Pascal (Lazarus/Delphi)

QuickBooks - Automatically Refresh Access Token with No User Interaction

See more QuickBooks Examples

Demonstrates how to automaticaly refresh an expired access token and retry the request after a 401 authorization error. 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.CkDateTime,
  Chilkat.DtObj,
  Chilkat.OAuth2,
  Chilkat.Rest,
  Chilkat.JsonObject,
  Chilkat.StringBuilder;

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

procedure RunDemo;
var
  success: Boolean;
  jsonToken: TJsonObject;
  rest: TRest;
  bAutoReconnect: Boolean;
  sbAuth: TStringBuilder;
  responseBody: string;
  oauth2: TOAuth2;
  sbJson: TStringBuilder;
  json: TJsonObject;
  dtime: TCkDateTime;
  bLocalTime: Boolean;
  dt: TDtObj;

begin
  success := False;

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

  //  Get our previously obtained OAuth2 access token, which should contain JSON like this:
  //  {
  //    "expires_in": 3600,
  //    "x_refresh_token_expires_in": 8726400,
  //    "refresh_token": "L011546037639r ... 3vR2DrbOmg0Sdagw",
  //    "access_token": "eyJlbmMiOiJBMTI4Q0 ... oETJEMbeggg",
  //    "token_type": "bearer"
  //  }

  jsonToken := TJsonObject.Create;
  success := jsonToken.LoadFile('qa_data/tokens/qb-access-token.json');

  rest := TRest.Create;

  //  Connect using TLS.
  //  A single REST object, once connected, can be used for many Quickbooks REST API calls.
  //  The auto-reconnect indicates that if the already-established HTTPS connection is closed,
  //  then it will be automatically re-established as needed.
  bAutoReconnect := True;
  success := rest.Connect('sandbox-quickbooks.api.intuit.com',443,True,bAutoReconnect);
  if (success = False) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  sbAuth := TStringBuilder.Create;
  sbAuth.Append('Bearer ');
  sbAuth.Append(jsonToken.StringOf('access_token'));
  rest.Authorization := sbAuth.GetAsString();

  rest.AddHeader('Accept','application/json');
  rest.AllowHeaderFolding := False;

  //  The company ID is 123146096291789
  //  The employee ID is 58
  responseBody := rest.FullRequestNoBody('GET','/v3/company/123146096291789/employee/58?minorversion=45');
  if (rest.LastMethodSuccess = False) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  If we get a 401 authorization error, then it's likely because the access token expired.
  //  We can automatically refresh it without interaction from the user.
  if (rest.ResponseStatusCode = 401) then
    begin

      oauth2 := TOAuth2.Create;

      oauth2.TokenEndpoint := 'https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer';

      //  Replace these with actual values.
      oauth2.ClientId := 'QUICKBOOKS-CLIENT-ID';
      oauth2.ClientSecret := 'QUICKBOOKS-CLIENT-SECRET';

      //  Get the "refresh_token"
      oauth2.RefreshToken := jsonToken.StringOf('refresh_token');

      //  Send the HTTP POST to refresh the access token..
      success := oauth2.RefreshAccessToken();
      if (success = False) then
        begin
          WriteLn(oauth2.LastErrorText);
          Exit;
        end;

      WriteLn('New access token: ' + oauth2.AccessToken);

      //  Update the JSON with the new tokens.
      jsonToken.UpdateString('access_token',oauth2.AccessToken);

      //  Save the new JSON access token response to a file.
      //  The access + refresh tokens contained in this JSON will be needed for the next refresh.
      sbJson := TStringBuilder.Create;
      jsonToken.EmitCompact := False;
      jsonToken.EmitSb(sbJson);
      sbJson.WriteFile('qa_data/tokens/qb-access-token.json','utf-8',False);

      WriteLn('OAuth2 token refreshed!');
      WriteLn('New Access Token = ' + oauth2.AccessToken);

      sbAuth.Clear();
      sbAuth.Append('Bearer ');
      sbAuth.Append(oauth2.AccessToken);
      rest.Authorization := sbAuth.GetAsString();

      //  Now retry the request with the refreshed access token...
      responseBody := rest.FullRequestNoBody('GET','/v3/company/123146096291789/employee/58?minorversion=45');
      if (rest.LastMethodSuccess = False) then
        begin
          WriteLn(rest.LastErrorText);
          Exit;
        end;

    end;

  //  We should expect a 200 response if successful.
  if (rest.ResponseStatusCode <> 200) then
    begin
      WriteLn('Request Header: ');
      WriteLn(rest.LastRequestHeader);
      WriteLn('----');
      WriteLn('Response StatusCode = ' + rest.ResponseStatusCode);
      WriteLn('Response StatusLine: ' + rest.ResponseStatusText);
      WriteLn('Response Header:');
      WriteLn(rest.ResponseHeader);
      WriteLn(responseBody);
      Exit;
    end;

  //  Load the JSON response into a JSON object for parsing.
  //  A sample JSON response is shown below.
  json := TJsonObject.Create;
  json.Load(responseBody);

  //  These will be used for parsing date/time strings..
  dtime := TCkDateTime.Create;
  bLocalTime := True;

  //  Show the JSON.   
  json.EmitCompact := False;
  WriteLn(json.Emit());

  //  Get some information from the JSON..
  WriteLn('Name: ' + json.StringOf('Employee.DisplayName'));
  WriteLn('Id: ' + json.StringOf('Employee.Id'));
  WriteLn('City: ' + json.StringOf('Employee.PrimaryAddr.City'));
  WriteLn('PostalCode: ' + json.StringOf('Employee.PrimaryAddr.PostalCode'));

  //  Load the CreateTime into a CkDateTime...
  dtime.SetFromTimestamp(json.StringOf('Employee.MetaData.CreateTime'));
  dt := TDtObj.Create;
  dtime.ToDtObj(bLocalTime,dt);

  WriteLn(dt.Month + '/' + dt.Day + '/' + dt.Year + '  ' + dt.Hour + ':' + dt.Minute);

  WriteLn('Success.');

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

  //  ------------------------------------------------------
  //  The JSON response looks like this:

  //  {
  //    "Employee": {
  //      "SSN": "XXX-XX-XXXX",
  //      "PrimaryAddr": {
  //        "Id": "116",
  //        "Line1": "45 N. Elm Street",
  //        "City": "Middlefield",
  //        "CountrySubDivisionCode": "CA",
  //        "PostalCode": "93242"
  //      },
  //      "BillableTime": false,
  //      "domain": "QBO",
  //      "sparse": false,
  //      "Id": "98",
  //      "SyncToken": "0",
  //      "MetaData": {
  //        "CreateTime": "2015-07-24T09:34:35-07:00",
  //        "LastUpdatedTime": "2015-07-24T09:34:35-07:00"
  //      },
  //      "GivenName": "Bill",
  //      "FamilyName": "Miller",
  //      "DisplayName": "Bill Miller",
  //      "PrintOnCheckName": "Bill Miller",
  //      "Active": true,
  //      "PrimaryPhone": {
  //        "FreeFormNumber": "234-525-1234"
  //      }
  //    },
  //    "time": "2015-07-24T09:35:54.805-07:00"
  //  }


  jsonToken.Free;
  rest.Free;
  sbAuth.Free;
      oauth2.Free;
      sbJson.Free;
  json.Free;
  dtime.Free;
  dt.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.