(Delphi DLL) Quickbooks OAuth2 in a Desktop App

See more QuickBooks Examples

Note: This example requires Chilkat v10.1.2 or greater.

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, OAuth2, StringBuilder;

...

procedure TForm1.Button1Click(Sender: TObject);
var
oauth2: HCkOAuth2;
url: PWideChar;
success: Boolean;
numMsWaited: Integer;
sbJson: HCkStringBuilder;
realmId: PWideChar;

begin
// To further clarify, see OAuth 2.0 Authorization Flow

// ------------------------------------------------------------------------------------------------
// IMPORTANT: You first need to define an App in the Quickbooks Developer Dashboard.
// See How to Create an App in QuickBooks Developer Dashboard
// ------------------------------------------------------------------------------------------------

// This example is for desktop applicatons (it is not for code that runs on a web server).
// You'll need to add a line (or a few lines of code) to popup a web browser that navigates to a URL.

// This is the way to initially obtain the OAuth2 access token.  Afterwards it can be 
// repeatedly refreshed without user interaction, as shown in this example: Refresh Quickbooks OAuth2 Access Token.

oauth2 := CkOAuth2_Create();

// QuickBooks OAuth2 allows for an "http://localhost:<portNumber>/" callback URL for sandbox testing,
// but not for production.

// In production, your applicaton must use your own public web server as an intermediate
// to receive and forward the redirect to localhost.
// See Using Your Web Server as an Intermediary for OAuth2 Redirect to localhost

CkOAuth2_putAppCallbackUrl(oauth2,'https://yourwebserver.com/OAuth2.php');
CkOAuth2_putListenPort(oauth2,3017);

CkOAuth2_putAuthorizationEndpoint(oauth2,'https://appcenter.intuit.com/connect/oauth2');
CkOAuth2_putTokenEndpoint(oauth2,'https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer');

// Replace these with actual values.
CkOAuth2_putClientId(oauth2,'QUICKBOOKS-CLIENT-ID');
CkOAuth2_putClientSecret(oauth2,'QUICKBOOKS-CLIENT-SECRET');
CkOAuth2_putUseBasicAuth(oauth2,True);
CkOAuth2_putCodeChallenge(oauth2,False);

// Indicate the desired access.  Possible scopes that can appear in the list are:
// com.intuit.quickbooks.accounting:  QuickBooks Online API
// com.intuit.quickbooks.payment:  QuickBooks Payments API
// openid:  OpenID Connect processing
// profile:  user's given and family names
// email:  user's email address
// phone:  user's phone number
// address:  user's physical address
CkOAuth2_putScope(oauth2,'com.intuit.quickbooks.accounting');

// Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
url := CkOAuth2__startAuth(oauth2);
if (CkOAuth2_getLastMethodSuccess(oauth2) <> True) then
  begin
    Memo1.Lines.Add(CkOAuth2__lastErrorText(oauth2));
    Exit;
  end;

Memo1.Lines.Add('url = ' + url);

// Launch the default browser on the system and navigate to the url.
// The LaunchBrowser method was added in Chilkat v10.1.2.
success := CkOAuth2_LaunchBrowser(oauth2,url);
if (success = False) then
  begin
    Memo1.Lines.Add(CkOAuth2__lastErrorText(oauth2));
    Exit;
  end;

// Wait for the user to approve or deny authorization in the browser.
numMsWaited := 0;
while (numMsWaited < 90000) and (CkOAuth2_getAuthFlowState(oauth2) < 3) do
  begin
    CkOAuth2_SleepMs(oauth2,100);
    numMsWaited := numMsWaited + 100;
  end;

// If the browser does not respond within the specified time, AuthFlowState will be:
// 
// 1: Waiting for Redirect – The OAuth2 background thread is waiting for the browser's redirect request.
// 2: Waiting for Final Response – The thread is awaiting the final access token response.
// In either case, cancel the background task initiated by StartAuth.

if (CkOAuth2_getAuthFlowState(oauth2) < 3) then
  begin
    CkOAuth2_Cancel(oauth2);
    Memo1.Lines.Add('No response from the browser!');
    Exit;
  end;

// Check AuthFlowState to determine if authorization was granted, denied, or failed:
// 
// 3: Success – OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
// 4: Access Denied – OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
// 5: Failure – OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

if (CkOAuth2_getAuthFlowState(oauth2) = 5) then
  begin
    Memo1.Lines.Add('OAuth2 failed to complete.');
    Memo1.Lines.Add(CkOAuth2__failureInfo(oauth2));
    Exit;
  end;

if (CkOAuth2_getAuthFlowState(oauth2) = 4) then
  begin
    Memo1.Lines.Add('OAuth2 authorization was denied.');
    Memo1.Lines.Add(CkOAuth2__accessTokenResponse(oauth2));
    Exit;
  end;

if (CkOAuth2_getAuthFlowState(oauth2) <> 3) then
  begin
    Memo1.Lines.Add('Unexpected AuthFlowState:' + IntToStr(CkOAuth2_getAuthFlowState(oauth2)));
    Exit;
  end;

// Save the full JSON access token response to a file.
sbJson := CkStringBuilder_Create();
CkStringBuilder_Append(sbJson,CkOAuth2__accessTokenResponse(oauth2));
CkStringBuilder_WriteFile(sbJson,'qa_data/tokens/qb-access-token.json','utf-8',False);

// The full JSON received looks like this:
// {
//   "expires_in": 3600,
//   "x_refresh_token_expires_in": 8726400,
//   "refresh_token": "L011546037639r ... 3vR2DrbOmg0Sdagw",
//   "access_token": "eyJlbmMiOiJBMTI4Q0 ... oETJEMbeggg",
//   "token_type": "bearer"
// }

Memo1.Lines.Add('OAuth2 authorization granted!');
Memo1.Lines.Add('Access Token = ' + CkOAuth2__accessToken(oauth2));

// Get the realmId if needed...
// See About the QuickBooks REST API Realm ID, also known as Company ID
realmId := CkOAuth2__getRedirectRequestParam(oauth2,'realmId');
if (CkOAuth2_getLastMethodSuccess(oauth2) = True) then
  begin
    Memo1.Lines.Add('realmId: ' + realmId);
  end
else
  begin
    Memo1.Lines.Add('No realmId was provided.');
  end;

CkOAuth2_Dispose(oauth2);
CkStringBuilder_Dispose(sbJson);

end;