Dart Requires Chilkat v11.0.0+

How to Access Parts of a multipart/related HTTP Response

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Demonstrates how to access the parts of a multipart/related response. This example sends a ficticious multipart/related request, and handles a ficticious multipart/related response.

We send the following multipart/related request:

Content-Type: multipart/related; start-info="text/xml"; type="application/xop+xml"; boundary="----=_Part_0_1744155.1118953559416"
Content-Length: 3453
SOAPAction: "some-SOAP-action"

------=_Part_1_4558657.1118953559446
Content-Type: application/xop+xml; type="text/xml"; charset=utf-8

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Body>
    <Detail xmlns="http://example.org/mtom/data">
      <image>
        <xop:Include xmlns:xop="http://www.w3.org/2004/08/xop/include" href="cid:5aeaa450-17f0-4484-b845-a8480c363444@example.org" />
      </image>
    </Detail>
  </soap:Body>
</soap:Envelope>

------=_Part_1_4558657.1118953559446
Content-Type: image/jpeg
Content-ID: <5aeaa450-17f0-4484-b845-a8480c363444@example.org>


... binary data ...

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  final http = CkHttp();

  final soapXml = CkXml();

  // Build the following SOAP XML

  // <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  //   <soap:Body>
  //     <Detail xmlns="http://example.org/mtom/data">
  //       <image>
  //         <xop:Include xmlns:xop="http://www.w3.org/2004/08/xop/include" href="cid:5aeaa450-17f0-4484-b845-a8480c363444@example.org" />
  //       </image>
  //     </Detail>
  //   </soap:Body>
  // </soap:Envelope>

  soapXml.tag = 'soap:Envelope';
  soapXml.addAttribute('xmlns:soap', 'http://schemas.xmlsoap.org/soap/envelope/');
  soapXml.updateAttrAt('soap:Body|Detail', true, 'xmlns', 'http://example.org/mtom/data');
  soapXml.updateAttrAt('soap:Body|Detail|image|xop:Include', true, 'xmlns:xop', 'http://www.w3.org/2004/08/xop/include');
  soapXml.updateAttrAt('soap:Body|Detail|image|xop:Include', true, 'href', 'cid:5aeaa450-17f0-4484-b845-a8480c363444@example.org');

  soapXml.emitXmlDecl = false;
  final xmlBody = soapXml.getXml();
  print(xmlBody);

  final req = CkHttpRequest();
  req.httpVerb = 'POST';
  req.path = '/something/someTarget';

  req.contentType = 'multipart/related; start-info="text/xml"; type="application/xop+xml"';
  req.addHeader('SOAPAction', 'some-SOAP-action');

  req.addStringForUpload2('', '', xmlBody, 'utf-8', 'application/xop+xml; type="text/xml"; charset=utf-8');

  // The bytes will be sent as binary (not base64 encoded).
  req.addFileForUpload2('', 'qa_data/jpg/starfish.jpg', 'image/jpeg');

  // The JPEG data is the 2nd sub-part, and therefore is at index 1 (the first sub-part is at index 0)
  req.addSubHeader(1, 'Content-ID', '<5aeaa450-17f0-4484-b845-a8480c363444@example.org>');

  http.followRedirects = true;

  final useTls = true;
  final resp = CkHttpResponse();
  try {
    http.httpSReq('www.example.org', 443, useTls, req, resp);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Imagine the HTTP response is multipart related and is something like this:

  // HTTP/1.1 200 OK
  // Cache-Control: no-cache, no-store
  // Pragma: no-cache
  // Transfer-Encoding: chunked
  // Content-Type: multipart/related; boundary=------------080001080500020607080905
  // Expires: -1
  // Server: Microsoft-IIS/10.0
  // X-AspNet-Version: 4.0.30319
  // X-Powered-By: ASP.NET
  // Date: Wed, 19 Feb 2020 15:27:06 GMT
  // 
  // --------------080001080500020607080905
  // Content-Type: application/xop+xml; charset=iso-8859-1
  // Content-Id: RootPart
  // Content-Transfer-Encoding: binary
  // 
  // <?xml version="1.0" encoding="iso-8859-1"?>
  // <soapenv:Envelope xmlns:xcpt="...">
  //   <soapenv:Header />
  //   <soapenv:Body>
  //     <xres:Transport profile="http://something.example.com/..." version="1.4">
  //       <xres:TransportHeader>
  // 	...
  // 	...
  //       </xres:TransportHeader>
  //       <xres:TransportBody />
  //     </xres:Transport>
  //   </soapenv:Body>
  // </soapenv:Envelope>
  // --------------080001080500020607080905--

  // To get the XML, load the full MIME of the response into a Chilkat MIME object.  Then get the body of the 1st sub-part.
  final mime = CkMime();
  mime.loadMime(resp.fullMime);

  // Your code might verify that the Content-Type is indeed multipart/related.
  print(mime.contentType);
  print('num parts = ${mime.numParts}');

  // Assuming it is, and the number of sub-parts is > 0
  if (mime.numParts > 0) {

    final part0 = CkMime();
    mime.partAt(0, part0);

    // The Content-Type (in this ficticious example) should be "application/xop+xml"
    print('sub-part Content-Type: ${part0.contentType}');
    // Now get the XML 
    final subPartXmlBody = part0.getBodyDecoded();
    print(subPartXmlBody);
  }
}