Develop Reference

Marker Clustering on Google Maps with JSON multi markers

I've created a map with multi markers from a JSON file. I'm trying to add a marker cluster, but I'm ending up with the cluster and markers showing at the same time.
This is what I see at the moment:
I've added the script below to my index.html page:
<script src="https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/markerclusterer.js"></script>
This is the relevant part of my maps.js file:
let map;
let jsonData = "assets/Data/maps.json";
const countries = [
{ lat: 48.857497, lng: 2.347628, zoom: 5, name: "France" },
//Brazil
{ lat: -15.793889, lng: -47.882778, zoom: 5, name: "Brazil" }
];
function initMap() {
const mapOptions = {
center: {
lat: 9.072264,
lng: 7.491302
},
zoom: 2,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map"), mapOptions);
countries.forEach(function (data) {
let countriesMarker = new google.maps.Marker({
map: map,
position: { lat: data.lat, lng: data.lng },
title: data.name
});
$("#selectlocation").append('<option value="' + [data.lat, data.lng, data.zoom].join('|') + '">' + data.name + '</option>');
});
let infowindow = new google.maps.InfoWindow();
//Method found on StackOverflow: https://stackoverflow.com/questions/28606149/load-data-from-json-file-into-map-markers-in-google-maps
$.getJSON(jsonData, function (jsonMarkers) {
$.each(jsonMarkers.markers, function (key, data) {
let latLng = new google.maps.LatLng(data.lat, data.lng);
let marker = new google.maps.Marker({
position: latLng,
map: map,
title: data.title
});
var clusterMarkers = jsonMarkers.markers.map(function (location) {
return new google.maps.Marker({
position: location
});
});
var markerCluster = new MarkerClusterer(map, clusterMarkers,
{ imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m' });
});
});
}

You have multiple issues.
As #xomena indicated you are creating the markers twice, remove one of those sets of code.
You are creating a MarkerClusterer for each marker. Move the creation of the MarkerClusterer out of the loop that creates the markers.
Something like this should work:
$.each(jsonMarkers.markers, function (key, data) {
let latLng = new google.maps.LatLng(data.lat, data.lng);
let marker = new google.maps.Marker({
position: latLng,
map: map,
title: data.title
});
clusterMarkers.push(marker);
});
var markerCluster = new MarkerClusterer(map, clusterMarkers,
{ imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m'
});
proof of concept fiddle
code snippet:
let map;
let jsonData = "assets/Data/maps.json";
const countries = [
{ lat: 48.857497, lng: 2.347628, zoom: 5, name: "France" },
//Brazil
{ lat: -15.793889, lng: -47.882778, zoom: 5, name: "Brazil" }
];
function initMap() {
const mapOptions = {
center: {
lat: -19.072264,
lng: 117.491302
},
zoom: 1,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map"), mapOptions);
countries.forEach(function (data) {
let countriesMarker = new google.maps.Marker({
map: map,
position: { lat: data.lat, lng: data.lng },
title: data.name
});
$("#selectlocation").append('<option value="' + [data.lat, data.lng, data.zoom].join('|') + '">' + data.name + '</option>');
});
let infowindow = new google.maps.InfoWindow();
let clusterMarkers = [];
//Method found on StackOverflow: https://stackoverflow.com/questions/28606149/load-data-from-json-file-into-map-markers-in-google-maps
// $.getJSON(jsonData, function (jsonMarkers) {
var jsonMarkers = {markers: [
{lat: -31.563910, lng: 147.154312},
{lat: -33.718234, lng: 150.363181},
{lat: -33.727111, lng: 150.371124},
{lat: -33.848588, lng: 151.209834},
{lat: -33.851702, lng: 151.216968},
{lat: -34.671264, lng: 150.863657},
{lat: -35.304724, lng: 148.662905},
{lat: -36.817685, lng: 175.699196},
{lat: -36.828611, lng: 175.790222},
{lat: -37.750000, lng: 145.116667},
{lat: -37.759859, lng: 145.128708},
{lat: -37.765015, lng: 145.133858},
{lat: -37.770104, lng: 145.143299},
{lat: -37.773700, lng: 145.145187},
{lat: -37.774785, lng: 145.137978},
{lat: -37.819616, lng: 144.968119},
{lat: -38.330766, lng: 144.695692},
{lat: -39.927193, lng: 175.053218},
{lat: -41.330162, lng: 174.865694},
{lat: -42.734358, lng: 147.439506},
{lat: -42.734358, lng: 147.501315},
{lat: -42.735258, lng: 147.438000},
{lat: -43.999792, lng: 170.463352}
]};
$.each(jsonMarkers.markers, function (key, data) {
let latLng = new google.maps.LatLng(data.lat, data.lng);
if (!data.title)
data.title = ""+key;
let marker = new google.maps.Marker({
position: latLng,
map: map,
title: data.title
});
clusterMarkers.push(marker);
});
var markerCluster = new MarkerClusterer(map, clusterMarkers,
{ imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m'
});
// });
}
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#map {
height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html, body {
height: 100%;
margin: 0;
padding: 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="map"></div>
<script src="https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/markerclusterer.js"></script>
<!-- Replace the value of the key parameter with your own API key. -->
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap">
</script>

