javascript - tipos - mapa de latitud y longitud

¿Cómo puedo obtener el nombre de la ciudad desde un punto de latitud y longitud?

Question

¿Hay alguna manera de obtener un nombre de ciudad desde un punto de latitud y longitud con la API de google api para javascript?

Si es así, ¿podría ver un ejemplo?

Answer 1

Aquí hay una solución moderna que usa una promesa:

function getAddress (latitude, longitude) {
    return new Promise(function (resolve, reject) {
        var request = new XMLHttpRequest();

        var method = ''GET'';
        var url = ''http://maps.googleapis.com/maps/api/geocode/json?latlng='' + latitude + '','' + longitude + ''&sensor=true'';
        var async = true;

        request.open(method, url, async);
        request.onreadystatechange = function () {
            if (request.readyState == 4) {
                if (request.status == 200) {
                    var data = JSON.parse(request.responseText);
                    var address = data.results[0];
                    resolve(address);
                }
                else {
                    reject(request.status);
                }
            }
        };
        request.send();
    });
};

Y llámalo así:

getAddress(lat, lon).then(console.log).catch(console.error);

La promesa devuelve el objeto de dirección en ''entonces'' o el código de estado de error en ''captura''

Answer 2

El siguiente código funciona bien para obtener el nombre de la ciudad (usando Google Map Geo API ):

HTML

<p><button onclick="getLocation()">Get My Location</button></p>
<p id="demo"></p>
<script src="http://maps.google.com/maps/api/js?key=YOUR_API_KEY"></script>

GUIÓN

var x=document.getElementById("demo");
function getLocation(){
    if (navigator.geolocation){
        navigator.geolocation.getCurrentPosition(showPosition,showError);
    }
    else{
        x.innerHTML="Geolocation is not supported by this browser.";
    }
}

function showPosition(position){
    lat=position.coords.latitude;
    lon=position.coords.longitude;
    displayLocation(lat,lon);
}

function showError(error){
    switch(error.code){
        case error.PERMISSION_DENIED:
            x.innerHTML="User denied the request for Geolocation."
        break;
        case error.POSITION_UNAVAILABLE:
            x.innerHTML="Location information is unavailable."
        break;
        case error.TIMEOUT:
            x.innerHTML="The request to get user location timed out."
        break;
        case error.UNKNOWN_ERROR:
            x.innerHTML="An unknown error occurred."
        break;
    }
}

function displayLocation(latitude,longitude){
    var geocoder;
    geocoder = new google.maps.Geocoder();
    var latlng = new google.maps.LatLng(latitude, longitude);

    geocoder.geocode(
        {''latLng'': latlng}, 
        function(results, status) {
            if (status == google.maps.GeocoderStatus.OK) {
                if (results[0]) {
                    var add= results[0].formatted_address ;
                    var  value=add.split(",");

                    count=value.length;
                    country=value[count-1];
                    state=value[count-2];
                    city=value[count-3];
                    x.innerHTML = "city name is: " + city;
                }
                else  {
                    x.innerHTML = "address not found";
                }
            }
            else {
                x.innerHTML = "Geocoder failed due to: " + status;
            }
        }
    );
}

Answer 3

En node.js podemos usar node-geocoder npm module para obtener la dirección de lat, lng.,

geo.js

var NodeGeocoder = require(''node-geocoder'');

var options = {
  provider: ''google'',
  httpAdapter: ''https'', // Default
  apiKey: '' '', // for Mapquest, OpenCage, Google Premier
  formatter: ''json'' // ''gpx'', ''string'', ...
};

var geocoder = NodeGeocoder(options);

geocoder.reverse({lat:28.5967439, lon:77.3285038}, function(err, res) {
  console.log(res);
});

salida:

nodo geo.js

[ { formattedAddress: ''C-85B, C Block, Sector 8, Noida, Uttar Pradesh 201301, India'',
    latitude: 28.5967439,
    longitude: 77.3285038,
    extra: 
     { googlePlaceId: ''ChIJkTdx9vzkDDkRx6LVvtz1Rhk'',
       confidence: 1,
       premise: ''C-85B'',
       subpremise: null,
       neighborhood: ''C Block'',
       establishment: null },
    administrativeLevels: 
     { level2long: ''Gautam Buddh Nagar'',
       level2short: ''Gautam Buddh Nagar'',
       level1long: ''Uttar Pradesh'',
       level1short: ''UP'' },
    city: ''Noida'',
    country: ''India'',
    countryCode: ''IN'',
    zipcode: ''201301'',
    provider: ''google'' } ]

Answer 4

Esto se llama geocodificación inversa

• Documentación de Google:

  http://code.google.com/apis/maps/documentation/geocoding/#ReverseGeocoding .

• Ejemplo de llamada al servicio web de geocodificación de Google:

  http://maps.googleapis.com/maps/api/geocode/json?latlng=40.714224,-73.961452&sensor=true

Answer 5

Igual que @Sanchit Gupta.

en esta parte

if (results[0]) {
 var add= results[0].formatted_address ;
 var  value=add.split(",");
 count=value.length;
 country=value[count-1];
 state=value[count-2];
 city=value[count-3];
 x.innerHTML = "city name is: " + city;
}

solo consola la matriz de resultados

if (results[0]) {
 console.log(results[0]);
 // choose from console whatever you need.
 var city = results[0].address_components[3].short_name;
 x.innerHTML = "city name is: " + city;
}

Answer 6

Aquí hay una muestra completa:

<!DOCTYPE html>
<html>
  <head>
    <title>Geolocation API with Google Maps API</title>
    <meta charset="UTF-8" />
  </head>
  <body>
    <script>
      function displayLocation(latitude,longitude){
        var request = new XMLHttpRequest();

        var method = ''GET'';
        var url = ''http://maps.googleapis.com/maps/api/geocode/json?latlng=''+latitude+'',''+longitude+''&sensor=true'';
        var async = true;

        request.open(method, url, async);
        request.onreadystatechange = function(){
          if(request.readyState == 4 && request.status == 200){
            var data = JSON.parse(request.responseText);
            var address = data.results[0];
            document.write(address.formatted_address);
          }
        };
        request.send();
      };

      var successCallback = function(position){
        var x = position.coords.latitude;
        var y = position.coords.longitude;
        displayLocation(x,y);
      };

      var errorCallback = function(error){
        var errorMessage = ''Unknown error'';
        switch(error.code) {
          case 1:
            errorMessage = ''Permission denied'';
            break;
          case 2:
            errorMessage = ''Position unavailable'';
            break;
          case 3:
            errorMessage = ''Timeout'';
            break;
        }
        document.write(errorMessage);
      };

      var options = {
        enableHighAccuracy: true,
        timeout: 1000,
        maximumAge: 0
      };

      navigator.geolocation.getCurrentPosition(successCallback,errorCallback,options);
    </script>
  </body>
</html>