(Delphi ActiveX) Yahoo Mail OAuth2 Access Token for Desktop App

See more Yahoo Mail Examples

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

For more information, see https://developer.yahoo.com/oauth2/guide/

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
oauth2: TChilkatOAuth2;
url: WideString;
success: Integer;
numMsWaited: Integer;
sbJson: TChilkatStringBuilder;

begin
// First, you must define your app in Yahoo Developer (https://developer.yahoo.com/apps/) like this:

// 

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

oauth2 := TChilkatOAuth2.Create(Self);

// 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
oauth2.AppCallbackUrl := 'https://yourwebserver.com/oauth_redirect';
oauth2.ListenPort := 3017;

oauth2.AuthorizationEndpoint := 'https://api.login.yahoo.com/oauth2/request_auth';
oauth2.TokenEndpoint := 'https://api.login.yahoo.com/oauth2/get_token';

// Replace these with actual values.
oauth2.ClientId := 'CLIENT_ID';
oauth2.ClientSecret := 'CLIENT_SECRET';

// Do not send the "scope" query param for Yahoo OAuth2.
oauth2.UncommonOptions := 'NO_OAUTH2_SCOPE';

// Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
url := oauth2.StartAuth();
if (oauth2.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(oauth2.LastErrorText);
    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 := oauth2.LaunchBrowser(url);
if (success = 0) then
  begin
    Memo1.Lines.Add(oauth2.LastErrorText);
    Exit;
  end;

// Wait for the user to approve or deny authorization in the browser.
numMsWaited := 0;
while (numMsWaited < 90000) and (oauth2.AuthFlowState < 3) do
  begin
    oauth2.SleepMs(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 (oauth2.AuthFlowState < 3) then
  begin
    oauth2.Cancel();
    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 (oauth2.AuthFlowState = 5) then
  begin
    Memo1.Lines.Add('OAuth2 failed to complete.');
    Memo1.Lines.Add(oauth2.FailureInfo);
    Exit;
  end;

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

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

// Save the full JSON access token response to a file.
sbJson := TChilkatStringBuilder.Create(Self);
sbJson.Append(oauth2.AccessTokenResponse);
sbJson.WriteFile('qa_data/tokens/yahooMail.json','utf-8',0);

// The saved JSON response looks like this:

// {
//   "access_token": "kCVQdnOdul...LHucA--",
//   "refresh_token": "AIenVXETSo0jklFBVkPS8vVm8E.Ej9ToRG.xDbDYmZ65WIs5t6CZhDrD",
//   "expires_in": 3600,
//   "token_type": "bearer",
//   "xoauth_yahoo_guid": "HGDQCVF5JB4YDOWHITQJFBHCWA"
// }

Memo1.Lines.Add('OAuth2 authorization granted!');
Memo1.Lines.Add('Access Token: ' + oauth2.AccessToken);
end;