Delphi ActiveX Requires Chilkat v11.1.0+

Google Maps Geolocation Request

See more REST Examples

Demonstrates how make a Google Maps Geolocation REST API request. Delphi ActiveX

var
success: Integer;
rest: TChilkatRest;
bTls: Integer;
port: Integer;
bAutoReconnect: Integer;
json: TChilkatJsonObject;
aCellTowers: TChilkatJsonArray;
oCellTower: TChilkatJsonObject;
aWifi: TChilkatJsonArray;
oPoint: TChilkatJsonObject;
responseJson: WideString;
jsonResp: TChilkatJsonObject;
jsonLoc: TChilkatJsonObject;
latitude: WideString;
longitude: WideString;
accuracy: WideString;

begin
success := 0;

//  This example duplicates the following CURL request:
//  curl -d @your_filename.json -H "Content-Type: application/json" -i "https://www.googleapis.com/geolocation/v1/geolocate?key=YOUR_API_KEY"

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

rest := TChilkatRest.Create(Self);

//  Connect to the Google API REST server.
bTls := 1;
port := 443;
bAutoReconnect := 1;
success := rest.Connect('www.googleapis.com',port,bTls,bAutoReconnect);

//  Add the Content-Type request header.
rest.AddHeader('Content-Type','application/json');

//  Add your API key as a query parameter
rest.AddQueryParam('key','YOUR_API_KEY');

//  The JSON query is contained in the body of the HTTP POST.
//  This is a sample query (which we'll dynamically build in this example)
//  { 
//   "homeMobileCountryCode": 310,
//   "homeMobileNetworkCode": 260,
//   "radioType": "gsm",
//   "carrier": "T-Mobile",
//   "cellTowers": [
//    {
//     "cellId": 39627456,
//     "locationAreaCode": 40495,
//     "mobileCountryCode": 310,
//     "mobileNetworkCode": 260,
//     "age": 0,
//     "signalStrength": -95
//    }
//   ],
//   "wifiAccessPoints": [
//    { 
//     "macAddress": "01:23:45:67:89:AB",
//     "signalStrength": 8,
//     "age": 0,
//     "signalToNoiseRatio": -65,
//     "channel": 8
//    },
//    { 
//     "macAddress": "01:23:45:67:89:AC",
//     "signalStrength": 4,
//     "age": 0
//    }
//   ]
//  }

json := TChilkatJsonObject.Create(Self);
json.AppendInt('homeMobileCountryCode',310);
json.AppendInt('homeMobileNetworkCode',260);
json.AppendString('radioType','gsm');
json.AppendString('carrier','T-Mobile');

aCellTowers := TChilkatJsonArray.Create(Self);
json.AppendArray2('cellTowers',aCellTowers.ControlInterface);

oCellTower := TChilkatJsonObject.Create(Self);
aCellTowers.AddObjectAt2(0,oCellTower.ControlInterface);
oCellTower.AppendInt('cellId',39627456);
oCellTower.AppendInt('locationAreaCode',40495);
oCellTower.AppendInt('mobileCountryCode',310);
oCellTower.AppendInt('mobileNetworkCode',260);
oCellTower.AppendInt('age',0);
oCellTower.AppendInt('signalStrength',-95);

aWifi := TChilkatJsonArray.Create(Self);
json.AppendArray2('wifiAccessPoints',aWifi.ControlInterface);

oPoint := TChilkatJsonObject.Create(Self);
aWifi.AddObjectAt2(0,oPoint.ControlInterface);
oPoint.AppendString('macAddress','01:23:45:67:89:AB');
oPoint.AppendInt('signalStrength',8);
oPoint.AppendInt('age',0);
oPoint.AppendInt('signalToNoiseRatio',-65);
oPoint.AppendInt('channel',8);

aWifi.AddObjectAt2(1,oPoint.ControlInterface);
oPoint.AppendString('macAddress','01:23:45:67:89:AC');
oPoint.AppendInt('signalStrength',4);
oPoint.AppendInt('age',0);

responseJson := rest.FullRequestString('POST','/geolocation/v1/geolocate',json.Emit());
if (rest.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

//  When successful, the response code is 200.
if (rest.ResponseStatusCode <> 200) then
  begin
    //  Examine the request/response to see what happened.
    Memo1.Lines.Add('response status code = ' + IntToStr(rest.ResponseStatusCode));
    Memo1.Lines.Add('response status text = ' + rest.ResponseStatusText);
    Memo1.Lines.Add('response header: ' + rest.ResponseHeader);
    Memo1.Lines.Add('response JSON: ' + responseJson);
    Memo1.Lines.Add('---');
    Memo1.Lines.Add('LastRequestStartLine: ' + rest.LastRequestStartLine);
    Memo1.Lines.Add('LastRequestHeader: ' + rest.LastRequestHeader);
    Exit;
  end;

json.EmitCompact := 0;
Memo1.Lines.Add('JSON request body: ' + json.Emit());

//  The JSON response should look like this:
//  { 
//   "location": {
//    "lat": 37.4248297,
//    "lng": -122.07346549999998
//   },
//   "accuracy": 1145.0
//  }

Memo1.Lines.Add('JSON response: ' + responseJson);

jsonResp := TChilkatJsonObject.Create(Self);
jsonResp.Load(responseJson);

jsonLoc := TChilkatJsonObject.Create(Self);
jsonResp.ObjectOf2('location',jsonLoc.ControlInterface);

//  Any JSON value can be obtained as a string..
latitude := jsonLoc.StringOf('lat');
Memo1.Lines.Add('latitude = ' + latitude);
longitude := jsonLoc.StringOf('lng');
Memo1.Lines.Add('longitude = ' + longitude);

accuracy := jsonResp.StringOf('accuracy');
Memo1.Lines.Add('accuracy = ' + accuracy);