Get city name using geolocation

2019-01-02 16:59发布

问题:

I managed to get the user's latitude and longitude using html5 geolocation.

//Check if browser supports W3C Geolocation API
if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition(successFunction, errorFunction);
} 
//Get latitude and longitude;
function successFunction(position) {
    var lat = position.coords.latitude;
    var long = position.coords.longitude;
}

I want to display the city name, it seems the only way to get it is to use a reverse geolocation api. I read google's documentation for reverse geolocation but I don't know how to get the output on my site.

I don't know how to go use this: "http://maps.googleapis.com/maps/api/geocode/json?latlng='+lat+','+long+'&sensor=true" to display the city name on the page.

What is standard way to do it?

回答1:

You would do something like that using Google API.

Please note you must include the google maps library for this to work. Google geocoder returns a lot of address components so you must make an educated guess as to which one will have the city.

"administrative_area_level_1" is usually what you are looking for but sometimes locality is the city you are after.

Anyhow - more details on google response types can be found here and here.

Below is the code that should do the trick:

<!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]) {
         //formatted address
         alert(results[0].formatted_address)
        //find country name
             for (var i=0; i<results[0].address_components.length; i++) {
            for (var b=0;b<results[0].address_components[i].types.length;b++) {

            //there are different types that might hold a city admin_area_lvl_1 usually does in come cases looking for sublocality type will be more appropriate
                if (results[0].address_components[i].types[b] == "administrative_area_level_1") {
                    //this is the object you are looking for
                    city= results[0].address_components[i];
                    break;
                }
            }
        }
        //city data
        alert(city.short_name + " " + city.long_name)


        } else {
          alert("No results found");
        }
      } else {
        alert("Geocoder failed due to: " + status);
      }
    });
  }
</script> 
</head> 
<body onload="initialize()"> 

</body> 
</html> 


回答2:

Another approach to this is to use my service, http://ipinfo.io, which returns the city, region and country name based on the user's current IP address. Here's a simple example:

$.get("http://ipinfo.io", function(response) {
    console.log(response.city, response.country);
}, "jsonp");

Here's a more detailed JSFiddle example that also prints out the full response information, so you can see all of the available details: http://jsfiddle.net/zK5FN/2/



回答3:

Using html5 geolocation requires user permission. In case you don't want this, go for an external locator like https://geoip-db.com IPv6 is supported. No restrictions and unlimited requests allowed.

  • JSON: https://geoip-db.com/json
  • JSONP: https://geoip-db.com/jsonp

Example:

<!DOCTYPE html>
<html>
<head>
    <title>GEOIP DB - jQuery example</title>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
</head>
<body>
    <div>Country: <span id="country"></span>
    <div>State: <span id="state"></span>
    <div>City: <span id="city"></span>
    <div>Latitude: <span id="latitude"></span>
    <div>Longitude: <span id="longitude"></span>
    <div>IP: <span id="ip"></span>
    <script>
        $.ajax({
            url: "https://geoip-db.com/jsonp",
            jsonpCallback: "callback",
            dataType: "jsonp",
            success: function( location ) {
                $('#country').html(location.country_name);
                $('#state').html(location.state);
                $('#city').html(location.city);
                $('#latitude').html(location.latitude);
                $('#longitude').html(location.longitude);
                $('#ip').html(location.IPv4);  
            }
        });     
    </script>
</body>
</html>

For a pure javascript example, without using jQuery, check out this answer.



回答4:

Here is updated working version for me which will get City/Town, It looks like some fields are modified in the json response. Referring previous answers for this questions. ( Thanks to Michal & one more reference : Link

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) {
      if (results[1]) {
        var arrAddress = results;
        console.log(results);
        $.each(arrAddress, function(i, address_component) {
          if (address_component.types[0] == "locality") {
            console.log("City: " + address_component.address_components[0].long_name);
            itemLocality = address_component.address_components[0].long_name;
          }
        });
      } else {
        alert("No results found");
      }
    } else {
      alert("Geocoder failed due to: " + status);
    }
  });
}


回答5:

You can get the name of the city, country, street name and other geodata using the Google Maps Geocoding API

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <script type="text/javascript" src="https://code.jquery.com/jquery-2.2.3.js"></script>
</head>
<body>
    <script type="text/javascript">
        navigator.geolocation.getCurrentPosition(success, error);

        function success(position) {
            console.log(position.coords.latitude)
            console.log(position.coords.longitude)

            var GEOCODING = 'https://maps.googleapis.com/maps/api/geocode/json?latlng=' + position.coords.latitude + '%2C' + position.coords.longitude + '&language=en';

            $.getJSON(GEOCODING).done(function(location) {
                console.log(location)
            })

        }

        function error(err) {
            console.log(err)
        }
    </script>
</body>
</html>

and to display this data on the page using jQuery

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <script type="text/javascript" src="https://code.jquery.com/jquery-2.2.3.js"></script>
</head>
<body>

    <p>Country: <span id="country"></span></p>
    <p>State: <span id="state"></span></p>
    <p>City: <span id="city"></span></p>
    <p>Address: <span id="address"></span></p>

    <p>Latitude: <span id="latitude"></span></p>
    <p>Longitude: <span id="longitude"></span></p>

    <script type="text/javascript">
        navigator.geolocation.getCurrentPosition(success, error);

        function success(position) {

            var GEOCODING = 'https://maps.googleapis.com/maps/api/geocode/json?latlng=' + position.coords.latitude + '%2C' + position.coords.longitude + '&language=en';

            $.getJSON(GEOCODING).done(function(location) {
                $('#country').html(location.results[0].address_components[5].long_name);
                $('#state').html(location.results[0].address_components[4].long_name);
                $('#city').html(location.results[0].address_components[2].long_name);
                $('#address').html(location.results[0].formatted_address);
                $('#latitude').html(position.coords.latitude);
                $('#longitude').html(position.coords.longitude);
            })

        }

        function error(err) {
            console.log(err)
        }
    </script>
</body>
</html>


回答6:

geolocator.js can do that. (I'm the author).

