Delphi DLL

HTTPS multipart/form-data POST

See more HTTP Examples

Demonstrates how to send a multipart/form-data POST over HTTPS (using TLS). Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
req: HCkHttpRequest;
pathToFileOnDisk: PWideChar;
fileContents: PWideChar;
http: HCkHttp;
resp: HCkHttpResponse;
htmlStr: PWideChar;

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 := CkHttpRequest_Create();

CkHttpRequest_putHttpVerb(req,'POST');
CkHttpRequest_putPath(req,'/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.)
CkHttpRequest_putContentType(req,'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.
CkHttpRequest_AddHeader(req,'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.
CkHttpRequest_AddHeader(req,'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.
CkHttpRequest_AddHeader(req,'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).
CkHttpRequest_AddParam(req,'UploadAgent','InterfaceVersion1.5');
CkHttpRequest_AddParam(req,'user','userValue');
CkHttpRequest_AddParam(req,'password','passwordValue');
CkHttpRequest_AddParam(req,'file','fileValue');
CkHttpRequest_AddParam(req,'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 := CkHttpRequest_AddFileForUpload(req,'content2',pathToFileOnDisk);
if (success = False) then
  begin
    Memo1.Lines.Add(CkHttpRequest__lastErrorText(req));
    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 := CkHttpRequest_AddStringForUpload(req,'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 := CkHttp_Create();

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

resp := CkHttpResponse_Create();
success := CkHttp_HttpSReq(http,'www.myserver.com',443,True,req,resp);
if (success = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

Memo1.Lines.Add('HTTP response status: ' + IntToStr(CkHttpResponse_getStatusCode(resp)));

// 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 := CkHttpResponse__bodyStr(resp);
Memo1.Lines.Add('Received:');
Memo1.Lines.Add(htmlStr);

CkHttpRequest_Dispose(req);
CkHttp_Dispose(http);
CkHttpResponse_Dispose(resp);

end;