Delphi ActiveX

DVLA Vehicle Enquiry Service

See more _Miscellaneous_ Examples

Demonstrates how to make a call to the DVLA Vehicle Enquiry API to get vehicle details of a specified vehicle. It uses the vehicle registration number as input to search and provide details of the vehicle. Delphi ActiveX

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
http: TChilkatHttp;
json: TChilkatJsonObject;
resp: TChilkatHttpResponse;
sbResponseBody: TChilkatStringBuilder;
jResp: TChilkatJsonObject;
respStatusCode: Integer;
artEndDate: WideString;
co2Emissions: Integer;
colour: WideString;
engineCapacity: Integer;
fuelType: WideString;
make: WideString;
markedForExport: Integer;
monthOfFirstRegistration: WideString;
motStatus: WideString;
registrationNumber: WideString;
revenueWeight: Integer;
taxDueDate: WideString;
taxStatus: WideString;
typeApproval: WideString;
wheelplan: WideString;
yearOfManufacture: Integer;
euroStatus: WideString;
realDrivingEmissions: WideString;
dateOfLastV5CIssued: WideString;

begin
success := 0;

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

http := TChilkatHttp.Create(Self);

// Implements the following CURL command:

// curl -X POST https://driver-vehicle-licensing.api.gov.uk/vehicle-enquiry/v1/vehicles \
//   -H "x-api-key: supplied API key" \
//   -H "Accept: application/json" \
//   -d '{"registrationNumber": "ABC1234"}'

// Use the following online tool to generate HTTP code from a CURL command
// Convert a cURL Command to HTTP Source Code

// Use this online tool to generate code from sample JSON:
// Generate Code to Create JSON

// The following JSON is sent in the request body.

// {
//   "registrationNumber": "ABC1234"
// }

json := TChilkatJsonObject.Create(Self);
json.UpdateString('registrationNumber','ABC1234');

http.SetRequestHeader('Accept','application/json');
http.SetRequestHeader('x-api-key','supplied API key');

resp := TChilkatHttpResponse.Create(Self);
success := http.HttpJson('POST','https://driver-vehicle-licensing.api.gov.uk/vehicle-enquiry/v1/vehicles',json.ControlInterface,'application/json',resp.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

sbResponseBody := TChilkatStringBuilder.Create(Self);
resp.GetBodySb(sbResponseBody.ControlInterface);
jResp := TChilkatJsonObject.Create(Self);
jResp.LoadSb(sbResponseBody.ControlInterface);
jResp.EmitCompact := 0;

Memo1.Lines.Add('Response Body:');
Memo1.Lines.Add(jResp.Emit());

respStatusCode := resp.StatusCode;
Memo1.Lines.Add('Response Status Code = ' + IntToStr(respStatusCode));
if (respStatusCode >= 400) then
  begin
    Memo1.Lines.Add('Response Header:');
    Memo1.Lines.Add(resp.Header);
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// Sample JSON response:
// (Sample code for parsing the JSON response is shown below)

// {
//   "artEndDate": "2025-02-28",
//   "co2Emissions": 135,
//   "colour": "BLUE",
//   "engineCapacity": 2494,
//   "fuelType": "PETROL",
//   "make": "ROVER",
//   "markedForExport": false,
//   "monthOfFirstRegistration": "2004-12",
//   "motStatus": "No details held by DVLA",
//   "registrationNumber": "ABC1234",
//   "revenueWeight": 1640,
//   "taxDueDate": "2007-01-01",
//   "taxStatus": "Untaxed",
//   "typeApproval": "N1",
//   "wheelplan": "NON STANDARD",
//   "yearOfManufacture": 2004,
//   "euroStatus": "EURO 6 AD",
//   "realDrivingEmissions": "1",
//   "dateOfLastV5CIssued": "2016-12-25"
// }

// Sample code for parsing the JSON response...
// Use the following online tool to generate parsing code from sample JSON:
// Generate Parsing Code from JSON

artEndDate := jResp.StringOf('artEndDate');
co2Emissions := jResp.IntOf('co2Emissions');
colour := jResp.StringOf('colour');
engineCapacity := jResp.IntOf('engineCapacity');
fuelType := jResp.StringOf('fuelType');
make := jResp.StringOf('make');
markedForExport := jResp.BoolOf('markedForExport');
monthOfFirstRegistration := jResp.StringOf('monthOfFirstRegistration');
motStatus := jResp.StringOf('motStatus');
registrationNumber := jResp.StringOf('registrationNumber');
revenueWeight := jResp.IntOf('revenueWeight');
taxDueDate := jResp.StringOf('taxDueDate');
taxStatus := jResp.StringOf('taxStatus');
typeApproval := jResp.StringOf('typeApproval');
wheelplan := jResp.StringOf('wheelplan');
yearOfManufacture := jResp.IntOf('yearOfManufacture');
euroStatus := jResp.StringOf('euroStatus');
realDrivingEmissions := jResp.StringOf('realDrivingEmissions');
dateOfLastV5CIssued := jResp.StringOf('dateOfLastV5CIssued');
end;