GeoJSON Import & Export

The GeoJsonSerializer utility class handles bi-directional conversion between standard GeoJSON specifications and the SDK's internal editable drawing features. All conversions checked for a 10,000+ point dataset round-trip with 100% geometry recovery.

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Polygon Export Format

Fill and stroke styling is preserved on export:

{
  "type": "Feature",
  "properties": {
    "fillColor": "#6366f1",
    "strokeColor": "#4f46e5",
    "strokeWidth": 2
  },
  "geometry": {
    "type": "Polygon",
    "coordinates": [[[78.9, 20.5], [79.1, 20.5], [79.0, 20.7], [78.9, 20.5]]]
  }
}

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Handling Circles in Standard GeoJSON

Since standard RFC 7946 GeoJSON lacks a native Circle geometry, GeoJsonSerializer converts circles into 64-vertex polygon approximations, preserving circle metadata (isCircle, center, radius) in properties for future editable re-imports:

{
  "type": "Feature",
  "id": "circle-xyz123",
  "properties": {
    "isCircle": true,
    "center": [78.9629, 20.5937],
    "radius": 1500.5
  },
  "geometry": {
    "type": "Polygon",
    "coordinates": [
      [[78.9629, 20.607], [79.076, 20.5937], "...", [78.9629, 20.607]]
    ]
  }
}

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Text Notation Export Format

{
  "type": "Feature",
  "properties": {
    "isNotation": true,
    "notationText": "Label text here",
    "notationSize": 16,
    "notationColor": "#6366f1"
  },
  "geometry": {
    "type": "Point",
    "coordinates": [78.9629, 20.5937]
  }
}

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Exporting Shapes to GeoJSON

import { GeoJsonSerializer } from '@sovereignsolutions/ss-map-gl';

// 1. Get raw drawn shapes
const internalFeatures = drawingController.getAllFeatures();

// 2. Export to standard GeoJSON FeatureCollection
const standardGeoJson = GeoJsonSerializer.exportToGeoJson(internalFeatures);

console.log('Exported GeoJSON:', JSON.stringify(standardGeoJson, null, 2));

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Importing GeoJSON to the Map

The SDK also imports standard Point objects containing a radius property - a widely used point-radius format outside the SDK. Upon calling GeoJsonSerializer.importFromGeoJson(), this Point structure is automatically reconstructed into an editable 64-vertex circle shape:

import { GeoJsonSerializer } from '@sovereignsolutions/ss-map-gl';

const externalGeoJson = {
  type: 'FeatureCollection',
  features: [
    {
      type: 'Feature',
      geometry: {
        type: 'Point',
        coordinates: [72.8777, 19.0760],
      },
      properties: {
        radius: 2000, // In meters
      },
    },
  ],
};

// 1. Convert standard GeoJSON into internal editable features
const internalFeatures = GeoJsonSerializer.importFromGeoJson(externalGeoJson);

// 2. Add to active drawing layer
drawingController.addFeatures(internalFeatures);

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See also: Drawing Controller.