FeatureCollection.fromWKT constructor

FeatureCollection.fromWKT(String wkt)

Creates a FeatureCollection from a WKT string.

Example:

FeatureCollection.fromWKT('GEOMETRYCOLLECTION(POINT(1 2), POINT(3 4))'); // FeatureCollection([Point(Coordinate(1, 2)), Point(Coordinate(3, 4))])

Implementation

factory FeatureCollection.fromWKT(String wkt) {
  final regexBody = RegExp(r'GEOMETRYCOLLECTION\w?\((.*)\)', multiLine: true);
  final match = regexBody.firstMatch(wkt);
  if (match == null) {
    throw ArgumentError('Invalid WKT');
  }

  final geometryString = match.group(1);
  final regexGeometry = RegExp(
      r'(\),[\s|\n]{0,2})(?=(POINT|MULTIPOINT|LINESTRING|MULTILINESTRING|POLYGON|MULTIPOLYGON))');
  final geometries = geometryString?.split(regexGeometry) ?? [];

  return FeatureCollection(
    geometries.map((g) {
      if (g.startsWith('POINT')) {
        return Point.fromWKT(g);
      } else if (g.startsWith('MULTIPOINT')) {
        return MultiPoint.fromWKT(g);
      } else if (g.startsWith('LINESTRING')) {
        return LineString.fromWKT(g);
      } else if (g.startsWith('MULTILINESTRING')) {
        return MultiLineString.fromWKT(g);
      } else if (g.startsWith('POLYGON')) {
        return Polygon.fromWKT(g);
      } else if (g.startsWith('MULTIPOLYGON')) {
        return MultiPolygon.fromWKT(g);
      } else {
        throw ArgumentError('Invalid geometry type');
      }
    }).toList(),
  );
}