Google Maps: how to get country, state/province/region, city given a lat/long value?
What you are looking for is called reverse geocoding. Google provides a server-side reverse geocoding service through the Google Geocoding API, which you should be able to use for your project.
This is how a response to the following request would look like:
http://maps.googleapis.com/maps/api/geocode/json?latlng=40.714224,-73.961452&sensor=false
Response:
{
"status": "OK",
"results": [ {
"types": [ "street_address" ],
"formatted_address": "275-291 Bedford Ave, Brooklyn, NY 11211, USA",
"address_components": [ {
"long_name": "275-291",
"short_name": "275-291",
"types": [ "street_number" ]
}, {
"long_name": "Bedford Ave",
"short_name": "Bedford Ave",
"types": [ "route" ]
}, {
"long_name": "New York",
"short_name": "New York",
"types": [ "locality", "political" ]
}, {
"long_name": "Brooklyn",
"short_name": "Brooklyn",
"types": [ "administrative_area_level_3", "political" ]
}, {
"long_name": "Kings",
"short_name": "Kings",
"types": [ "administrative_area_level_2", "political" ]
}, {
"long_name": "New York",
"short_name": "NY",
"types": [ "administrative_area_level_1", "political" ]
}, {
"long_name": "United States",
"short_name": "US",
"types": [ "country", "political" ]
}, {
"long_name": "11211",
"short_name": "11211",
"types": [ "postal_code" ]
} ],
"geometry": {
"location": {
"lat": 40.7142298,
"lng": -73.9614669
},
"location_type": "RANGE_INTERPOLATED",
"viewport": {
"southwest": {
"lat": 40.7110822,
"lng": -73.9646145
},
"northeast": {
"lat": 40.7173774,
"lng": -73.9583193
}
}
}
},
... Additional results[] ...
You can also opt to receive the response in xml instead of json, by simply substituting json for xml in the request URI:
http://maps.googleapis.com/maps/api/geocode/xml?latlng=40.714224,-73.961452&sensor=false
As far as I know, Google will also return the same name for address components, especially for high-level names like country names and city names. Nevertheless, keep in mind that while the results are very accurate for most applications, you could still find the occasional spelling mistake or ambiguous result.
You have a basic answer here: Get city name using geolocation
But for what you are looking for, i'd recommend this way.
Only if you also need administrative_area_level_1,to store different things for Paris, Texas, US and Paris, Ile-de-France, France and provide a manual fallback:
--
There is a problem in Michal's way, in that it takes the first result, not a particular one. He uses results[0]. The way I see fit (I just modified his code) is to take ONLY the result whose type is "locality", which is always present, even in an eventual manual fallback in case the browser does not support geolocation.
His way: fetched results are different from using http://maps.googleapis.com/maps/api/geocode/json?address=bucharest&sensor=false than from using http://maps.googleapis.com/maps/api/geocode/json?latlng=44.42514,26.10540&sensor=false (searching by name / searching by lat&lng)
This way: same fetched results.
<!DOCTYPE html>
<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>Reverse Geocoding</title>
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
var geocoder;
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(successFunction, errorFunction);
}
//Get the latitude and the longitude;
function successFunction(position) {
var lat = position.coords.latitude;
var lng = position.coords.longitude;
codeLatLng(lat, lng)
}
function errorFunction(){
alert("Geocoder failed");
}
function initialize() {
geocoder = new google.maps.Geocoder();
}
function codeLatLng(lat, lng) {
var latlng = new google.maps.LatLng(lat, lng);
geocoder.geocode({'latLng': latlng}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
//console.log(results);
if (results[1]) {
var indice=0;
for (var j=0; j<results.length; j++)
{
if (results[j].types[0]=='locality')
{
indice=j;
break;
}
}
alert('The good number is: '+j);
console.log(results[j]);
for (var i=0; i<results[j].address_components.length; i++)
{
if (results[j].address_components[i].types[0] == "locality") {
//this is the object you are looking for City
city = results[j].address_components[i];
}
if (results[j].address_components[i].types[0] == "administrative_area_level_1") {
//this is the object you are looking for State
region = results[j].address_components[i];
}
if (results[j].address_components[i].types[0] == "country") {
//this is the object you are looking for
country = results[j].address_components[i];
}
}
//city data
alert(city.long_name + " || " + region.long_name + " || " + country.short_name)
} else {
alert("No results found");
}
//}
} else {
alert("Geocoder failed due to: " + status);
}
});
}
</script>
</head>
<body onload="initialize()">
</body>
</html>
I used this question as a starting point for my own solution. Thought it was appropriate to contribute my code back since its smaller than tabacitu's
Dependencies:
- underscore.js
- https://github.com/estebanav/javascript-mobile-desktop-geolocation
- <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
Code:
if(geoPosition.init()){
var foundLocation = function(city, state, country, lat, lon){
//do stuff with your location! any of the first 3 args may be null
console.log(arguments);
}
var geocoder = new google.maps.Geocoder();
geoPosition.getCurrentPosition(function(r){
var findResult = function(results, name){
var result = _.find(results, function(obj){
return obj.types[0] == name && obj.types[1] == "political";
});
return result ? result.short_name : null;
};
geocoder.geocode({'latLng': new google.maps.LatLng(r.coords.latitude, r.coords.longitude)}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK && results.length) {
results = results[0].address_components;
var city = findResult(results, "locality");
var state = findResult(results, "administrative_area_level_1");
var country = findResult(results, "country");
foundLocation(city, state, country, r.coords.latitude, r.coords.longitude);
} else {
foundLocation(null, null, null, r.coords.latitude, r.coords.longitude);
}
});
}, { enableHighAccuracy:false, maximumAge: 1000 * 60 * 1 });
}