnumUtils.TryParseEnum(type, out GeoJsonType result) == false)
{
throw new GeoJsonParseException($"Unknown type {type}", json);
}
switch (result)
{
case GeoJsonType.Feature:
return(GeoJsonFeature.Parse(json));
case GeoJsonType.FeatureCollection:
return(GeoJsonFeatureCollection.Parse(json));
case GeoJsonType.Point:
return(GeoJsonPoint.Parse(json));
case GeoJsonType.LineString:
return(GeoJsonLineString.Parse(json));
case GeoJsonType.Polygon:
return(GeoJsonPolygon.Parse(json));
case GeoJsonType.MultiPoint:
return(GeoJsonMultiPoint.Parse(json));
//case GeoJsonType.MultiLineString:
// return GeoJsonMultiLineString.Parse(obj);
case GeoJsonType.MultiPolygon:
return(GeoJsonMultiPolygon.Parse(json));
case GeoJsonType.GeometryCollection:
return(GeoJsonGeometryCollection.Parse(json));
default:
throw new GeoJsonParseException($"Unknown type {type}", json);
}
}
/// <inheritdoc />
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
{
return(null);
}
if (reader.TokenType != JsonToken.StartObject)
{
return(null);
}
JObject obj = JObject.Load(reader);
string type = obj.Value <string>("type");
switch (type?.ToLower())
{
case "feature":
return(GeoJsonFeature.Parse(obj));
case "featurecollection":
return(GeoJsonFeatureCollection.Parse(obj));
case "point":
return(GeoJsonPoint.Parse(obj));
case "multipoint":
return(GeoJsonMultiPoint.Parse(obj));
case "linestring":
return(GeoJsonLineString.Parse(obj));
case "multilinestring":
return(GeoJsonMultiLineString.Parse(obj));
case "polygon":
return(GeoJsonPolygon.Parse(obj));
case "multipolygon":
return(GeoJsonMultiPolygon.Parse(obj));
default:
if (objectType == typeof(GeoJsonProperties))
{
return(ReadJsonProperties(reader));
}
throw new GeoJsonParseException($"Unknown shape: {type}", obj);
}
}
public void Parse1()
{
const string json = "{\"type\":\"Feature\",\"geometry\":{\"type\":\"Point\",\"coordinates\":[9.536067,55.708116]}}";
GeoJsonFeature feature = GeoJsonFeature.Parse(json);
Assert.IsNotNull(feature);
Assert.IsNotNull(feature.Geometry);
Assert.IsNotNull(feature.Properties);
GeoJsonPoint point = feature.Geometry as GeoJsonPoint;
Assert.IsNotNull(point);
Assert.AreEqual(9.536067, point.X, "X");
Assert.AreEqual(55.708116, point.Y, "Y");
Assert.AreEqual(0, point.Altitude, "Altitude");
}
public void Parse2()
{
const string json = "{\"type\":\"Feature\",\"properties\":{\"name\":\"My feature\"},\"geometry\":{\"type\":\"Point\",\"coordinates\":[9.536067,55.708116,100]}}";
GeoJsonFeature feature = GeoJsonFeature.Parse(json);
Assert.IsNotNull(feature);
Assert.IsNotNull(feature.Geometry);
Assert.IsNotNull(feature.Properties);
GeoJsonPoint point = feature.Geometry as GeoJsonPoint;
Assert.IsNotNull(point);
Assert.AreEqual(9.536067, point.X, "X");
Assert.AreEqual(55.708116, point.Y, "Y");
Assert.AreEqual(100, point.Altitude, "Altitude");
Assert.AreEqual("My feature", feature.Properties.Name);
Assert.AreEqual(null, feature.Properties.Description);
}