(Delphi ActiveX) Yahoo Mail Refresh OAuth2 Access Token

See more Yahoo Mail Examples

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
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.

// It is assumed we previously obtained an OAuth2 access token.
// This example loads the JSON access token file 
// saved by this example: Get Yahoo Mail OAuth2 Access Token

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

// The access token JSON looks like this:

// {
//   "access_token": "kCVQdnOdul...LHucA--",
//   "refresh_token": "AIenVWETSo0jklFBVkPS8vVm8E.Dj9ToRG.xDbDYmZ55WIs5t6CZhDkD",
//   "expires_in": 3600,
//   "token_type": "bearer",
//   "xoauth_yahoo_guid": "HGDQCVF6JB4YDOWHITPJFBHCWA"
// }

oauth2 := TChilkatOAuth2.Create(Self);

// See Step 5 at https://developer.yahoo.com/oauth2/guide/flows_authcode/
oauth2.TokenEndpoint := 'https://api.login.yahoo.com/oauth2/get_token';

// Replace these with actual values.
oauth2.ClientId := 'CLIENT_ID';
oauth2.ClientSecret := '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.
sbJson := TChilkatStringBuilder.Create(Self);
jsonToken.EmitCompact := 0;
jsonToken.EmitSb(sbJson.ControlInterface);
sbJson.WriteFile('qa_data/tokens/yahooMail.json','utf-8',0);

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