This example allows you to drag and drop GeoJSON onto the map. Download a sample GeoJSON file to test dragging from the device.
For more information about how to work with the map data layer, see the google.maps.Data class.
TypeScript
let map: google.maps.Map;
function initMap(): void {
// set up the map
map = new google.maps.Map(document.getElementById("map") as HTMLElement, {
center: new google.maps.LatLng(0, 0),
zoom: 4,
});
}
function loadGeoJsonString(geoString: string) {
try {
const geojson = JSON.parse(geoString) as any;
map.data.addGeoJson(geojson);
} catch (e) {
alert("Not a GeoJSON file!");
}
zoom(map);
}
/**
* Update a map's viewport to fit each geometry in a dataset
*/
function zoom(map: google.maps.Map) {
const bounds = new google.maps.LatLngBounds();
map.data.forEach((feature) => {
const geometry = feature.getGeometry();
if (geometry) {
processPoints(geometry, bounds.extend, bounds);
}
});
map.fitBounds(bounds);
}
/**
* Process each point in a Geometry, regardless of how deep the points may lie.
*/
function processPoints(
geometry: google.maps.LatLng | google.maps.Data.Geometry,
callback: any,
thisArg: google.maps.LatLngBounds
) {
if (geometry instanceof google.maps.LatLng) {
callback.call(thisArg, geometry);
} else if (geometry instanceof google.maps.Data.Point) {
callback.call(thisArg, geometry.get());
} else {
// @ts-ignore
geometry.getArray().forEach((g) => {
processPoints(g, callback, thisArg);
});
}
}
/* DOM (drag/drop) functions */
function initEvents() {
[...document.getElementsByClassName("file")].forEach((fileElement) => {
fileElement.addEventListener(
"dragstart",
(e: Event) => {
// @ts-ignore
e.dataTransfer.setData(
"text/plain",
JSON.stringify(files[Number((e.target as HTMLElement).dataset.value)])
);
console.log(e);
},
false
);
});
// set up the drag & drop events
const mapContainer = document.getElementById("map") as HTMLElement;
mapContainer.addEventListener("dragenter", addClassToDropTarget, false);
mapContainer.addEventListener("dragover", addClassToDropTarget, false);
mapContainer.addEventListener("drop", handleDrop, false);
mapContainer.addEventListener("dragleave", removeClassFromDropTarget, false);
}
function addClassToDropTarget(e: Event) {
e.stopPropagation();
e.preventDefault();
document.getElementById("map")!.classList.add("over");
return false;
}
function removeClassFromDropTarget(e: Event) {
document.getElementById("map")!.classList.remove("over");
}
function handleDrop(e: DragEvent) {
e.preventDefault();
e.stopPropagation();
removeClassFromDropTarget(e);
const files = (e.dataTransfer as DataTransfer).files;
if (files.length) {
// process file(s) being dropped
// grab the file data from each file
for (let i = 0, file; (file = files[i]); i++) {
const reader = new FileReader();
reader.onload = function (e) {
loadGeoJsonString(reader.result as string);
};
reader.onerror = function (e) {
console.error("reading failed");
};
reader.readAsText(file);
}
} else {
// process non-file (e.g. text or html) content being dropped
// grab the plain text version of the data
const plainText = (e.dataTransfer as DataTransfer).getData("text/plain");
console.log(plainText);
if (plainText) {
loadGeoJsonString(plainText);
}
}
// prevent drag event from bubbling further
return false;
}
function initialize() {
initMap();
initEvents();
}
const files = [
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "Polygon",
coordinates: [
[
[-99.49218749999999, -11.867350911459294],
[24.960937499999996, -11.867350911459294],
[24.960937499999996, 47.517200697839414],
[-99.49218749999999, 47.517200697839414],
[-99.49218749999999, -11.867350911459294],
],
],
},
},
],
},
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [81.2109375, 50.064191736659104],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [103.35937499999999, -47.98992166741417],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-46.05468749999999, 64.01449619484472],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-113.203125, 37.996162679728116],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-73.828125, -32.249974455863295],
},
},
],
},
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "LineString",
coordinates: [
[147.65625, -5.266007882805485],
[118.47656249999999, 43.83452678223682],
[80.85937499999999, -30.145127183376115],
[35.15625, 51.83577752045248],
[-15.468749999999998, -23.563987128451217],
[-29.53125, 44.33956524809713],
[-73.47656249999999, -32.842673631954305],
[-104.765625, 35.460669951495305],
],
},
},
],
},
];
JavaScript
let map;
function initMap() {
// set up the map
map = new google.maps.Map(document.getElementById("map"), {
center: new google.maps.LatLng(0, 0),
zoom: 4,
});
}
function loadGeoJsonString(geoString) {
try {
const geojson = JSON.parse(geoString);
map.data.addGeoJson(geojson);
} catch (e) {
alert("Not a GeoJSON file!");
}
zoom(map);
}
/**
* Update a map's viewport to fit each geometry in a dataset
*/
function zoom(map) {
const bounds = new google.maps.LatLngBounds();
map.data.forEach((feature) => {
const geometry = feature.getGeometry();
if (geometry) {
processPoints(geometry, bounds.extend, bounds);
}
});
map.fitBounds(bounds);
}
/**
* Process each point in a Geometry, regardless of how deep the points may lie.
