(Objective-C) Build a multipart/related MIME Message

Demonstrates how to construct a multipart/related MIME message containing HTML and a related JPG image.

Chilkat Objective-C Library Downloads

MAC OS X (Cocoa) Libs

iOS Libs

#import <CkoMime.h>
#import <CkoCrypt2.h>
#import <CkoStringBuilder.h>
#import <CkoFileAccess.h>

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

BOOL success;

// Start with an empty MIME object...
CkoMime *mime = [[CkoMime alloc] init];

// Initialize it as multipart/related.
[mime NewMultipartRelated];

// Set a top-level MIME header field.
[mime SetHeaderField: @"Subject" value: @"Test HTML email with JPG image."];

// Generate a Content-ID.  This will contain random data that will allow
// the HTML's "img" tag to reference the image part in the MIME.
CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];
crypt.EncodingMode = @"hex";

CkoStringBuilder *sbContentId = [[CkoStringBuilder alloc] init];
[sbContentId Append: @"part1."];
[sbContentId Append: [crypt GenRandomBytesENC: [NSNumber numberWithInt: 4]]];
[sbContentId Append: @"."];
[sbContentId Append: [crypt GenRandomBytesENC: [NSNumber numberWithInt: 4]]];
[sbContentId Append: @"@chilkatsoft.com"];

// Create the HTML body.
CkoStringBuilder *sbHtml = [[CkoStringBuilder alloc] init];
[sbHtml Append: @"<html><head>\r\n"];
[sbHtml Append: @"<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">\r\n"];
[sbHtml Append: @"  </head>\r\n"];
[sbHtml Append: @"  <body bgcolor=\"#FFFFFF\" text=\"#000000\">\r\n"];
[sbHtml Append: @"    <p>This is a test.&nbsp; <img src=\"cid:CONTENT_ID\" height=\"20\" width=\"20\"></p>\r\n"];
[sbHtml Append: @"  </body>\r\n"];
[sbHtml Append: @"</html>\r\n"];
int numReplacements = [[sbHtml Replace: @"CONTENT_ID" replacement: [sbContentId GetAsString]] intValue];

// Create the HTML MIME part.
CkoMime *htmlMime = [[CkoMime alloc] init];
[htmlMime SetBodyFromHtml: [sbHtml GetAsString]];
htmlMime.Encoding = @"8bit";
htmlMime.Charset = @"utf-8";

// Load our JPG image from a file.
CkoFileAccess *fac = [[CkoFileAccess alloc] init];
NSData jpgBytes;
jpgBytes = [fac ReadEntireFile: @"qa_data/jpg/starfish20.jpg"];

// Create an image/jpeg MIME part.
CkoMime *jpgMime = [[CkoMime alloc] init];
[jpgMime SetBodyFromBinary: jpgBytes];
// Setting the following properties has the effect of adding
// the Content-Type, Content-Transfer-Encoding, and Content-Disposition header fields.
// These header fields could also be set via the SetHeaderField method, in which case
// the values of the affected properties would be updated.
jpgMime.ContentType = @"image/jpeg";
jpgMime.Name = @"starfish20.jpg";
jpgMime.Encoding = @"base64";
jpgMime.Disposition = @"inline";
jpgMime.Filename = @"starfish20.jpg";

CkoStringBuilder *sbContentIdHdr = [[CkoStringBuilder alloc] init];
[sbContentIdHdr Append: @"<CONTENT_ID>"];
numReplacements = [[sbContentIdHdr Replace: @"CONTENT_ID" replacement: [sbContentId GetAsString]] intValue];
[jpgMime SetHeaderField: @"Content-ID" value: [sbContentIdHdr GetAsString]];

// Add both parts as children of the multipart/related
[mime AppendPart: htmlMime];
[mime AppendPart: jpgMime];
NSLog(@"%@",[mime GetMime]);

// --------------------------------------------------------------
// --------------------------------------------------------------
// This example builds the following MIME message.  The boundary
// and Content-ID strings contain random data and will be different.  

// Content-Type: multipart/related; boundary="------------A940F1230E6F0105F03DB2CB"
// Subject: Test HTML email with JPG image.
// 
// --------------A940F1230E6F0105F03DB2CB
// Content-Type: text/html; charset="utf-8"
// Content-Transfer-Encoding: 8bit
// 
// <html><head>
// <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
//   </head>
//   <body bgcolor="#FFFFFF" text="#000000">
//     <p>This is a test.&nbsp; <img src="cid:part1.E16AE3B4.1505C436@chilkatsoft.com" height="20" width="20"></p>
//   </body>
// </html>
// 
// --------------A940F1230E6F0105F03DB2CB
// Content-Transfer-Encoding: base64
// Content-Type: image/jpeg; name="starfish20.jpg"
// Content-Disposition: inline; filename="starfish20.jpg"
// Content-ID: <part1.E16AE3B4.1505C436@chilkatsoft.com>
// 
// /9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcD8g
// NC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBEV0U3OFBtUVdf
// YmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj
// Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/EABcAAAMBAAAA
// AAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQACEAMQAAAB2kZY
// NNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgBAQABBQL0XqN+
// pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgBAwEBPwHqU5aq
// Axx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIBAT8B3Bhqy7Zc
// enyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEBAAY/ArZyn+Cg
// xtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEAAT8hkEwPUUR9
// DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAAAAAAAAAAAAAA
// AAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAAAAAAAAAAAREA
// QRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAAAAABEQAhMUFx
// EFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO/n//2Q==
// 
// --------------A940F1230E6F0105F03DB2CB--
//