(Delphi ActiveX) Google Drive Multipart Upload String

Demonstrates a file upload to Google Drive where the contents of the file are contained in a string variable.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
gAuth: TChilkatAuthGoogle;
rest: TChilkatRest;
bAutoReconnect: Integer;
json: TChilkatJsonObject;
jsonResponse: WideString;

begin
// This example will upload a file to Google Drive.
success := 1;

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

gAuth := TChilkatAuthGoogle.Create(Self);
gAuth.Scope := 'https://www.googleapis.com/auth/drive';
gAuth.SubEmailAddress := 'some.user@example.com';
gAuth.ExpireNumSeconds := 3600;

// Obtain an access token as shown in one of the following examples:
// See Get Access Token using a Service Account JSON Key
// See Get Access Token using a P12 File

rest := TChilkatRest.Create(Self);

// Connect using TLS.
bAutoReconnect := 1;
success := rest.Connect('www.googleapis.com',443,1,bAutoReconnect);

// Provide the authentication credentials (i.e. the access key)
success := rest.SetAuthGoogle(gAuth.ControlInterface);

// A multipart upload to Google Drive needs a multipart/related Content-Type
success := rest.AddHeader('Content-Type','multipart/related');

// Specify each part of the request.

// The 1st part is JSON with information about the file.
rest.PartSelector := '1';
success := rest.AddHeader('Content-Type','application/json; charset=UTF-8');

json := TChilkatJsonObject.Create(Self);
success := json.AddStringAt(-1,'title','helloWorld.txt');
success := json.AddStringAt(-1,'description','A simple text file that says Hello World.');
success := json.AddStringAt(-1,'mimeType','text/plain');
success := rest.SetMultipartBodyString(json.Emit());

// The 2nd part is the file content.
// In this case, we'll upload a simple text file containing "Hello World!"
rest.PartSelector := '2';
success := rest.AddHeader('Content-Type','text/plain');
success := rest.SetMultipartBodyString('Hello World!');

// POST https://www.googleapis.com/upload/drive/v2/files
jsonResponse := rest.FullRequestMultipart('POST','/upload/drive/v2/files?uploadType=multipart');
if (rest.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

// Show the JSON response.
Memo1.Lines.Add('Response Status Code: ' + IntToStr(rest.ResponseStatusCode));
Memo1.Lines.Add('Json Response: ' + jsonResponse);
end;