简体   繁体   中英

Google maps API - add marker by address javascript

I have database of places with addresses and I want to add markers on google maps.

It shows only the default marker, seems like the geocoder.geocode() does nothing. For an example I'm trying to add a marker on " New York City", with no success.

<script>
    var geocoder;
    var map;
    var address = "new york city";
    geocoder = new google.maps.Geocoder();
    function initMap() {
        var uluru = { lat: -25.363, lng: 131.044 };
        var map = new google.maps.Map(document.getElementById('map'), {
            zoom: 4,
            center: uluru
        });
        var marker = new google.maps.Marker({
            position: uluru,
            map: map
        });
        codeAddress(address);

    }

    function codeAddress(address) {

        geocoder.geocode({ 'address': address }, function (results, status) {
            if (status == 'OK') {
                    var marker = new google.maps.Marker({
                    position: address,
                    map: map
                });
            } else {
                alert('Geocode was not successful for the following reason: ' + status);
            }
        });
    }


</script>
<script src="https://maps.googleapis.com/maps/api/js?key=XXX&callback=initMap"
    async defer></script>

The reason why you are not getting the expected result is because there is incorrect codes placement in the example you provided. You are trying to get a new instance of Google Maps API Geocoder before Google Maps is fully loaded. Hence, Google Maps API Geocoder will not work because of this Uncaught ReferenceError: google is not defined . You should get a new instance of Google Maps API Geocoder inside the initMap() function.

You can check Maps JavaScript API Geocoding to learn more.

You can also check Best Practices When Geocoding Addresses .

Please also note that you should not include your API_KEY when posting Google Maps APi related questions.

Here's the whole code:

<!DOCTYPE html>
<html>
  <head>
    <title>Geocoding service</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <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 geocoder;
      var map;
      var address = "new york city";
      function initMap() {
        var map = new google.maps.Map(document.getElementById('map'), {
          zoom: 8,
          center: {lat: -34.397, lng: 150.644}
        });
        geocoder = new google.maps.Geocoder();
        codeAddress(geocoder, map);
      }

      function codeAddress(geocoder, map) {
        geocoder.geocode({'address': address}, function(results, status) {
          if (status === 'OK') {
            map.setCenter(results[0].geometry.location);
            var marker = new google.maps.Marker({
              map: map,
              position: results[0].geometry.location
            });
          } else {
            alert('Geocode was not successful for the following reason: ' + status);
          }
        });
      }
    </script>
    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap">
    </script>
  </body>
</html>

Live demo here .

Hope it helps!

There were several errors in your code. Normally, it should looks OK now:

var geocoder;
var map;
var address = "new york city";

function initMap() {
    geocoder = new google.maps.Geocoder();

    var uluru = { lat: -25.363, lng: 131.044 };
    map = new google.maps.Map(document.getElementById('map'), {
        zoom: 4,
        center: uluru
    });
    var marker = new google.maps.Marker({
        position: uluru,
        map: map
    });
    codeAddress(address);

}

function codeAddress(address) {

    geocoder.geocode({ 'address': address }, function (results, status) {
        console.log(results);
        var latLng = {lat: results[0].geometry.location.lat (), lng: results[0].geometry.location.lng ()};
        console.log (latLng);
        if (status == 'OK') {
            var marker = new google.maps.Marker({
                position: latLng,
                map: map
            });
            console.log (map);
        } else {
            alert('Geocode was not successful for the following reason: ' + status);
        }
    });
}

This is a list of your errors:

  • You have to initialize your geocode when the google maps api is fully loaded. It means that you have to put this line of code: geocoder = new google.maps.Geocoder(); in the initMap () .
  • When you initialize the map you have to refer to a global variable. In your code, you create a new variable map in your function. But, you have to pass by the global's variable map.
  • When, you want to get the position of the geocoder's result, you have to pass by this line of code: results[0].geometry.location.lat () .

You may refer to the documentation .

Tell me if you have some questions.

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM