openlayers/examples/drag-and-drop-custom-kmz.js

import Map from '../src/ol/Map.js';
import View from '../src/ol/View.js';
import {
  DragAndDrop,
  defaults as defaultInteractions,
} from '../src/ol/interaction.js';
import {GPX, GeoJSON, IGC, KML, TopoJSON} from '../src/ol/format.js';
import {OSM, Vector as VectorSource} from '../src/ol/source.js';
import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';

// Create functions to extract KML and icons from KMZ array buffer,
// which must be done synchronously.

const zip = new JSZip();

function getKMLData(buffer) {
  let kmlData;
  zip.load(buffer);
  const kmlFile = zip.file(/\.kml$/i)[0];
  if (kmlFile) {
    kmlData = kmlFile.asText();
  }
  return kmlData;
}

function getKMLImage(href) {
  const index = window.location.href.lastIndexOf('/');
  if (index !== -1) {
    const kmlFile = zip.file(href.slice(index + 1));
    if (kmlFile) {
      return URL.createObjectURL(new Blob([kmlFile.asArrayBuffer()]));
    }
  }
  return href;
}

// Define a KMZ format class by subclassing ol/format/KML

class KMZ extends KML {
  constructor(opt_options) {
    const options = opt_options || {};
    options.iconUrlFunction = getKMLImage;
    super(options);
  }

  getType() {
    return 'arraybuffer';
  }

  readFeature(source, options) {
    const kmlData = getKMLData(source);
    return super.readFeature(kmlData, options);
  }

  readFeatures(source, options) {
    const kmlData = getKMLData(source);
    return super.readFeatures(kmlData, options);
  }
}

// Set up map with Drag and Drop interaction

const dragAndDropInteraction = new DragAndDrop({
  formatConstructors: [KMZ, GPX, GeoJSON, IGC, KML, TopoJSON],
});

const map = new Map({
  interactions: defaultInteractions().extend([dragAndDropInteraction]),
  layers: [
    new TileLayer({
      source: new OSM(),
    }),
  ],
  target: 'map',
  view: new View({
    center: [0, 0],
    zoom: 2,
  }),
});

dragAndDropInteraction.on('addfeatures', function (event) {
  const vectorSource = new VectorSource({
    features: event.features,
  });
  map.addLayer(
    new VectorLayer({
      source: vectorSource,
    })
  );
  map.getView().fit(vectorSource.getExtent());
});

const displayFeatureInfo = function (pixel) {
  const features = [];
  map.forEachFeatureAtPixel(pixel, function (feature) {
    features.push(feature);
  });
  if (features.length > 0) {
    const info = [];
    let i, ii;
    for (i = 0, ii = features.length; i < ii; ++i) {
      const description =
        features[i].get('description') ||
        features[i].get('name') ||
        features[i].get('_name') ||
        features[i].get('layer');
      if (description) {
        info.push(description);
      }
    }
    document.getElementById('info').innerHTML = info.join('<br/>') || '&nbsp';
  } else {
    document.getElementById('info').innerHTML = '&nbsp;';
  }
};

map.on('pointermove', function (evt) {
  if (evt.dragging) {
    return;
  }
  const pixel = map.getEventPixel(evt.originalEvent);
  displayFeatureInfo(pixel);
});

map.on('click', function (evt) {
  displayFeatureInfo(evt.pixel);
});

// Sample data download

const link = document.getElementById('download');

function download(fullpath, filename) {
  fetch(fullpath)
    .then(function (response) {
      return response.blob();
    })
    .then(function (blob) {
      link.href = URL.createObjectURL(blob);
      link.download = filename;
      link.click();
    });
}

document.getElementById('download-kmz').addEventListener('click', function () {
  download('data/kmz/iceland.kmz', 'iceland.kmz');
});