(Objective-C) How to Access Parts of a multipart/related HTTP Response

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 ...

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#import <CkoHttp.h>
#import <CkoXml.h>
#import <NSString.h>
#import <CkoHttpRequest.h>
#import <CkoHttpResponse.h>
#import <CkoMime.h>

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

CkoHttp *http = [[CkoHttp alloc] init];

CkoXml *soapXml = [[CkoXml alloc] init];

// 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" value: @"http://schemas.xmlsoap.org/soap/envelope/"];
[soapXml UpdateAttrAt: @"soap:Body|Detail" autoCreate: YES attrName: @"xmlns" attrValue: @"http://example.org/mtom/data"];
[soapXml UpdateAttrAt: @"soap:Body|Detail|image|xop:Include" autoCreate: YES attrName: @"xmlns:xop" attrValue: @"http://www.w3.org/2004/08/xop/include"];
[soapXml UpdateAttrAt: @"soap:Body|Detail|image|xop:Include" autoCreate: YES attrName: @"href" attrValue: @"cid:5aeaa450-17f0-4484-b845-a8480c363444@example.org"];

soapXml.EmitXmlDecl = NO;
NSString *xmlBody = [soapXml GetXml];
NSLog(@"%@",xmlBody);

CkoHttpRequest *req = [[CkoHttpRequest alloc] init];
req.HttpVerb = @"POST";
req.Path = @"/something/someTarget";

req.ContentType = @"multipart/related; start-info=\"text/xml\"; type=\"application/xop+xml\"";
[req AddHeader: @"SOAPAction" value: @"some-SOAP-action"];

success = [req AddStringForUpload2: @"" filename: @"" strData: xmlBody charset: @"utf-8" contentType: @"application/xop+xml; type=\"text/xml\"; charset=utf-8"];

// The bytes will be sent as binary (not base64 encoded).
success = [req AddFileForUpload2: @"" path: @"qa_data/jpg/starfish.jpg" contentType: @"image/jpeg"];

// The JPEG data is the 2nd sub-part, and therefore is at index 1 (the first sub-part is at index 0)
success = [req AddSubHeader: [NSNumber numberWithInt: 1] name: @"Content-ID" value: @"<5aeaa450-17f0-4484-b845-a8480c363444@example.org>"];

http.FollowRedirects = YES;

BOOL useTls = YES;
CkoHttpResponse *resp = [http SynchronousRequest: @"www.example.org" port: [NSNumber numberWithInt: 443] ssl: useTls req: req];
if (http.LastMethodSuccess != YES) {
    NSLog(@"%@",http.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.
CkoMime *mime = [[CkoMime alloc] init];
[mime LoadMime: resp.FullMime];

// Your code might verify that the Content-Type is indeed multipart/related.
NSLog(@"%@",mime.ContentType);
NSLog(@"%@%d",@"num parts = ",[mime.NumParts intValue]);

// Assuming it is, and the number of sub-parts is > 0
if ([mime.NumParts intValue] > 0) {
    CkoMime *part0 = [mime GetPart: [NSNumber numberWithInt: 0]];
    // The Content-Type (in this ficticious example) should be "application/xop+xml"
    NSLog(@"%@%@",@"sub-part Content-Type: ",part0.ContentType);
    // Now get the XML 
    NSString *subPartXmlBody = [part0 GetBodyDecoded];
    NSLog(@"%@",subPartXmlBody);

}