OpenLayers Nasıl Kullanılır ?

openlayers.ts

fetch('/data.json')
  .then(res => res.json())
  .then(geojson => {
    const reader = new GeoJSON({ featureProjection: 'EPSG:3857' });
    const features = reader.readFeatures(geojson);
    const vectorSource = new VectorSource({ features });
    map.addLayer(new VectorLayer({ source: vectorSource }))
  })
  .catch((e) => {
    alert('hata Oluştu!');
  });