dbe3643ffd070acdfbbc by ThomasG77

index.js

import 'ol/ol.css';
import Map from 'ol/Map';
import View from 'ol/View';
import Draw from 'ol/interaction/Draw';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer';
import {OSM, Vector as VectorSource} from 'ol/source';
import GeoJSON from 'ol/format/GeoJSON';
import {fromCircle} from 'ol/geom/Polygon';
import Circle from 'ol/geom/Circle';
import { saveAs } from 'file-saver';



var raster = new TileLayer({
  source: new OSM()
});

var source = new VectorSource({wrapX: false});

var vector = new VectorLayer({
  source: source
});

var map = new Map({
  layers: [raster, vector],
  target: 'map',
  view: new View({
    center: [-11000000, 4600000],
    zoom: 4
  })
});

var typeSelect = document.getElementById('type');
var exportGeoJSON = document.getElementById('export');
exportGeoJSON.addEventListener('click', function(evt) {
  console.log('clicked');

  var geojsonString = (new GeoJSON({dataProjection: 'EPSG:4326', featureProjection: 'EPSG:3857'})).writeFeatures(source.getFeatures().map(feature => {
  var feat = feature.clone();
  if (feat.getGeometry() instanceof Circle) {
    feat.setGeometry(fromCircle(feat.getGeometry()));
  }
  return feat;
}));
  var blob = new Blob([geojsonString], {type: "application/ vnd.geo+json;charset=utf-8"});
  saveAs(blob, "export.geojson");
  //console.log(geojsonString);
})

var draw; // global so we can remove it later
function addInteraction() {
  var value = typeSelect.value;
  if (value !== 'None') {
    draw = new Draw({
      source: source,
      type: typeSelect.value,
      freehand: true
    });
    map.addInteraction(draw);
  }
}


/**
 * Handle change event.
 */
typeSelect.onchange = function() {
  map.removeInteraction(draw);
  addInteraction();
};

addInteraction();

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Freehand Drawing</title>
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,URL"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <form class="form-inline">
      <label>Geometry type &nbsp;</label>
      <select id="type">
        <option value="LineString">LineString</option>
        <option value="Polygon">Polygon</option>
        <option value="Circle">Circle</option>
        <option value="None">None</option>
      </select>
    </form>
    <button type="button" id="export">Export</button>
    <script src="index.js"></script>
  </body>
</html>

package.json

{
  "name": "draw-freehand",
  "dependencies": {
    "file-saver": "^2.0.2",
    "ol": "6.3.1"
  },
  "devDependencies": {
    "parcel": "1.11.0"
  },
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build --experimental-scope-hoisting --public-url . index.html"
  }
}