Getting marker info from markerclusterer

I have pushed markers into the a markerClusterer. When I click on the markerClusterer I want to display the info of the nmarkers in the cluster. However, when I use the getMarkers() method, it does not give me the info that I stored in marker, only data about the marker itself. Is there any way that I can implement this? https://codesandbox.io/s/joey-gmaps-c5kdf
const markerCluster = new MarkerClusterer(map, [],
{ imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m' });
google.maps.event.addListener(markerCluster, 'clusterclick', function (c) {
console.log('Number of managed markers in cluster: ' + c.getSize());
var m = c.getMarkers();
for (i in m) {
console.log(Object.values(m[i]));
console.log(m[i].getTitle());
console.log(m[i].toString());
}
var p = [];
for (var i = 0; i < m.length; i++) {
p.push(m[i]);
}
});

You can get your markers' information using getMarkers so there may be an issue somewhere in your code implementation that you haven't posted.
Try the following jsfiddle based off of Google's example.
JS code below:
function initMap() {
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: {
lat: -28.024,
lng: 140.887
}
});
var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var markers = locations.map(function(location, i) {
return new google.maps.Marker({
position: location,
label: labels[i % labels.length],
title: location.lat.toString() + "," + location.lng.toString(),
myObj: { myKey: i }
});
});
var markerCluster = new MarkerClusterer(map, markers, {
imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m'
});
google.maps.event.addListener(markerCluster, 'clusterclick', function(c) {
console.log('Number of managed markers in cluster: ' + c.getSize());
var m = c.getMarkers();
for (let i in m) {
console.log(m[i].getLabel());
console.log(m[i].getTitle());
console.log(m[i].myObj.myKey);
}
});
}
var locations = [{
lat: -31.563910,
lng: 147.154312
},
{
lat: -33.718234,
lng: 150.363181
},
{
lat: -33.727111,
lng: 150.371124
},
{
lat: -33.848588,
lng: 151.209834
},
{
lat: -33.851702,
lng: 151.216968
},
{
lat: -34.671264,
lng: 150.863657
},
{
lat: -35.304724,
lng: 148.662905
},
{
lat: -36.817685,
lng: 175.699196
},
{
lat: -36.828611,
lng: 175.790222
},
{
lat: -37.750000,
lng: 145.116667
},
{
lat: -37.759859,
lng: 145.128708
},
{
lat: -37.765015,
lng: 145.133858
},
{
lat: -37.770104,
lng: 145.143299
},
{
lat: -37.773700,
lng: 145.145187
},
{
lat: -37.774785,
lng: 145.137978
},
{
lat: -37.819616,
lng: 144.968119
},
{
lat: -38.330766,
lng: 144.695692
},
{
lat: -39.927193,
lng: 175.053218
},
{
lat: -41.330162,
lng: 174.865694
},
{
lat: -42.734358,
lng: 147.439506
},
{
lat: -42.734358,
lng: 147.501315
},
{
lat: -42.735258,
lng: 147.438000
},
{
lat: -43.999792,
lng: 170.463352
}
]
If e.g. you click on the blue cluster #3, you'll get the following output logged in the console:
Number of managed markers in cluster: 3
T
-42.734358,147.439506
U
-42.734358,147.501315
V
-42.735258,147.438
Edit: This error appears to be typescript related. There's a solution in related thread custom property with google marker in type script
Please try the code below:
for (var i = 0; i < features.length; i++) {
const marker2 = new google.maps.Marker({
position: features[i].position,
icon: icons[features[i].type].icon,
animation: google.maps.Animation.DROP,
map: map
});
marker2.set("customInfo", features[i].location);
console.log("Marker222223", marker2["customInfo"]);
markerCluster.addMarker(marker2);
}
Hope this helps!

