(Delphi ActiveX) Refresh eBay Application Access Token

This example shows how to get a new eBay REST API access token when the original is close to expiration.

Note: This example requires Chilkat v9.5.0.80 or greater. (This example was written on 21-August-2019, before v9.5.0.80 was released. If Contact Chilkat for a pre-release if the current Chilkat version is not yet at 9.5.0.80 or greater.)

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
json: TChilkatJsonObject;
success: Integer;
oauth2: TChilkatOAuth2;

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

// The previously fetched eBay access token looks like this:

// {
//   "access_token": "v^1.1#i^1# ... HwSAAA=",
//   "expires_in": 7200,
//   "refresh_token": "v^1.1#i^1# ... FXjEyODQ=",
//   "refresh_token_expires_in": 47304000,
//   "token_type": "User Access Token"
// }

json := TChilkatJsonObject.Create(Self);
success := json.LoadFile('qa_data/tokens/ebay-access-token.json');
if (success = 0) then
  begin
    Memo1.Lines.Add('Failed to load the existing ebay access token JSON.');
    Exit;
  end;

oauth2 := TChilkatOAuth2.Create(Self);

oauth2.TokenEndpoint := 'https://api.sandbox.ebay.com/identity/v1/oauth2/token';

// Replace these with actual values.
oauth2.ClientId := 'EBAY_CLIENT_ID';
oauth2.ClientSecret := 'EBAY_CLIENT_SECRET';

// Get the "refresh_token"
oauth2.RefreshToken := json.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;

// Load the access token response into the JSON object 
json.Load(oauth2.AccessTokenResponse);

// 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.
json.EmitCompact := 0;
json.WriteFile('qa_data/tokens/ebay-access-token.json');

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