geojson_vi 1.0.5+4

GeoJSON package for Dart developers to create, read, update and delete the geospatial data interchange format.

example/geojson_vi_example.dart

import 'package:geojson_vi/geojson_vi.dart';

void main() {
  
  // ### Create a Feature with Point geometry
  
  // New GeoJSON
  final geoJSON = GeoJSON.create('example/data/new.geojson');

  // One position
  final pos = <double>[];
  pos.add(105.7743099);
  pos.add(21.0717561);
  // or pos.addAll([105.7743099,21.0717561]);

  // Create a Point geometry from one position
  final geom_point = GeoJSONPoint(pos);
  
  // Create a Feature
  final feature_point = GeoJSONFeature(geom_point);
  feature_point.properties['marker-color'] = '#7e7e7e';
  feature_point.properties['marker-size'] = 'medium';
  feature_point.properties['marker-symbol'] = 'college';
  feature_point.properties['title'] = 'Hanoi University of Mining and Geology';
  feature_point.properties['department'] = 'Geoinformation Technology';
  feature_point.properties['address'] = 'No.18 Vien Street - Duc Thang Ward- Bac Tu Liem District - Ha Noi';
  feature_point.properties['url'] = 'http://humg.edu.vn';

  // Add the feature to featureCollection
  geoJSON.featureCollection.features.add(feature_point);


  // ### Create a Feature with LineString geometry
  
  // LineString from 3 positions
  final pos1 = [105.7771289,21.0715458];
  final pos2 = [105.7745218,21.0715658];
  final pos3 = [105.7729125,21.0715358];
  
  // Create a LineString geometry from array of position
  final geom_line_string = GeoJSONLineString([pos1, pos2, pos3]);
  
  // Create a Feature 
  final feature_line_string = GeoJSONFeature(geom_line_string);
  feature_line_string.properties['stroke'] = '#7e7e7e';
  feature_line_string.properties['stroke-width'] = 2;
  feature_line_string.properties['stroke-opacity'] = 1;
  feature_line_string.properties['title'] = 'Vien St.';
  
  // Add the fearture to featureCollection
  geoJSON.featureCollection.features.add(feature_line_string);


  // ### Create a Feature with Polygon geometry
  
  // A linear ring is a closed LineString with four or more positions.
  // The first and last positions are equivalent, and they MUST contain
  // identical values; their representation SHOULD also be identical.
  final p01 = [105.7739666,21.0726795]; // The first position
  final p02 = [105.7739719,21.0721991];
  final p03 = [105.7743394,21.0721966];
  final p04 = [105.7743310,21.0725269];
  final p05 = [105.7742564,21.0726120];
  final p06 = [105.7741865,21.0726095];
  final p07 = [105.7741785,21.0726746];
  final p08 = [105.7739666,21.0726795]; // The last position

  //The exterior ring (boundary)
  final linerRing = [p01,p02,p03,p04,p05,p06,p07,p08];
  
  // Create a Polygon geometry from array of position
  final geom_polygon = GeoJSONPolygon([
    linerRing,
    // and others the interior rings (if present) bound holes within the surface
  ]);
  
  // Create a Feature
  final feature_polygon = GeoJSONFeature(geom_polygon);
  feature_polygon.properties['stroke'] = '#555555';
  feature_polygon.properties['stroke-width'] = 2;
  feature_polygon.properties['stroke-opacity'] = 1;
  feature_polygon.properties['fill'] = '#ab7942';
  feature_polygon.properties['fill-opacity'] = 0.5;
  feature_polygon.properties['title'] = 'HUMG\'s Office';

  // Add to featureCollection
  geoJSON.featureCollection.features.add(feature_polygon);

  geoJSON.save();
}