While creating markers add object into marker so that each marker will have asociated object with it i.e. customInfo
var marker = new google.maps.Marker({
position: accident_LatLng,
title: accident_title,
map: map,
customInfo: object,
});
to Access marker object use below code. I have created custom array to store marker object.
var markers = cluster.getMarkers();
var markerCustom = [];
for (var i = 0; i < markers.length; i++) {
markerCustom.push(cluster.markers_[i].customInfo)
}
Hope this helps
Reference https://medium.com/#sunil.jadhav38/implementing-marker-clustering-is-angular-using-google-charts-6b62a33f3b61

Google Map Clustering not working with single location

I am using Google Map Clustering and opening Info Windows after clicking on particular cluster using clusterclick which is working absolutely fine.
However, when I have single location, its not going inside clusterclick event and hence I am unable to open my Info Window.
I am trying to add below events but its not firing when I have single location as data.
google.maps.event.addListener(markers, 'click', (function (markers) {
alert('markersclick');
})(markers));
google.maps.event.addListener(map, 'click', function () {
alert('mapclick');
});
Here is my full source code (I have not added Info Window code because as of not even above events not firing).
<div id="map"></div>
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=MY_API_KEY">
</script>
<script src="https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/markerclusterer.js"></script>
<script>
function initMap() {
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: {lat: -28.024, lng: 140.887}
});
// Create an array of alphabetical characters used to label the markers.
var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var markers = locations.map(function(location, i) {
return new google.maps.Marker({
position: location,
label: labels[i % labels.length]
});
});
google.maps.event.addListener(markers, 'click', (function (markers) {
alert('markersclick');
})(markers));
google.maps.event.addListener(map, 'click', function () {
alert('mapclick');
});
// Add a marker clusterer to manage the markers.
var markerCluster = new MarkerClusterer(map, markers,
{imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m',
gridSize: 100,
zoomOnClick: true,
maxZoom: 10});
google.maps.clusterclick.addListener(markerCluster, "clusterclick", function(cluster, event) {
alert('hey');
});
}
var locations = [
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312},
{lat: -31.563910, lng: 147.154312}
];
initMap();
</script>
<style>
#map {
height: 100%;
}
</style>
If I change my locations array to something like this.
var locations = [
{lat: -31.563910, lng: 147.154312},
];
Then my clusterclick not firing as well as markers click event.
Also I am getting an error saying..
TypeError: google.maps.clusterclick is undefined
But I can have records like this.
Can someone guide me what I am doing wrong here ? Why its not working with single location ?

In the code you posted, markers is an array of google.maps.Marker objects. You can't add the listener on the array. You have to loop through your array and add the listener to each Marker individually.
function initMap() {
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: {
lat: -28.024,
lng: 140.887
}
});
// Create an array of alphabetical characters used to label the markers.
var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var locations = [{
lat: -31.563510,
lng: 147.154312
},
{
lat: -31.563610,
lng: 147.154312
},
{
lat: -31.563710,
lng: 147.154312
},
{
lat: -31.563810,
lng: 147.154312
}
];
var markers = [];
var infowindow = new google.maps.InfoWindow();
for (var i = 0; i < locations.length; i++) {
var marker = new google.maps.Marker({
position: locations[i],
map: map,
label: labels[i % labels.length]
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.setContent('Label: ' + this.getLabel());
infowindow.open(map, this);
});
markers.push(marker);
}
// Add a marker clusterer to manage the markers.
var markerCluster = new MarkerClusterer(map, markers, {
imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m',
gridSize: 100,
zoomOnClick: true,
maxZoom: 10
});
}
initMap();
#map {
height: 200px;
}
<div id="map"></div>
<script src="https://maps.googleapis.com/maps/api/js"></script>
<script src="https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/markerclusterer.js"></script>

Grouping markers near together with the same cluster size by google map

I want to group all markers near together with the same cluster size using google map.
I tried MarkerClusterer supported by Google Map, but the cluster size are different.
Is there any example for me?
Thanks for your help.

