Pascal (Lazarus/Delphi)

GeoOp OAuth2 Authorisation Code Grant (Public App)

See more OAuth2 Examples

Demonstrates how to get an access token for a GeoOp Third-Party Public Application using the Authorisation Code Grant flow. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.OAuth2,
  Chilkat.FileAccess;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  oauth2: TOAuth2;
  url: string;
  numMsWaited: Integer;
  fac: TFileAccess;

begin
  success := False;

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

  oauth2 := TOAuth2.Create;

  //  This should match the Site URL configured for your GeoOp (non-Server) Application, such as "http://localhost:3017/"
  oauth2.ListenPort := 3017;

  oauth2.AuthorizationEndpoint := 'https://login.geoop.com/oauth2/code';
  oauth2.TokenEndpoint := 'https://login.geoop.com/oauth2/token';

  //  Replace the client ID with an actual value.
  oauth2.ClientId := 'GEOOP-APPLICATION-ID';
  //  The ClientSecret should remain empty for a GeoOp public application
  oauth2.ClientSecret := '';

  //  We need a few special settings for GeoOp
  oauth2.Scope := 'default';
  oauth2.CodeChallenge := False;
  //  Setting LocalHost equal to "none" prevents the "redirect_uri" query param from being sent in the initial HTTP request.
  //  Note: The GeoOp Application should still have a redirect URL specified as "http://localhost:3017/", where the port
  //  number matches the ListenPort above.
  oauth2.LocalHost := 'none';

  //  Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
  url := oauth2.StartAuth();
  if (oauth2.LastMethodSuccess <> True) then
    begin
      WriteLn(oauth2.LastErrorText);
      Exit;
    end;

  //  Launch the default browser on the system and navigate to the url.
  //  The LaunchBrowser method was added in Chilkat v10.1.2.
  success := oauth2.LaunchBrowser(url);
  if (success = False) then
    begin
      WriteLn(oauth2.LastErrorText);
      Exit;
    end;

  //  Wait for the user to approve or deny authorization in the browser.
  numMsWaited := 0;
  while (numMsWaited < 90000) and (oauth2.AuthFlowState < 3) do
    begin
      oauth2.SleepMs(100);
      numMsWaited := numMsWaited + 100;
    end;

  //  If the browser does not respond within the specified time, AuthFlowState will be:
  //  
  //  1: Waiting for Redirect – The OAuth2 background thread is waiting for the browser's redirect request.
  //  2: Waiting for Final Response – The thread is awaiting the final access token response.
  //  In either case, cancel the background task initiated by StartAuth.

  if (oauth2.AuthFlowState < 3) then
    begin
      oauth2.Cancel();
      WriteLn('No response from the browser!');
      Exit;
    end;

  //  Check AuthFlowState to determine if authorization was granted, denied, or failed:
  //  
  //  3: Success – OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
  //  4: Access Denied – OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
  //  5: Failure – OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

  if (oauth2.AuthFlowState = 5) then
    begin
      WriteLn('OAuth2 failed to complete.');
      WriteLn(oauth2.FailureInfo);
      Exit;
    end;

  if (oauth2.AuthFlowState = 4) then
    begin
      WriteLn('OAuth2 authorization was denied.');
      WriteLn(oauth2.AccessTokenResponse);
      Exit;
    end;

  if (oauth2.AuthFlowState <> 3) then
    begin
      WriteLn('Unexpected AuthFlowState:' + oauth2.AuthFlowState);
      Exit;
    end;
  WriteLn('OAuth2 authorization granted!');
  WriteLn('Access Token = ' + oauth2.AccessToken);

  //  Save the entire JSON response, which includes the access token, for future calls.
  //  The JSON AccessTokenResponse looks like this:
  //  {"access_token":"e6dqdG....mzjpT04w==","token_type":"Bearer","expires_in":2592000,"owner_id":984236}

  fac := TFileAccess.Create;
  fac.WriteEntireTextFile('qa_data/tokens/geoop.json',oauth2.AccessTokenResponse,'utf-8',False);

  WriteLn('Success.');


  oauth2.Free;
  fac.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.