(Delphi DLL) GeoOp Exchange Refresh Token for New Access Token

Demonstrates how to use the /oauth2/token endpoint to exchange it for a new access token once the current access token has expired.

Note: This example requires Chilkat v9.5.0.65 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, Rest, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
jsonToken: HCkJsonObject;
success: Boolean;
rest: HCkRest;
bAutoReconnect: Boolean;
responseBody: PWideChar;
json: HCkJsonObject;

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

// This example also assumes that OAuth2 access and refresh tokens were previously fetched.
// and saved in a JSON file.  

// First get our previously obtained refresh token.
// { .... "refresh_token":"e6dqdG....mzjpT04w==", .... }
jsonToken := CkJsonObject_Create();
success := CkJsonObject_LoadFile(jsonToken,'qa_data/tokens/geoop.json');

rest := CkRest_Create();

// Connect to GeoOp...
bAutoReconnect := True;
success := CkRest_Connect(rest,'login.geoop.com',443,True,bAutoReconnect);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

// Set the X-Version header.
CkRest_AddHeader(rest,'X-Version','1.0');

// Provide the required form params to get the new access token
Memo1.Lines.Add('refresh_token = ' + CkJsonObject__stringOf(jsonToken,'refresh_token'));
CkRest_AddQueryParam(rest,'refresh_token',CkJsonObject__stringOf(jsonToken,'refresh_token'));
CkRest_AddQueryParam(rest,'grant_type','refresh_token');
CkRest_AddQueryParam(rest,'client_id','GEOOP-CLIENT-ID');
CkRest_AddQueryParam(rest,'client_secret','GEOOP-CLIENT-SECRET');

responseBody := CkRest__fullRequestFormUrlEncoded(rest,'POST','/oauth2/token');
if (CkRest_getLastMethodSuccess(rest) <> True) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

// If the response status code did not indicate success, then see what happened..
if (CkRest_getResponseStatusCode(rest) <> 200) then
  begin
    Memo1.Lines.Add('Request Header: ');
    Memo1.Lines.Add(CkRest__lastRequestHeader(rest));
    Memo1.Lines.Add('----');
    Memo1.Lines.Add('Response StatusCode = ' + IntToStr(CkRest_getResponseStatusCode(rest)));
    Memo1.Lines.Add('Response StatusLine: ' + CkRest__responseStatusText(rest));
    Memo1.Lines.Add('Response Header:');
    Memo1.Lines.Add(CkRest__responseHeader(rest));
    Memo1.Lines.Add(responseBody);
    Exit;
  end;

json := CkJsonObject_Create();
CkJsonObject_putEmitCompact(json,False);
CkJsonObject_Load(json,responseBody);

// Show the full JSON response.  It should contain the new access token...
Memo1.Lines.Add(CkJsonObject__emit(json));

CkJsonObject_Dispose(jsonToken);
CkRest_Dispose(rest);
CkJsonObject_Dispose(json);

end;