This example shows how to read data from a UTFGrid source.
Point to a country to see its name and flag.
Tiles made with TileMill. Hosting on mapbox.com or with open-source TileServer.<!DOCTYPE html>
<html lang="en">
<head>
<title>UTFGrid</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;
}
#country-name {
color: black;
font-size: 12pt;
font-weight: bold;
text-shadow: white 0.1em 0.1em 0.2em;
}
</style>
</head>
<body>
<div id="map" class="map"></div>
<div style="display: none;">
<!-- Overlay with the country info -->
<div id="country-info">
<div id="country-name"> </div>
<img id="country-flag" src="" />
</div>
</div>
<script src="index.js"></script>
</body>
</html>
import 'ol/ol.css';
import Map from 'ol/Map';
import Overlay from 'ol/Overlay';
import View from 'ol/View';
import TileLayer from 'ol/layer/Tile';
import TileJSON from 'ol/source/TileJSON';
import UTFGrid from 'ol/source/UTFGrid';
var key = 'Your Mapbox access token from https://mapbox.com/ here';
var mapLayer = new TileLayer({
source: new TileJSON({
url: 'https://api.tiles.mapbox.com/v4/mapbox.geography-class.json?secure&access_token=' + key
})
});
var gridSource = new UTFGrid({
url: 'https://api.tiles.mapbox.com/v4/mapbox.geography-class.json?secure&access_token=' + key
});
var gridLayer = new TileLayer({source: gridSource});
var view = new View({
center: [0, 0],
zoom: 1
});
var mapElement = document.getElementById('map');
var map = new Map({
layers: [mapLayer, gridLayer],
target: mapElement,
view: view
});
var infoElement = document.getElementById('country-info');
var flagElement = document.getElementById('country-flag');
var nameElement = document.getElementById('country-name');
var infoOverlay = new Overlay({
element: infoElement,
offset: [15, 15],
stopEvent: false
});
map.addOverlay(infoOverlay);
var displayCountryInfo = function(coordinate) {
var viewResolution = /** @type {number} */ (view.getResolution());
gridSource.forDataAtCoordinateAndResolution(coordinate, viewResolution,
function(data) {
// If you want to use the template from the TileJSON,
// load the mustache.js library separately and call
// info.innerHTML = Mustache.render(gridSource.getTemplate(), data);
mapElement.style.cursor = data ? 'pointer' : '';
if (data) {
flagElement.src = 'data:image/png;base64,' + data['flag_png'];
nameElement.innerHTML = data['admin'];
}
infoOverlay.setPosition(data ? coordinate : undefined);
});
};
map.on('pointermove', function(evt) {
if (evt.dragging) {
return;
}
var coordinate = map.getEventCoordinate(evt.originalEvent);
displayCountryInfo(coordinate);
});
map.on('click', function(evt) {
displayCountryInfo(evt.coordinate);
});
{
"name": "utfgrid",
"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"
}
}