Pascal (Lazarus/Delphi)

HTTPS multipart/form-data POST

See more HTTP Examples

Demonstrates how to send a multipart/form-data POST over HTTPS (using TLS). 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.Http,
  Chilkat.HttpRequest,
  Chilkat.HttpResponse;

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

procedure RunDemo;
var
  success: Boolean;
  req: THttpRequest;
  pathToFileOnDisk: string;
  fileContents: string;
  http: THttp;
  resp: THttpResponse;
  htmlStr: string;

begin
  success := False;

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

  //  This example demonstrates how to send a multipart/form-data POST that
  //  looks like this:

  //  	POST /cgi/XXX.pl HTTP/1.0
  //  	Accept: text/html
  //  	Connection: Keep-Alive
  //  	User-Agent: XXX/8.0.15
  //  	Content-type: multipart/form-data, boundary=XXXxyxy
  //  	Content-Length: 682
  //  
  //  	--XXXxyxy
  //  	content-disposition: form-data; name="UploadAgent"
  //  
  //  	InterfaceVersion1.5
  //  	--XXXxyxy
  //  	content-disposition: form-data; name="user"
  //  
  //  	userValue
  //  	--XXXxyxy
  //  	content-disposition: form-data; name="password"
  //  
  //  	passwordValue
  //  	--XXXxyxy
  //  	content-disposition: form-data; name="file"
  //  
  //  	fileValue
  //  	--XXXxyxy
  //  	content-disposition: form-data; name="data_version"
  //  
  //  	dataVersion
  //  	--XXXxyxy
  //  	content-disposition: form-data; name="content2"; filename="XXX"
  //  
  //  	THE FILE CONTENT GOES HERE...
  //  	--XXXxyxy--
  //  

  //  First, let's build the HTTP request object
  req := THttpRequest.Create;

  req.HttpVerb := 'POST';
  req.Path := '/cgi/XXX.pl';

  //  The boundary string is automatically generated and added by Chilkat.
  //  The value for the boundary string doesn't matter. (As long as it's a unique string that doesn't occur elsewhere in the request.)
  req.ContentType := 'multipart/form-data';

  //  Adding the Connection: Keep-Alive is optional.  It only makes sense if the intent is to send
  //  additional requests to the same domain (your-namespace-sb.accesscontrol.windows.net) within a reasonable time period.
  req.AddHeader('Connection','Keep-Alive');

  //  --------------------------------------------------
  //  IMPORTANT: Never set the Content-Length header.  
  //  Chilkat will automatically compute the correct Content-Length and will add it.
  //  --------------------------------------------------

  //  If a specific User-Agent header field is needed, it can be added by calling AddHeader.
  req.AddHeader('User-Agent','XXX/8.0.15');

  //  The "Accept" header, if present, tells the server what Content-Type responses will be accepted.
  //  In this case, we're telling the server that we'll only accept "text/html" responses, and therefore
  //  the server SHOULD only send a text/html response.  Technically, the Accept header is not required.
  req.AddHeader('Accept','text/html');

  //  Add the params to the request.  Given that the Content-Type is set to "multipart/form-data", when
  //  Chilkat composes the request, it will put each param in it's own MIME sub-part (i.e. in it's own
  //  part delimited by the boundary string).
  req.AddParam('UploadAgent','InterfaceVersion1.5');
  req.AddParam('user','userValue');
  req.AddParam('password','passwordValue');
  req.AddParam('file','fileValue');
  req.AddParam('data_version','dataVersion');

  //  The last param is the contents of a file.
  //  If it's a file on disk, we can add it like this:
  pathToFileOnDisk := 'c:/someDir/someFile.dat';
  success := req.AddFileForUpload('content2',pathToFileOnDisk);
  if (success = False) then
    begin
      WriteLn(req.LastErrorText);
      Exit;
    end;

  //  Alternatively, if the contents of the file are in memory, perhaps in a string
  //  variable, the file can be added like this instead.
  fileContents := 'This is the content of the file being uploaded.';
  success := req.AddStringForUpload('content2','XXX',fileContents,'utf-8');

  //  -----------------------------------------------------------
  //  IMPORTANT: To duplicate the HTTP request shown above, you'll want to choose 
  //  either AddStringForUpload or AddFileForUpload, but not both.  It's possible to upload
  //  any number of files by calling AddStringForUpload and/or AddFileForUpload any number
  //  of times, once per file to be uploaded.  This of course assumes that the receiving
  //  end is programmed to receive multiple files..
  //  ------------------------------------------------------------

  http := THttp.Create;

  //  The request is ready... now send it using HTTPS (which is port 443 by default).

  resp := THttpResponse.Create;
  success := http.HttpSReq('www.myserver.com',443,True,req,resp);
  if (success = False) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  WriteLn('HTTP response status: ' + resp.StatusCode);

  //  In this case, the response would be HTML because our Accept header
  //  told the server to only return HTML.  The HTML is available on the BodyStr
  //  property of the response object:
  htmlStr := resp.BodyStr;
  WriteLn('Received:');
  WriteLn(htmlStr);


  req.Free;
  http.Free;
  resp.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.