How to remove or clear Google map markers via JavaScript?

Question

I am following this tutorial . This tutorial is working perfect for me. However I can't remove or clear the existing markers.

I have tried

map.clear();

and

for (var i = 0; i < markers.length; i++) {
          markers[i].setMap(null);
        }

but nothing works. I have provided the whole code below. I am not a good web programmer, So it will be best to edit this code.

    <!DOCTYPE html >
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <title>Using MySQL and PHP with Google Maps</title>
    <style>
      /* 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;
      }
    </style>
  </head>

  <body>
    <div id="map"></div>

    <script>
      var customLabel = {
        restaurant: {
          label: 'R'
        },
        bar: {
          label: 'B'
        }
      };

        function initMap() {
        var map = new google.maps.Map(document.getElementById('map'), {
          center: new google.maps.LatLng(-33.863276, 151.207977),
          zoom: 12
        });
        var infoWindow = new google.maps.InfoWindow;

          // Change this depending on the name of your PHP or XML file
          downloadUrl('https://storage.googleapis.com/mapsdevsite/json/mapmarkers2.xml', function(data) {
            var xml = data.responseXML;
            var markers = xml.documentElement.getElementsByTagName('marker');
            Array.prototype.forEach.call(markers, function(markerElem) {
              var id = markerElem.getAttribute('id');
              var name = markerElem.getAttribute('name');
              var address = markerElem.getAttribute('address');
              var type = markerElem.getAttribute('type');
              var point = new google.maps.LatLng(
                  parseFloat(markerElem.getAttribute('lat')),
                  parseFloat(markerElem.getAttribute('lng')));

              var infowincontent = document.createElement('div');
              var strong = document.createElement('strong');
              strong.textContent = name
              infowincontent.appendChild(strong);
              infowincontent.appendChild(document.createElement('br'));

              var text = document.createElement('text');
              text.textContent = address
              infowincontent.appendChild(text);
              var icon = customLabel[type] || {};
              var marker = new google.maps.Marker({
                map: map,
                position: point,
                label: icon.label
              });
              marker.addListener('click', function() {
                infoWindow.setContent(infowincontent);
                infoWindow.open(map, marker);
              });
            });
          });
        }



      function downloadUrl(url, callback) {
        var request = window.ActiveXObject ?
            new ActiveXObject('Microsoft.XMLHTTP') :
            new XMLHttpRequest;

        request.onreadystatechange = function() {
          if (request.readyState == 4) {
            request.onreadystatechange = doNothing;
            callback(request, request.status);
          }
        };

        request.open('GET', url, true);
        request.send(null);
      }

      function doNothing() {}
    </script>
    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap">
    </script>
  </body>
</html>

Answer 1

Your markers array is not an array of google.maps.Marker . Your array holds xmlnodes. You have to store the markers you're creating in the foreach method of the xmlnodes array in a proper variable. eg:

var mapMarkers = [];

function initMap() {
    mapMarkers = [];
    var map ...

    downloadUrl('https://storage.googleapis.com/mapsdevsite/json/mapmarkers2.xml', function (data) {
        var xml = data.responseXML;
        var markers = xml.documentElement.getElementsByTagName('marker');
        Array.prototype.forEach.call(markers, function (markerElem) {
            var id = markerElem.getAttribute('id');

            ...

            var marker = new google.maps.Marker({
                map: map,
                position: point,
                label: icon.label
            });
            marker.addListener('click', function () {
                infoWindow.setContent(infowincontent);
                infoWindow.open(map, marker);
            });
            mapMarkers.push(marker)
        });
    });
}

function downloadUrl(url, callback) {
    ...
}

Now you can iterate over mapMarkers to delete the markers from the map.

How to remove or clear Google map markers via JavaScript?

Question

1 answers

solution1
1 ACCPTED 2017-07-15 15:40:59

How to remove or clear Google map markers via JavaScript?

Question

1 answers

solution1 1 ACCPTED 2017-07-15 15:40:59

solution1
1 ACCPTED 2017-07-15 15:40:59