(Delphi ActiveX) Refresh QuickBooks OAuth2 Access Token

Demonstrates how to refresh a QuickBooks OAuth2 access token.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

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
jsonToken: TChilkatJsonObject;
success: Integer;
oauth2: TChilkatOAuth2;
sbJson: TChilkatStringBuilder;

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

// See Get QuickBooks OAuth2 Access Token 
// for sample code showing how to obtain a QuickBooks access token for desktop apps.

// This example assumes we previously obtained an OAuth2 access token for QuickBooks.

jsonToken := TChilkatJsonObject.Create(Self);
success := jsonToken.LoadFile('qa_data/tokens/qb-access-token.json');
if (success <> 1) then
  begin
    Memo1.Lines.Add('Failed to load qb-access-token.json');
    Exit;
  end;

// The access token JSON looks something like this:

// {
//   "expires_in": 3600,
//   "x_refresh_token_expires_in": 8726400,
//   "refresh_token": "L011546037639r ... 3vR2DrbOmg0Sdagw",
//   "access_token": "eyJlbmMiOiJBMTI4Q0 ... oETJEMbeggg",
//   "token_type": "bearer"
// }

oauth2 := TChilkatOAuth2.Create(Self);

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 <> 1) then
  begin
    Memo1.Lines.Add(oauth2.LastErrorText);
    Exit;
  end;

// The response contains a new access token, but we must keep
// our existing refresh token for when we need to refresh again in the future.
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 := TChilkatStringBuilder.Create(Self);
jsonToken.EmitCompact := 0;

jsonToken.EmitSb(sbJson.ControlInterface);
sbJson.WriteFile('qa_data/tokens/qb-access-token.json','utf-8',0);

Memo1.Lines.Add('OAuth2 token refreshed!');
Memo1.Lines.Add('New Access Token = ' + oauth2.AccessToken);
end;