Edit

Permalink

Example on how to create permalinks.

In this example the HTML 5 History API is used to update the browser URL with the current zoom-level, center and rotation when the map is moved. Note that the History API is not supported in all browsers, one might consider to use a a polyfill.

Copy 
index.html<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Permalink</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=requestAnimationFrame,Element.prototype.classList,URL"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script src="index.js"></script>
  </body>
</html>
Copy 
index.jsimport 'ol/ol.css';
import Map from 'ol/Map';
import View from 'ol/View';
import TileLayer from 'ol/layer/Tile';
import OSM from 'ol/source/OSM';

// default zoom, center and rotation
var zoom = 2;
var center = [0, 0];
var rotation = 0;

if (window.location.hash !== '') {
  // try to restore center, zoom-level and rotation from the URL
  var hash = window.location.hash.replace('#map=', '');
  var parts = hash.split('/');
  if (parts.length === 4) {
    zoom = parseInt(parts[0], 10);
    center = [
      parseFloat(parts[1]),
      parseFloat(parts[2])
    ];
    rotation = parseFloat(parts[3]);
  }
}

var map = new Map({
  layers: [
    new TileLayer({
      source: new OSM()
    })
  ],
  target: 'map',
  view: new View({
    center: center,
    zoom: zoom,
    rotation: rotation
  })
});

var shouldUpdate = true;
var view = map.getView();
var updatePermalink = function() {
  if (!shouldUpdate) {
    // do not update the URL when the view was changed in the 'popstate' handler
    shouldUpdate = true;
    return;
  }

  var center = view.getCenter();
  var hash = '#map=' +
      view.getZoom() + '/' +
      Math.round(center[0] * 100) / 100 + '/' +
      Math.round(center[1] * 100) / 100 + '/' +
      view.getRotation();
  var state = {
    zoom: view.getZoom(),
    center: view.getCenter(),
    rotation: view.getRotation()
  };
  window.history.pushState(state, 'map', hash);
};

map.on('moveend', updatePermalink);

// restore the view state when navigating through the history, see
// https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onpopstate
window.addEventListener('popstate', function(event) {
  if (event.state === null) {
    return;
  }
  map.getView().setCenter(event.state.center);
  map.getView().setZoom(event.state.zoom);
  map.getView().setRotation(event.state.rotation);
  shouldUpdate = false;
});
Copy 
package.json{
  "name": "permalink",
  "dependencies": {
    "ol": "6.1.1"
  },
  "devDependencies": {
    "parcel": "1.11.0"
  },
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build --experimental-scope-hoisting --public-url . index.html"
  }
}