*/
function processPoints(geometry, callback, thisArg) {
if (geometry instanceof google.maps.LatLng) {
callback.call(thisArg, geometry);
} else if (geometry instanceof google.maps.Data.Point) {
callback.call(thisArg, geometry.get());
} else {
geometry.getArray().forEach((g) => {
processPoints(g, callback, thisArg);
});
}
}
/* DOM (drag/drop) functions */
function initEvents() {
[...document.getElementsByClassName("file")].forEach((fileElement) => {
fileElement.addEventListener(
"dragstart",
(e) => {
e.dataTransfer.setData(
"text/plain",
JSON.stringify(files[Number(e.target.dataset.value)])
);
console.log(e);
},
false
);
});
// set up the drag & drop events
const mapContainer = document.getElementById("map");
mapContainer.addEventListener("dragenter", addClassToDropTarget, false);
mapContainer.addEventListener("dragover", addClassToDropTarget, false);
mapContainer.addEventListener("drop", handleDrop, false);
mapContainer.addEventListener("dragleave", removeClassFromDropTarget, false);
}
function addClassToDropTarget(e) {
e.stopPropagation();
e.preventDefault();
document.getElementById("map").classList.add("over");
return false;
}
function removeClassFromDropTarget(e) {
document.getElementById("map").classList.remove("over");
}
function handleDrop(e) {
e.preventDefault();
e.stopPropagation();
removeClassFromDropTarget(e);
const files = e.dataTransfer.files;
if (files.length) {
// process file(s) being dropped
// grab the file data from each file
for (let i = 0, file; (file = files[i]); i++) {
const reader = new FileReader();
reader.onload = function (e) {
loadGeoJsonString(reader.result);
};
reader.onerror = function (e) {
console.error("reading failed");
};
reader.readAsText(file);
}
} else {
// process non-file (e.g. text or html) content being dropped
// grab the plain text version of the data
const plainText = e.dataTransfer.getData("text/plain");
console.log(plainText);
if (plainText) {
loadGeoJsonString(plainText);
}
}
// prevent drag event from bubbling further
return false;
}
function initialize() {
initMap();
initEvents();
}
const files = [
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "Polygon",
coordinates: [
[
[-99.49218749999999, -11.867350911459294],
[24.960937499999996, -11.867350911459294],
[24.960937499999996, 47.517200697839414],
[-99.49218749999999, 47.517200697839414],
[-99.49218749999999, -11.867350911459294],
],
],
},
},
],
},
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [81.2109375, 50.064191736659104],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [103.35937499999999, -47.98992166741417],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-46.05468749999999, 64.01449619484472],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-113.203125, 37.996162679728116],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-73.828125, -32.249974455863295],
},
},
],
},
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "LineString",
coordinates: [
[147.65625, -5.266007882805485],
[118.47656249999999, 43.83452678223682],
[80.85937499999999, -30.145127183376115],
[35.15625, 51.83577752045248],
[-15.468749999999998, -23.563987128451217],
[-29.53125, 44.33956524809713],
[-73.47656249999999, -32.842673631954305],
[-104.765625, 35.460669951495305],
],
},
},
],
},
];
CSS
html {
height: 100%;
}
body {
height: 100%;
margin: 0;
padding: 0;
overflow: hidden;
}
#map {
height: 100%;
}
#map.over {
opacity: 0.5;
background-color: rgba(100, 100, 100, 0.5);
}
#sidebar {
flex-direction: column;
align-items: center;
justify-content: center;
overflow: auto;
}
.file {
display: flex;
flex-flow: column;
margin-top: 1em;
cursor: move;
text-align: center;
}
.file:hover .material-icons {
color: darkorange;
}
.file:hover .filename {
font-weight: bold;
}
.file .material-icons {
font-size: 50px;
color: orange;
}
.file .material-icons:hover {
color: darkorange;
}
.file .filename {
margin-top: 0.5em;
font-size: 20px;
color: #333333;
}
/* Optional: Makes the sample page fill the window. */
html,
body {
height: 100%;
margin: 0;
padding: 0;
}