Understanding marker clustering
The MarkerClusterer library uses the grid-based clustering
technique that divides the map into squares of a certain size (the
size changes at each zoom level), and groups the markers into each
square grid. It creates a cluster at a particular marker, and adds
markers that are in its bounds to the cluster. It repeats this process
until all markers are allocated to the closest grid-based marker
clusters based on the map's zoom level. If markers are in the bounds
of more than one existing cluster, the Maps JavaScript API determines
the marker's distance from each cluster, and adds it to the closest
cluster.
You can set a MarkerClusterer option to adjust the cluster
position to reflect the average distance between all the markers that
are contained within it. You can also customize the
MarkerClusterer to modify other parameters like the grid size, the cluster
icon, cluster text, among others.
Take a look at below example:
I have used gridSize parameter to set a grouping value to my markers. This way you can achieve what you're looking for.
function initMap() {
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: {
lat: -28.024,
lng: 140.887
}
});
// Create an array of alphabetical characters used to label the markers.
var labels = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
// Add some markers to the map.
// Note: The code uses the JavaScript Array.prototype.map() method to
// create an array of markers based on a given "locations" array.
// The map() method here has nothing to do with the Google Maps API.
var markers = locations.map(function(location, i) {
return new google.maps.Marker({
position: location,
label: labels[i % labels.length]
});
});
// Add a marker clusterer to manage the markers.
var markerCluster = new MarkerClusterer(map, markers, {
imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m',
gridSize: 10
});
}
var locations = [{
lat: -31.563910,
lng: 147.154312
},
{
lat: -33.718234,
lng: 150.363181
},
{
lat: -33.727111,
lng: 150.371124
},
{
lat: -33.848588,
lng: 151.209834
},
{
lat: -33.851702,
lng: 151.216968
},
{
lat: -34.671264,
lng: 150.863657
},
{
lat: -35.304724,
lng: 148.662905
},
{
lat: -36.817685,
lng: 175.699196
},
{
lat: -36.828611,
lng: 175.790222
},
{
lat: -37.750000,
lng: 145.116667
},
{
lat: -37.759859,
lng: 145.128708
},
{
lat: -37.765015,
lng: 145.133858
},
{
lat: -37.770104,
lng: 145.143299
},
{
lat: -37.773700,
lng: 145.145187
},
{
lat: -37.774785,
lng: 145.137978
},
{
lat: -37.819616,
lng: 144.968119
},
{
lat: -38.330766,
lng: 144.695692
},
{
lat: -39.927193,
lng: 175.053218
},
{
lat: -41.330162,
lng: 174.865694
},
{
lat: -42.734358,
lng: 147.439506
},
{
lat: -42.734358,
lng: 147.501315
},
{
lat: -42.735258,
lng: 147.438000
},
{
lat: -43.999792,
lng: 170.463352
},
{
lat: -43.998792,
lng: 170.463352
},
{
lat: -43.999792,
lng: 170.413352
},
{
lat: -43.999000,
lng: 170.463000
}
]
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#map {
height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html,
body {
height: 100%;
margin: 0;
padding: 0;
}
<script src="https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/markerclusterer.js">
</script>
<script async defer src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBplDzEjv3SUmKPKj0IY-Iq4u_nB3z2Q1I&callback=initMap">
</script>
<div id="map"></div>
For an advance example, please take a look at this -> An example of MarkerClusterer v3 and for all examples, click here.

Google Maps. Overlay over map excluding the area

I'm using the Google Maps JavaScript API and I have to gray out the whole map excluding two dots on the map (ideally the line between two dots). The dot itself it's a GM coordinates.
As result I expect something similar with image below:

I can give you a hint.
If you array<array<LatLng>> to Polygon, you can make a hole polygon.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<style type="text/css">
#map_canvas {
width: 600px;
height: 400px;
border: 1px solid gray;
}
</style>
<script src="https://maps.googleapis.com/maps/api/js?language=ja"></script>
<script>
function initialize() {
var mapDiv = document.getElementById("map_canvas");
var map = new google.maps.Map(mapDiv, {
mapTypeId : google.maps.MapTypeId.ROADMAP
});
var paths = [[
{lat: 41.795692, lng: 140.756214},
{lat: 41.795492, lng: 140.756150},
{lat: 41.794700, lng: 140.757051},
{lat: 41.795556, lng: 140.757813},
{lat: 41.795764, lng: 140.757759},
{lat: 41.796140, lng: 140.758349},
{lat: 41.796044, lng: 140.758628},
{lat: 41.796468, lng: 140.759819},
{lat: 41.797283, lng: 140.759014},
{lat: 41.797243, lng: 140.758746},
{lat: 41.797811, lng: 140.758478},
{lat: 41.797915, lng: 140.758714},
{lat: 41.798995, lng: 140.758532},
{lat: 41.798611, lng: 140.757158},
{lat: 41.798459, lng: 140.757105},
{lat: 41.798403, lng: 140.756343},
{lat: 41.798587, lng: 140.756246},
{lat: 41.798763, lng: 140.754884},
{lat: 41.797795, lng: 140.754959},
{lat: 41.797667, lng: 140.755152},
{lat: 41.797067, lng: 140.754970},
{lat: 41.797035, lng: 140.754648},
{lat: 41.796180, lng: 140.753993},
{lat: 41.795892, lng: 140.755302},
{lat: 41.796004, lng: 140.755517}
], [
{lat: 41.79873502198214,lng: 140.75676172883607},
{lat: 41.79916701538921, lng: 140.75850996560666},
{lat: 41.79914485048169, lng: 140.7587355674591},
{lat: 41.7990097958377, lng: 140.75889128372955},
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