Pascal (Lazarus/Delphi)

List all Pages of Files in Google Drive

See more Google Drive Examples

Demonstrates how iterate over pages to list files in Google Drive.

See Google Drive Files list for more optional HTTP parameters.

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.AuthGoogle,
  Chilkat.JsonObject,
  Chilkat.Rest;

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

procedure RunDemo;
var
  success: Boolean;
  gAuth: TAuthGoogle;
  rest: TRest;
  bAutoReconnect: Boolean;
  json: TJsonObject;
  i: Integer;
  numFiles: Integer;
  jsonResponse: string;
  pageNumber: Integer;
  pageToken: string;
  bContinueLoop: Boolean;
  bHasMorePages: Boolean;

begin
  success := False;

  success := True;

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

  //  This example uses a previously obtained access token having permission for the 
  //  Google Drive scope.

  gAuth := TAuthGoogle.Create;
  gAuth.AccessToken := 'GOOGLE-DRIVE-ACCESS-TOKEN';

  rest := TRest.Create;

  //  Connect using TLS.
  bAutoReconnect := True;
  success := rest.Connect('www.googleapis.com',443,True,bAutoReconnect);

  //  Provide the authentication credentials (i.e. the access token)
  rest.SetAuthGoogle(gAuth);

  //  Get 5 results per page for testing.  (The default page size is 100, with a max of 1000.
  rest.AddQueryParam('pageSize','5');

  json := TJsonObject.Create;

  //  Send the request for the 1st page.
  jsonResponse := rest.FullRequestNoBody('GET','/drive/v3/files');

  pageNumber := 1;

  bContinueLoop := rest.LastMethodSuccess and (rest.ResponseStatusCode = 200);

  while bContinueLoop = True do
    begin

      WriteLn('---- Page ' + pageNumber + ' ----');

      //  Iterate over each file in the response and show the name, id, and mimeType.
      json.Load(jsonResponse);

      //  See the sample JSON response at the bottom of this example.
      numFiles := json.SizeOfArray('files');
      i := 0;
      while i < numFiles do
        begin
          json.I := i;
          WriteLn('name: ' + json.StringOf('files[i].name'));
          WriteLn('id: ' + json.StringOf('files[i].id'));
          WriteLn('mimeType: ' + json.StringOf('files[i].mimeType'));
          WriteLn('-');
          i := i + 1;
        end;

      //  Get the next page of files.
      //  If the "nextPageToken" is present in the JSON response, then use it in the "pageToken" parameter
      //  for the next request.   If no "nextPageToken" was present, then this was the last page of files.
      pageToken := json.StringOf('nextPageToken');
      bContinueLoop := False;
      bHasMorePages := json.LastMethodSuccess;
      if (bHasMorePages = True) then
        begin
          rest.ClearAllQueryParams();
          rest.AddQueryParam('pageSize','5');
          rest.AddQueryParam('pageToken',pageToken);
          jsonResponse := rest.FullRequestNoBody('GET','/drive/v3/files');
          bContinueLoop := rest.LastMethodSuccess and (rest.ResponseStatusCode = 200);
          pageNumber := pageNumber + 1;
        end;

    end;

  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  A successful response will have a status code equal to 200.
  if (rest.ResponseStatusCode <> 200) then
    begin
      WriteLn('response status code = ' + rest.ResponseStatusCode);
      WriteLn('response status text = ' + rest.ResponseStatusText);
      WriteLn('response header: ' + rest.ResponseHeader);
      WriteLn('response JSON: ' + jsonResponse);
      Exit;
    end;

  //  A successful JSON response looks like this:
  //  {
  //   "kind": "drive#fileList",
  //   "files": [
  //     {
  //       "kind": "drive#file",
  //       "id": "0B53Q6OSTWYolenpjTEU4ekJlQUU",
  //       "name": "test",
  //       "mimeType": "application/vnd.google-apps.folder"
  //     },
  //     {
  //       "kind": "drive#file",
  //       "id": "0B53Q6OSTWYolRm4ycjZtdXhRaEE",
  //       "name": "starfish4.jpg",
  //       "mimeType": "image/jpeg"
  //     },
  //     {
  //       "kind": "drive#file",
  //       "id": "0B53Q6OSTWYolMWt2VzN0Qlo1UjA",
  //       "name": "hamlet2.xml",
  //       "mimeType": "text/xml"
  //     },
  //  ...
  //     {
  //       "kind": "drive#file",
  //       "id": "0B53Q6OSTWYolc3RhcnRlcl9maWxlX2Rhc2hlclYw",
  //       "name": "Getting started",
  //       "mimeType": "application/pdf"
  //     }
  //   ]
  //  }


  gAuth.Free;
  rest.Free;
  json.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.