Getting City Name (Limited Address)

geolocator.locateByIP(options, function (err, location) {
    console.log(location.address.city);
});

Getting Full Address Information

Example below will first try HTML5 Geolocation API to obtain the exact coordinates. If fails or rejected, it will fallback to Geo-IP look-up. Once it gets the coordinates, it will reverse-geocode the coordinates into an address.

var options = {
    enableHighAccuracy: true,
    fallbackToIP: true, // fallback to IP if Geolocation fails or rejected
    addressLookup: true
};
geolocator.locate(options, function (err, location) {
    console.log(location.address.city);
});

This uses Google APIs internally (for address lookup). So before this call, you should configure geolocator with your Google API key.

geolocator.config({
    language: "en",
    google: {
        version: "3",
        key: "YOUR-GOOGLE-API-KEY"
    }
});

Geolocator supports geo-location (via HTML5 or IP lookups), geocoding, address look-ups (reverse geocoding), distance & durations, timezone information and a lot more features...



回答7:

After some searching and piecing together a couple of different solutions along with my own stuff, I came up with this function:

function parse_place(place)
{
    var location = [];

    for (var ac = 0; ac < place.address_components.length; ac++)
    {
        var component = place.address_components[ac];

        switch(component.types[0])
        {
            case 'locality':
                location['city'] = component.long_name;
                break;
            case 'administrative_area_level_1':
                location['state'] = component.long_name;
                break;
            case 'country':
                location['country'] = component.long_name;
                break;
        }
    };

    return location;
}


回答8:

You can use https://ip-api.io/ to get city Name. It supports IPv6.

As a bonus it allows to check whether ip address is a tor node, public proxy or spammer.

Javascript Code:

$(document).ready(function () {
        $('#btnGetIpDetail').click(function () {
            if ($('#txtIP').val() == '') {
                alert('IP address is reqired');
                return false;
            }
            $.getJSON("http://ip-api.io/json/" + $('#txtIP').val(),
                 function (result) {
                     alert('City Name: ' + result.city)
                     console.log(result);
                 });
        });
    });

HTML Code

<script src="https://code.jquery.com/jquery-1.12.4.js"></script>
<div>
    <input type="text" id="txtIP" />
    <button id="btnGetIpDetail">Get Location of IP</button>
</div>

JSON Output

{
    "ip": "64.30.228.118",
    "country_code": "US",
    "country_name": "United States",
    "region_code": "FL",
    "region_name": "Florida",
    "city": "Fort Lauderdale",
    "zip_code": "33309",
    "time_zone": "America/New_York",
    "latitude": 26.1882,
    "longitude": -80.1711,
    "metro_code": 528,
    "suspicious_factors": {
        "is_proxy": false,
        "is_tor_node": false,
        "is_spam": false,
        "is_suspicious": false
    }
}


回答9:

Here is another go at it .. Adding more to the accepted answer possibly more comprehensive .. of course switch -case will make it look for elegant.

function parseGeoLocationResults(result) {
    const parsedResult = {}
    const {address_components} = result;

    for (var i = 0; i < address_components.length; i++) {
        for (var b = 0; b < address_components[i].types.length; b++) {
            if (address_components[i].types[b] == "street_number") {
                //this is the object you are looking for
                parsedResult.street_number = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "route") {
                //this is the object you are looking for
                parsedResult.street_name = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "sublocality_level_1") {
                //this is the object you are looking for
                parsedResult.sublocality_level_1 = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "sublocality_level_2") {
                //this is the object you are looking for
                parsedResult.sublocality_level_2 = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "sublocality_level_3") {
                //this is the object you are looking for
                parsedResult.sublocality_level_3 = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "neighborhood") {
                //this is the object you are looking for
                parsedResult.neighborhood = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "locality") {
                //this is the object you are looking for
                parsedResult.city = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "administrative_area_level_1") {
                //this is the object you are looking for
                parsedResult.state = address_components[i].long_name;
                break;
            }

            else if (address_components[i].types[b] == "postal_code") {
                //this is the object you are looking for
                parsedResult.zip = address_components[i].long_name;
                break;
            }
            else if (address_components[i].types[b] == "country") {
                //this is the object you are looking for
                parsedResult.country = address_components[i].long_name;
                break;
            }
        }
    }
    return parsedResult;
}


回答10:

As @PirateApp mentioned in his comment, it's explicitly against Google's Maps API Licensing to use the Maps API as you intend.

You have a number of alternatives, including downloading a Geoip database and querying it locally or using a third party API service, such as ipdata.co.

ipdata gives you the geolocation, organisation, currency, timezone, calling code, flag and Tor Exit Node status data from any IPv4 or IPv6 address.

And is scalable with 10 global endpoints each able to handle >10,000 requests per second!

This answer uses a 'test' API Key that is very limited and only meant for testing a few calls. Signup for your own Free API Key and get up to 1500 requests daily for development.

$.get("https://api.ipdata.co?api-key=test", function(response) {
  $("#ip").html("IP: " + response.ip);
  $("#city").html(response.city + ", " + response.region);
  $("#response").html(JSON.stringify(response, null, 4));
}, "jsonp");
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h1><a href="https://ipdata.co">ipdata.co</a> - IP geolocation API</h1>

<div id="ip"></div>
<div id="city"></div>
<pre id="response"></pre>

The fiddle; https://jsfiddle.net/ipdata/6wtf0q4g/922/



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