#container {
height: 100%;
display: flex;
}
#sidebar {
flex-basis: 15rem;
flex-grow: 1;
padding: 1rem;
max-width: 30rem;
height: 100%;
box-sizing: border-box;
display: flex;
overflow: auto;
}
#map {
flex-basis: 0;
flex-grow: 4;
height: 100%;
}
HTML
<!DOCTYPE html>
<html>
<head>
<title>Data Layer: Drag and Drop GeoJSON</title>
<script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
<link
href="https://unpkg.com/material-components-web@6.0.0/dist/material-components-web.css"
rel="stylesheet"
/>
<link
rel="stylesheet"
href="https://fonts.googleapis.com/icon?family=Material+Icons"
/>
<link rel="stylesheet" type="text/css" href="./style.css" />
<script src="./index.js"></script>
</head>
<body>
<div id="container">
<div id="map"></div>
<div id="sidebar" class="mdc-typography">
<div class="file" draggable="true" data-value="0">
<span class="material-icons">text_snippet</span>
<div class="filename">polygons.geojson</div>
</div>
<div class="file" draggable="true" data-value="1">
<span class="material-icons">text_snippet</span>
<div class="filename">points.geojson</div>
</div>
<div class="file" draggable="true" data-value="2">
<span class="material-icons">text_snippet</span>
<div class="filename">polyline.geojson</div>
</div>
</div>
</div>
<!-- Async script executes immediately and must be after any DOM elements used in callback. -->
<script
src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initialize&libraries=&v=weekly"
async
></script>
</body>
</html>
let map;
function initMap() {
// set up the map
map = new google.maps.Map(document.getElementById("map"), {
center: new google.maps.LatLng(0, 0),
zoom: 4,
});
}
function loadGeoJsonString(geoString) {
try {
const geojson = JSON.parse(geoString);
map.data.addGeoJson(geojson);
} catch (e) {
alert("Not a GeoJSON file!");
}
zoom(map);
}
/**
* Update a map's viewport to fit each geometry in a dataset
*/
function zoom(map) {
const bounds = new google.maps.LatLngBounds();
map.data.forEach((feature) => {
const geometry = feature.getGeometry();
if (geometry) {
processPoints(geometry, bounds.extend, bounds);
}
});
map.fitBounds(bounds);
}
/**
* Process each point in a Geometry, regardless of how deep the points may lie.
*/
function processPoints(geometry, callback, thisArg) {
if (geometry instanceof google.maps.LatLng) {
callback.call(thisArg, geometry);
} else if (geometry instanceof google.maps.Data.Point) {
callback.call(thisArg, geometry.get());
} else {
geometry.getArray().forEach((g) => {
processPoints(g, callback, thisArg);
});
}
}
/* DOM (drag/drop) functions */
function initEvents() {
[...document.getElementsByClassName("file")].forEach((fileElement) => {
fileElement.addEventListener(
"dragstart",
(e) => {
e.dataTransfer.setData(
"text/plain",
JSON.stringify(files[Number(e.target.dataset.value)])
);
console.log(e);
},
false
);
});
// set up the drag & drop events
const mapContainer = document.getElementById("map");
mapContainer.addEventListener("dragenter", addClassToDropTarget, false);
mapContainer.addEventListener("dragover", addClassToDropTarget, false);
mapContainer.addEventListener("drop", handleDrop, false);
mapContainer.addEventListener("dragleave", removeClassFromDropTarget, false);
}
function addClassToDropTarget(e) {
e.stopPropagation();
e.preventDefault();
document.getElementById("map").classList.add("over");
return false;
}
function removeClassFromDropTarget(e) {
document.getElementById("map").classList.remove("over");
}
function handleDrop(e) {
e.preventDefault();
e.stopPropagation();
removeClassFromDropTarget(e);
const files = e.dataTransfer.files;
if (files.length) {
// process file(s) being dropped
// grab the file data from each file
for (let i = 0, file; (file = files[i]); i++) {
const reader = new FileReader();
reader.onload = function (e) {
loadGeoJsonString(reader.result);
};
reader.onerror = function (e) {
console.error("reading failed");
};
reader.readAsText(file);
}
} else {
// process non-file (e.g. text or html) content being dropped
// grab the plain text version of the data
