(Delphi ActiveX) Upload File from String

Uploads a text file where the contents of the file are contained in a string variable.

See Google Drive Files: create for more details.

Also See Google Drive Multipart Upload for more details.

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;
fileContents: WideString;
jsonResponse: WideString;

begin
success := 1;

// 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 := TChilkatAuthGoogle.Create(Self);
gAuth.AccessToken := 'GOOGLE-DRIVE-ACCESS-TOKEN';

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 token)
rest.SetAuthGoogle(gAuth.ControlInterface);

// A multipart upload to Google Drive needs a multipart/related Content-Type
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';
rest.AddHeader('Content-Type','application/json; charset=UTF-8');

json := TChilkatJsonObject.Create(Self);
json.AppendString('name','helloWorld.txt');
json.AppendString('description','A simple text file that says Hello World.');
json.AppendString('mimeType','text/plain');
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';
rest.AddHeader('Content-Type','text/plain');

fileContents := 'Hello World!';
rest.SetMultipartBodyString(fileContents);

jsonResponse := rest.FullRequestMultipart('POST','/upload/drive/v3/files?uploadType=multipart');
if (rest.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

// A successful response will have a status code equal to 200.
if (rest.ResponseStatusCode <> 200) then
  begin
    Memo1.Lines.Add('response status code = ' + IntToStr(rest.ResponseStatusCode));
    Memo1.Lines.Add('response status text = ' + rest.ResponseStatusText);
    Memo1.Lines.Add('response header: ' + rest.ResponseHeader);
    Memo1.Lines.Add('response JSON: ' + jsonResponse);
    Exit;
  end;

// Show the JSON response.
json.Load(jsonResponse);

// Show the full JSON response.
json.EmitCompact := 0;
Memo1.Lines.Add(json.Emit());

// A successful response looks like this:
// {
//   "kind": "drive#file",
//   "id": "0B53Q6OSTWYoldmJ0Z3ZqT2x5MFk",
//   "name": "Untitled",
//   "mimeType": "text/plain"
// }

// Get the fileId:
Memo1.Lines.Add('fileId: ' + json.StringOf('id'));
end;