how to get UK postcode from latitude and longitude? - php

Question

I need a way to find the postcode of a UK location if I know its latitude and longitude.
For example:
address:Old Deer Park, Richmond, Greater London TW9 2SL, United Kingdom
Latitude = 51.4691, Longitude = -0.2963
Using this information I need a way to programmatically retrieve that location's postcode.

Answer 1

The problem you're trying to solve is called reverse geocoding. Just look at the Google maps documentation, which gives examples. It boils down to a URL with a latlng paramater, you have a choice of XML or JSON. There can be many results, so you'll have to loop over the returned structure and pick the most appropriate.
http://maps.googleapis.com/maps/api/geocode/json?latlng=51.4691,-0.2963&sensor=false
Example usage using CURL + JSON.
function getPostcode($lat, $lng) {
$returnValue = NULL;
$ch = curl_init();
$url = "http://maps.googleapis.com/maps/api/geocode/json?latlng=${lat},${lng}&sensor=false";
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
$result = curl_exec($ch);
$json = json_decode($result, TRUE);
if (isset($json['results'])) {
foreach ($json['results'] as $result) {
foreach ($result['address_components'] as $address_component) {
$types = $address_component['types'];
if (in_array('postal_code', $types) && sizeof($types) == 1) {
$returnValue = $address_component['short_name'];
}
}
}
}
return $returnValue;
}
echo getPostcode(51.4691, -0.2963);

Answer 2

It isn't a part of Google maps - but there's a UK postcode API here:
http://www.uk-postcodes.com/api.php
It allows you to send it a request including lat and lon of a position and it will return the UK postcode for that location.
No idea if it works, but worth a try!

