Pascal (Lazarus/Delphi)

Box.com Streaming Upload File

See more Box Examples

Demonstrates how to upload a file to box.com, streaming the file directly from the filesystem.

Note: This example requires a fix that is included in Chilkat v9.5.0.70 and above.

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.Rest,
  Chilkat.JsonObject,
  Chilkat.Stream;

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

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  oauth2: TOAuth2;
  bAutoReconnect: Boolean;
  jsonAttr: TJsonObject;
  fileStream: TStream;
  responseBody: string;

begin
  success := False;

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

  rest := TRest.Create;

  //    Provide a previously obtained OAuth2 access token.
  oauth2 := TOAuth2.Create;
  oauth2.AccessToken := 'BOX_ACCESS_TOKEN';
  rest.SetAuthOAuth2(oauth2);

  //  First, make the initial connection.
  //  A single REST object, once connected, can be used for many Box REST API calls.
  //  The auto-reconnect indicates that if the already-established HTTPS connection is closed,
  //  then it will be automatically re-established as needed.
  bAutoReconnect := True;

  //  ----------------------------------------------------------------------
  //  IMPORTANT: Note that the domain is "upload.box.com", not "api.box.com"
  //  ----------------------------------------------------------------------
  success := rest.Connect('upload.box.com',443,True,bAutoReconnect);
  if (success <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  The request body uses the "multipart/form-data" format to transmit two "parts". 
  //  The first part is called "attributes" and contains a JSON object with information about the file, including the name of the file 
  //  and the ID of the parent folder. The second part contains the contents of the file. 
  //  (Note that the name of the second "part" is ignored.)

  rest.AddHeader('Content-Type','multipart/form-data');

  //  Provide the content for each part of the request...

  //  First the JSON attributes.  Use "0" for the root folder.
  //    {"name":"hedgehogs.jpg", "parent":{"id":"0"}}
  jsonAttr := TJsonObject.Create;
  jsonAttr.UpdateString('name','hedgehogs.jpg');
  jsonAttr.UpdateString('parent.id','0');

  rest.PartSelector := '1';
  rest.AddHeader('Content-Disposition','form-data; name="attributes"; ');
  rest.SetMultipartBodyString(jsonAttr.Emit());

  //  The upload will stream directly from a file.
  rest.PartSelector := '2';
  rest.AddHeader('Content-Disposition','form-data; name="file"; filename="hedgehogs.jpg"');
  //  "application/octet-stream" can be safely used for any type file..
  rest.AddHeader('Content-Type','application/octet-stream');

  //  IMPORTANT: This example requires Chilkat v9.5.0.70 or later, for a fix that was made in
  //  multipart/streaming uploads. 
  fileStream := TStream.Create;
  fileStream.SourceFile := 'qa_data/jpg/hedgehogs.jpg';
  rest.SetMultipartBodyStream(fileStream);

  //  Restore the PartSelector to "0" (for safety, in case something else sends another request on this object)
  rest.PartSelector := '0';

  //  Send the multipart/form-data request, which uploads the file by streaming directly from the filesystem.
  responseBody := rest.FullRequestMultipart('POST','/api/2.0/files/content');
  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  A 201 is received for a successful upload
  if (rest.ResponseStatusCode <> 201) then
    begin
      WriteLn('Box.com upload failed.');
      WriteLn('Request header:');
      WriteLn(rest.LastRequestHeader);
      WriteLn('---');
      WriteLn('Response status code = ' + rest.ResponseStatusCode);
      WriteLn('Response body:');
      WriteLn(responseBody);
      Exit;
    end;

  WriteLn('File uploaded.');


  rest.Free;
  oauth2.Free;
  jsonAttr.Free;
  fileStream.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.