How to get addresses (geocoding informations) from polygon in maps? - maps

Question

I was looking for a way to retrive all the addresses inside a polygon in a map (google map?). I saw in this post that someone said that is not possible..
I ask this: if is possible to retrive the address from a point on the map, why is not possible to do the same in a polygon? Can't you just: - set an hypoteticl grid in the area of the polygon - for every intersection point of the grid retrive the location address - store the address (if is already stored delete it).
Wouln't this method be workable? thanks Francesco

Answer 1

Looking around I'm almost find a way to do that, merging up various methods.. I'm new in js, so my code is probably full of dumb stuff..
Anyway, I reached a point where I managed to retrive my unique addresses into an array, but can't complete the job beacuse I always get the error of OVER_QUERY_LIMIT, beacuse I send too many requests as explainedin this page
So I think there is no way to do this, unless you want to spend a lot in buying the billing to unlock higher quotas, and this will be a very hard hit beacuse a method like this will require thousands of request each call.
Anyway, this is the code, inserted into the one found here , wich I got from Polygon Drawing and Getting Coordinates with Google Map API v3
Sorry again for the various newbie stuff you will find in it.
var arrAddress=[]; //global
var arrCoord=[]; //global
function selPoly(shape) { //after create polygon do the job
var latlngStr=[];
var lat,lng;
var polCoords = [];
posstr = "" + selectedShape.position;
if (typeof selectedShape.position == 'object') {
posstr = selectedShape.position.toUrlValue();
}
if (typeof selectedShape.getPath == 'function') {
var mycoord="";
var partlng, partlng;
for (var i = 0; i < selectedShape.getPath().getLength(); i++) {
// .toUrlValue(5) limits number of decimals, default is 6 but can do more
mycoord=selectedShape.getPath().getAt(i).toUrlValue();
latlngStr = mycoord.split(',');
//create array with polygon path
polCoords.push(new google.maps.LatLng(latlngStr[0] , latlngStr[1]));
//add 0s to lat
lat=latlngStr[0];
partlat = latlngStr[0].substring(latlngStr[0].indexOf(".") + 1);
switch(partlat.length) {
case 4:
lat =lat +"00";
break;
case 5:
lat =lat +"0";
break;
}
//add 0s to lng
lng=latlngStr[1];
partlng = latlngStr[1].substring(latlngStr[1].indexOf(".") + 1);
switch(partlng.length) {
case 4:
lng =lng +"00";
break;
case 5:
lng =lng +"0";
break;
}
arrCoord.push(lat+","+lng);
}
};
//find higher and lower lat and lng in the polygon, converting lan e lng to number
var maxlat=0, maxlng=0;minlat=99999999,minlng=9999999;
var latlngStr=[];
for(var i=0;i<arrCoord.length;i++) {
latlngStr = arrCoord[i].split(',');
console.log(latlngStr);
lat = parseInt(latlngStr[0].replace(".", ""));
console.log(lat);
lng = parseInt(latlngStr[1].replace(".", ""));
if (lat>maxlat){
maxlat=lat;
};
if (lng>maxlng){
maxlng=lng;
};
if (lat<minlat){
minlat=lat;
};
if (lng<maxlng){
minlng=lng;
};
};
//create new polygon with that path
var polygon = new google.maps.Polygon({
paths: polCoords,
strokeColor: '#FF0000',
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: '#FF0000',
fillOpacity: 0.35
});
//move from (minlan,minlng) every 100 horizontal until reach maxlan, then add 200 to lng and star again.
var coordinate;
var newlat="",newlng="";
for (var i=minlat;i<maxlat;i+=100){
for (var j=minlng;j<maxlng;j+=200){
//reconvert lat e lng from number to string
newlat=i.toString();
newlng=j.toString();
newlat=newlat.substring(0,newlat.length-6) + "." +newlat.substring(newlat.length-6,6);
newlng=newlng.substring(0,newlng.length-6) + "." +newlng.substring(newlng.length-6,6);
coordinate=newlat +"," + newlng;
//for every point find out if is inside the polygon
var isWithinPolygon = polygon.containsLatLng(parseFloat(newlat),parseFloat(newlng));
if(isWithinPolygon){
newgeocodeLatLng(function(addr){
if (arrAddress.length==0){arrAddress.push(addr);} else{
for (var i =0; i<arrAddress.length;i++){
var ok=0;
///if address (retrive only the street name) found from point is already in the array, don't put in it. i'm sure there is a better ay to do it....
if (arrAddress[i].split(',')[0]==addr.split(',')[0]){
ok=1;};
};
if(ok==0){arrAddress.push(addr);
};
};
},coordinate); //end newgeocodelatlng
}; //end if iswithpolygon
};//end for j
};//end for i
};
function newgeocodeLatLng(callback,mycoord) {
var address;
var latlngStr = mycoord.split(',');
getReverseGeocodingData(function(addr){
address=addr;
callback(address);
// console.log("address4=" + address);
},latlngStr[0], latlngStr[1]);
};
function getReverseGeocodingData(callback,lat, lng) {
var address="";
var latlng = new google.maps.LatLng(lat, lng);
// This is making the Geocode request
var geocoder = new google.maps.Geocoder();
geocoder.geocode({ 'latLng': latlng }, function (results, status) {
if (status !== google.maps.GeocoderStatus.OK) {
alert(status);
}
// This is checking to see if the Geoeode Status is OK before proceeding
if (status == google.maps.GeocoderStatus.OK) {
callback(results[0].formatted_address);
}
});
}