(Delphi DLL) 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 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, JsonObject, OAuth2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
json: HCkJsonObject;
success: Boolean;
oauth2: HCkOAuth2;

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 := CkJsonObject_Create();
success := CkJsonObject_LoadFile(json,'qa_data/tokens/ebay-access-token.json');
if (success = False) then
  begin
    Memo1.Lines.Add('Failed to load the existing ebay access token JSON.');
    Exit;
  end;

oauth2 := CkOAuth2_Create();

CkOAuth2_putTokenEndpoint(oauth2,'https://api.sandbox.ebay.com/identity/v1/oauth2/token');

// Replace these with actual values.
CkOAuth2_putClientId(oauth2,'EBAY_CLIENT_ID');
CkOAuth2_putClientSecret(oauth2,'EBAY_CLIENT_SECRET');

// Get the "refresh_token"
CkOAuth2_putRefreshToken(oauth2,CkJsonObject__stringOf(json,'refresh_token'));

// Send the HTTP POST to refresh the access token..
success := CkOAuth2_RefreshAccessToken(oauth2);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkOAuth2__lastErrorText(oauth2));
    Exit;
  end;

// Load the access token response into the JSON object 
CkJsonObject_Load(json,CkOAuth2__accessTokenResponse(oauth2));

// 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.
CkJsonObject_putEmitCompact(json,False);
CkJsonObject_WriteFile(json,'qa_data/tokens/ebay-access-token.json');

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

CkJsonObject_Dispose(json);
CkOAuth2_Dispose(oauth2);

end;