(Delphi DLL) List all Pages of Files in Google Drive

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

See Google Drive Files list for more optional HTTP parameters.

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, AuthGoogle, JsonObject, Rest;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
gAuth: HCkAuthGoogle;
rest: HCkRest;
bAutoReconnect: Boolean;
json: HCkJsonObject;
i: Integer;
numFiles: Integer;
jsonResponse: PWideChar;
pageNumber: Integer;
pageToken: PWideChar;
bContinueLoop: Boolean;
bHasMorePages: Boolean;

begin
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 := CkAuthGoogle_Create();
CkAuthGoogle_putAccessToken(gAuth,'GOOGLE-DRIVE-ACCESS-TOKEN');

rest := CkRest_Create();

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

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

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

json := CkJsonObject_Create();

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

pageNumber := 1;

bContinueLoop := CkRest_getLastMethodSuccess(rest) and (CkRest_getResponseStatusCode(rest) = 200);

while bContinueLoop = True do
  begin

    Memo1.Lines.Add('---- Page ' + IntToStr(pageNumber) + ' ----');

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

    // See the sample JSON response at the bottom of this example.
    numFiles := CkJsonObject_SizeOfArray(json,'files');
    i := 0;
    while i < numFiles do
      begin
        CkJsonObject_putI(json,i);
        Memo1.Lines.Add('name: ' + CkJsonObject__stringOf(json,'files[i].name'));
        Memo1.Lines.Add('id: ' + CkJsonObject__stringOf(json,'files[i].id'));
        Memo1.Lines.Add('mimeType: ' + CkJsonObject__stringOf(json,'files[i].mimeType'));
        Memo1.Lines.Add('-');
        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 := CkJsonObject__stringOf(json,'nextPageToken');
    bContinueLoop := False;
    bHasMorePages := CkJsonObject_getLastMethodSuccess(json);
    if (bHasMorePages = True) then
      begin
        CkRest_ClearAllQueryParams(rest);
        CkRest_AddQueryParam(rest,'pageSize','5');
        CkRest_AddQueryParam(rest,'pageToken',pageToken);
        jsonResponse := CkRest__fullRequestNoBody(rest,'GET','/drive/v3/files');
        bContinueLoop := CkRest_getLastMethodSuccess(rest) and (CkRest_getResponseStatusCode(rest) = 200);
        pageNumber := pageNumber + 1;
      end;

  end;

if (CkRest_getLastMethodSuccess(rest) <> True) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

// A successful response will have a status code equal to 200.
if (CkRest_getResponseStatusCode(rest) <> 200) then
  begin
    Memo1.Lines.Add('response status code = ' + IntToStr(CkRest_getResponseStatusCode(rest)));
    Memo1.Lines.Add('response status text = ' + CkRest__responseStatusText(rest));
    Memo1.Lines.Add('response header: ' + CkRest__responseHeader(rest));
    Memo1.Lines.Add('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"
//    }
//  ]
// }

CkAuthGoogle_Dispose(gAuth);
CkRest_Dispose(rest);
CkJsonObject_Dispose(json);

end;