const plainText = e.dataTransfer.getData("text/plain");
console.log(plainText);
if (plainText) {
loadGeoJsonString(plainText);
}
}
// prevent drag event from bubbling further
return false;
}
function initialize() {
initMap();
initEvents();
}
const files = [
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "Polygon",
coordinates: [
[
[-99.49218749999999, -11.867350911459294],
[24.960937499999996, -11.867350911459294],
[24.960937499999996, 47.517200697839414],
[-99.49218749999999, 47.517200697839414],
[-99.49218749999999, -11.867350911459294],
],
],
},
},
],
},
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [81.2109375, 50.064191736659104],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [103.35937499999999, -47.98992166741417],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-46.05468749999999, 64.01449619484472],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-113.203125, 37.996162679728116],
},
},
{
type: "Feature",
properties: {},
geometry: {
type: "Point",
coordinates: [-73.828125, -32.249974455863295],
},
},
],
},
{
type: "FeatureCollection",
features: [
{
type: "Feature",
properties: {},
geometry: {
type: "LineString",
coordinates: [
[147.65625, -5.266007882805485],
[118.47656249999999, 43.83452678223682],
[80.85937499999999, -30.145127183376115],
[35.15625, 51.83577752045248],
[-15.468749999999998, -23.563987128451217],
[-29.53125, 44.33956524809713],
[-73.47656249999999, -32.842673631954305],
[-104.765625, 35.460669951495305],
],
},
},
],
},
];
html {
height: 100%;
}
body {
height: 100%;
margin: 0;
padding: 0;
overflow: hidden;
}
#map {
height: 100%;
}
#map.over {
opacity: 0.5;
background-color: rgba(100, 100, 100, 0.5);
}
#sidebar {
flex-direction: column;
align-items: center;
justify-content: center;
overflow: auto;
}
.file {
display: flex;
flex-flow: column;
margin-top: 1em;
cursor: move;
text-align: center;
}
.file:hover .material-icons {
color: darkorange;
}
.file:hover .filename {
font-weight: bold;
}
.file .material-icons {
font-size: 50px;
color: orange;
}
.file .material-icons:hover {
color: darkorange;
}
.file .filename {
margin-top: 0.5em;
font-size: 20px;
color: #333333;
}
/* Optional: Makes the sample page fill the window. */
html,
body {
height: 100%;
margin: 0;
padding: 0;
}
#container {
height: 100%;
display: flex;
}
#sidebar {
flex-basis: 15rem;
flex-grow: 1;
padding: 1rem;
max-width: 30rem;
height: 100%;
box-sizing: border-box;
display: flex;
overflow: auto;
}
#map {
flex-basis: 0;
flex-grow: 4;
height: 100%;
}
<!DOCTYPE html>
<html>
<head>
<title>Data Layer: Drag and Drop GeoJSON</title>
<script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
<link
href="https://unpkg.com/material-components-web@6.0.0/dist/material-components-web.css"
rel="stylesheet"
/>
<link
rel="stylesheet"
href="https://fonts.googleapis.com/icon?family=Material+Icons"
/>
<!-- jsFiddle will insert css and js -->
</head>
<body>
<div id="container">
<div id="map"></div>
<div id="sidebar" class="mdc-typography">
<div class="file" draggable="true" data-value="0">
<span class="material-icons">text_snippet</span>
<div class="filename">polygons.geojson</div>
</div>
<div class="file" draggable="true" data-value="1">
<span class="material-icons">text_snippet</span>
<div class="filename">points.geojson</div>
</div>
<div class="file" draggable="true" data-value="2">
<span class="material-icons">text_snippet</span>
<div class="filename">polyline.geojson</div>
</div>
</div>
</div>
<!-- Async script executes immediately and must be after any DOM elements used in callback. -->
<script
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initialize&libraries=&v=weekly"
async
></script>
</body>
</html>
Try Sample
Clone Sample
Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application.
git clone -b sample-layer-data-dragndrop git@github.com:googlemaps/js-samples.gitcd js-samplesnpm inpm start
Other samples can be tried by switching to any branch beginning with sample-SAMPLE_NAME.
git checkout sample-SAMPLE_NAMEnpm inpm start