Pascal (Lazarus/Delphi)

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. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Http,
  Chilkat.StringBuilder,
  Chilkat.HttpResponse,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  http: THttp;
  json: TJsonObject;
  resp: THttpResponse;
  sbResponseBody: TStringBuilder;
  jResp: TJsonObject;
  respStatusCode: Integer;
  artEndDate: string;
  co2Emissions: Integer;
  colour: string;
  engineCapacity: Integer;
  fuelType: string;
  make: string;
  markedForExport: Boolean;
  monthOfFirstRegistration: string;
  motStatus: string;
  registrationNumber: string;
  revenueWeight: Integer;
  taxDueDate: string;
  taxStatus: string;
  typeApproval: string;
  wheelplan: string;
  yearOfManufacture: Integer;
  euroStatus: string;
  realDrivingEmissions: string;
  dateOfLastV5CIssued: string;

begin
  success := False;

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

  http := THttp.Create;

  //  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 := TJsonObject.Create;
  json.UpdateString('registrationNumber','ABC1234');

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

  resp := THttpResponse.Create;
  success := http.HttpJson('POST','https://driver-vehicle-licensing.api.gov.uk/vehicle-enquiry/v1/vehicles',json,'application/json',resp);
  if (success = False) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  sbResponseBody := TStringBuilder.Create;
  resp.GetBodySb(sbResponseBody);
  jResp := TJsonObject.Create;
  jResp.LoadSb(sbResponseBody);
  jResp.EmitCompact := False;

  WriteLn('Response Body:');
  WriteLn(jResp.Emit());

  respStatusCode := resp.StatusCode;
  WriteLn('Response Status Code = ' + respStatusCode);
  if (respStatusCode >= 400) then
    begin
      WriteLn('Response Header:');
      WriteLn(resp.Header);
      WriteLn('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');


  http.Free;
  json.Free;
  resp.Free;
  sbResponseBody.Free;
  jResp.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.