Answer 3

i have already use this code: how to get postcode special uk USing this code ..
and the estimated journey time for from_address to to_address .
<style>
.ui-autocomplete {background-color: white;width: 300px;border: 1px solid #cfcfcf;list-style-type: none;padding-left: 0px}
#intro-text{margin:20px 0}
#map_canvas {width: 720px;height: 200px;margin-top:20px;clear:both;display:none}
#from_box {margin-left:0px}
#to_box, #from_box {float:left;margin-left:10px}
#img_arrow {float:left;margin:30px 50px 0 50px}
#results{margin: 20px 0 10px 0; overflow:hidden}
#distance_direct{float:left;width:40%;border:1px solid black;margin-left:60px;height:90px}
#distance_road{float:left;width:40%;border-right:1px solid black; border-top:1px solid black; border-bottom:1px solid black;height:90px}
.ui-menu-item a {color:black;font-weight:bold;cursor:pointer}
</style>
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/jquery-ui.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
var geocoder = new google.maps.Geocoder();
// This function formats numbers by adding commas
function numberFormat(nStr,prefix){
var prefix = prefix || '';
nStr += '';
x = nStr.split('.');
x1 = x[0];
x2 = x.length > 1 ? '.' + x[1] : '';
var rgx = /(\d+)(\d{3})/;
while (rgx.test(x1))
x1 = x1.replace(rgx, '$1' + ',' + '$2');
return prefix + x1 + x2;
}
$("#from_address").autocomplete({
//This bit uses the geocoder to fetch address values
source: function(request, response) {
geocoder.geocode( {'address': request.term }, function(results, status) {
response($.map(results, function(item) {
return {
label: item.formatted_address,
value: item.formatted_address,
//latitude: item.geometry.location.lat(),
//longitude: item.geometry.location.lng()
}
}));
})
}
});
$("#to_address").autocomplete({
//This bit uses the geocoder to fetch address values
source: function(request, response) {
geocoder.geocode( {'address': request.term }, function(results, status) {
response($.map(results, function(item) {
return {
label: item.formatted_address,
value: item.formatted_address,
//latitude: item.geometry.location.lat(),
//longitude: item.geometry.location.lng()
}
}));
})
}
});
$('#get_results').click(function() {
if($('#from_address').val() == "" || $('#from_address').val() == "") {
$('#results').hide();
$('#map_canvas').hide();
$('#error_msg').show().html('Please make sure you have entered both a "From" and "To" address.');
return;
} else {
$('#error_msg').hide();
}
var location1;
var location2;
var formatted_from_address;
var formatted_to_address
$('#crow_dist').empty();
$('#drive_dist').empty();
geocoder.geocode( { 'address': $('#from_address').val() }, function(results, status ) {
if (status == google.maps.GeocoderStatus.OK) {
//location of first address (latitude + longitude)
location1 = results[0].geometry.location;
formatted_from_address = results[0].formatted_address;
$('#from_address').val( formatted_from_address );
//////////////////////////////////////////////
geocoder.geocode( { 'address': $('#to_address').val() }, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
//location of first address (latitude + longitude)
location2 = results[0].geometry.location;
formatted_to_address = results[0].formatted_address;
$('#to_address').val(formatted_to_address);
var latlng = new google.maps.LatLng((location1.lat()+location2.lat())/2,(location1.lng()+location2.lng())/2);
var myOptions = {
zoom:10,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
//Make sure maps shows both markers
var southWest = new google.maps.LatLng(location1.lat(),location1.lng());
var northEast = new google.maps.LatLng(location2.lat(),location2.lng());
var bounds = new google.maps.LatLngBounds(southWest,northEast);
document.getElementById("lat1").value = southWest;
document.getElementById("lat2").value = northEast;
map.fitBounds(bounds);
// show route between the points
directionsService = new google.maps.DirectionsService();
directionsDisplay = new google.maps.DirectionsRenderer({
suppressMarkers: true,
suppressInfoWindows: false
});
directionsDisplay.setMap(map);
var request = {
origin:location1,
destination:location2,
travelMode: google.maps.DirectionsTravelMode.DRIVING
};
directionsService.route(request, function(response, status) {
if (status == google.maps.DirectionsStatus.OK) {
directionsDisplay.setDirections(response);
distance = numberFormat( Math.round( (response.routes[0].legs[0].distance.value) * 0.000621371192 ) );
$("#drive_dist").html('<div style="font-weight:bold;font-size:1.6em;margin-bottom:5px">' + distance + ' mi.</div><div style="font-style:italic">Get Directions</div>');
} else {
$("#drive_dist").html('<div style="font-weight:bold;font-size:1.6em;margin-bottom:5px">Not Available</div>');
}
document.getElementById("distance1").value = distance;
});
$('#directionsPanel').empty();
directionsDisplay.setPanel(document.getElementById("directionsPanel"));
var marker1 = new google.maps.Marker({
map: map,
position: location1,
title: "From: " + $('#from_address').val()
});
var marker2 = new google.maps.Marker({
map: map,
position: location2,
title: "To: " + $('#to_address').val()
});
//DD=$('#from_address').val();
// create the text to be shown in the infowindows
var text1 = '<div style="width:100px"><b>From:</b> '+formatted_from_address+'</div>';
var text2 = '<div style="width:100px"><b>To:</b>'+formatted_to_address+'</div>';
// create info boxes for the two markers
var infowindow1 = new google.maps.InfoWindow({
content: text1
});
var infowindow2 = new google.maps.InfoWindow({
content: text2
});
// add action events so the info windows will be shown when the marker is clicked
google.maps.event.addListener(marker1, 'click', function() {
infowindow1.open(map,marker1);
});
google.maps.event.addListener(marker2, 'click', function() {
infowindow2.open(map,marker2);
});
function toRad(deg) {
return deg * Math.PI/180;
}
// compute distance between the two points
var R = 6371; // Radius of the earth in km
var dLat = toRad(location2.lat()-location1.lat());
var dLon = toRad(location2.lng()-location1.lng());
var dLat1 = toRad(location1.lat());
var dLat2 = toRad(location2.lat());
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(dLat1) * Math.cos(dLat1) *
Math.sin(dLon/2) * Math.sin(dLon/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = (R * c) * 0.621371192; // Distance in miles;
$("#crow_dist").html('<div style="font-weight:bold;font-size:1.6em;margin-bottom:5px">' + numberFormat( Math.round(d) ) + ' mi.</div><div style="font-style:italic">"As the Crow Flies"</div>');
$('#map_canvas').show();
} else {
alert("Geocode for Address 2 was not successful for the following reason: " + status);
}
});
} else {
alert("Geocode for Address 1 was not successful for the following reason: " + status);
}
});
$('#results').show();
});
if($('#from_address').val() != '' || $('#to_address').val() != '') {
$('#get_results').trigger('click');
}
});
</script>
<div id="map_canvas"></div>