(Delphi ActiveX) Parse Multipart Binary Http Response

This example demonstrates how to parse an HTTP response that is multipart and contains a binary file, such as a .zip or .pdf.

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;
http: TChilkatHttp;
req: TChilkatHttpRequest;
resp: IChilkatHttpResponse;
respBody: TChilkatBinData;
mime: TChilkatMime;
numParts: Integer;
part0: IChilkatMime;
xmlStr: WideString;
part1: IChilkatMime;
zipData: TChilkatBinData;

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

http := TChilkatHttp.Create(Self);

req := TChilkatHttpRequest.Create(Self);

// ...
// Insert code here to construct some kind of HTTP request.
// this example is to show how to parse a particular kind of response.
// ...
// ...

// Send the request (whatever it may be in your case) to get the HTTP response object.
resp := http.SynchronousRequest('www.somedomain.com',443,1,req.ControlInterface);
if (http.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// Get the response body (which is expected to be binary)
respBody := TChilkatBinData.Create(Self);
resp.GetBodyBd(respBody.ControlInterface);

// For this example, the response body contains something like this:

// ------=_Part_21302_2029949381.1547401515443
// Content-Type: application/xop+xml; charset=UTF-8; type="text/xml"
// Content-Transfer-Encoding: 8bit
// Content-ID: <rootpart@ws.jboss.org>
// 
// <env:Envelope xmlns:env='http://schemas.xmlsoap.org/soap/envelope/'><env:Header></env:Header><env:Body>...</env:Body></env:Envelope>
// ------=_Part_21302_2029949381.1547401515443
// Content-Type: application/octet-stream
// Content-Transfer-Encoding: binary
// Content-Id: <fileArchivio-7d302908-4d64-43d3-bf4e-79ce806d43b3@ws.jboss.org>
// 
// BINARY_CONTENT_HERE...
// 
// ------=_Part_21302_2029949381.1547401515443--
// 

// Load it into a Chilkat MIME object.
mime := TChilkatMime.Create(Self);
success := mime.LoadMimeBd(respBody.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

numParts := mime.NumParts;
if (numParts < 2) then
  begin
    Memo1.Lines.Add('Expected multipart MIME with at least 2 sub-parts.');
    Exit;
  end;

// Get the 1st sub-part, which is the XML.
part0 := mime.GetPart(0);
// Should be OK because we checked NumParts above..
xmlStr := part0.GetBodyDecoded();
Memo1.Lines.Add(xmlStr);
Memo1.Lines.Add('----');

// Save the 2nd part to a file.  (It is a .zip file in our test case..)
part1 := mime.GetPart(1);
success := part1.SaveBody('qa_output/attachedZip.zip');

// Alternatively, we could extract the binary data to a BinData and use elsewhere..
zipData := TChilkatBinData.Create(Self);
success := part1.GetBodyBd(zipData.ControlInterface);
success := zipData.WriteFile('qa_output/attachedZip_again.zip');

Memo1.Lines.Add('OK.');
end;