Delphi DLL

Get Access Token for Google Tasks using Service Account JSON Key

See more Google Tasks Examples

Demonstrates how to get an access token for the Google Tasks API using a Service Account JSON key. Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, FileAccess, AuthGoogle, Socket;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
fac: HCkFileAccess;
jsonKey: PWideChar;
gAuth: HCkAuthGoogle;
tlsSock: HCkSocket;

begin
success := False;

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

// First load the JSON key into a string.
fac := CkFileAccess_Create();
jsonKey := CkFileAccess__readEntireTextFile(fac,'qa_data/googleSvcAccountKeys/ChilkatCloud-48f7737c7505.json','utf-8');
if (CkFileAccess_getLastMethodSuccess(fac) <> True) then
  begin
    Memo1.Lines.Add(CkFileAccess__lastErrorText(fac));
    Exit;
  end;

// A JSON private key should look like this:

// {
//   "type": "service_account",
//   "project_id": "chilkatcloud",
//   "private_key_id": "48f7737c7505bb88eee6a20d09993e10605d466e",
//   "private_key": "-----BEGIN PRIVATE KEY----- ... -----END PRIVATE KEY-----\n",
//   "client_email": "pip-564@chilkatcloud.iam.gserviceaccount.com",
//   "client_id": "109982228323456925225",
//   "auth_uri": "https://accounts.google.com/o/oauth2/auth",
//   "token_uri": "https://oauth2.googleapis.com/token",
//   "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
//   "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/pip-564%40chilkatcloud.iam.gserviceaccount.com"
// }

gAuth := CkAuthGoogle_Create();
CkAuthGoogle_putJsonKey(gAuth,jsonKey);

// Choose the scope for read/write access.
CkAuthGoogle_putScope(gAuth,'https://www.googleapis.com/auth/tasks');

// Request an access token that is valid for this many seconds.
CkAuthGoogle_putExpireNumSeconds(gAuth,3600);

CkAuthGoogle_putSubEmailAddress(gAuth,'');

// Connect to www.googleapis.com using TLS
tlsSock := CkSocket_Create();
success := CkSocket_Connect(tlsSock,'www.googleapis.com',443,True,5000);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(tlsSock));
    Exit;
  end;

// Send the request to obtain the access token.
success := CkAuthGoogle_ObtainAccessToken(gAuth,tlsSock);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkAuthGoogle__lastErrorText(gAuth));
    Exit;
  end;

// Examine the access token:
Memo1.Lines.Add('Access Token: ' + CkAuthGoogle__accessToken(gAuth));

// Save our access token to a file.
success := CkFileAccess_WriteEntireTextFile(fac,'qa_data/tokens/googleTasks.txt',CkAuthGoogle__accessToken(gAuth),'utf-8',False);

CkFileAccess_Dispose(fac);
CkAuthGoogle_Dispose(gAuth);
CkSocket_Dispose(tlsSock);

end;