(Xojo Plugin) Build a multipart/related MIME Message

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

Chilkat Xojo Plugin Download

Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

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

Dim success As Boolean

// Start with an empty MIME object...
Dim mime As New Chilkat.Mime

// Initialize it as multipart/related.
success = mime.NewMultipartRelated()

// Set a top-level MIME header field.
success = mime.SetHeaderField("Subject","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.
Dim crypt As New Chilkat.Crypt2
crypt.EncodingMode = "hex"

Dim sbContentId As New Chilkat.StringBuilder
success = sbContentId.Append("part1.")
success = sbContentId.Append(crypt.GenRandomBytesENC(4))
success = sbContentId.Append(".")
success = sbContentId.Append(crypt.GenRandomBytesENC(4))
success = sbContentId.Append("@chilkatsoft.com")

// Create the HTML body.
Dim sbHtml As New Chilkat.StringBuilder
success = sbHtml.Append("<html><head>" + EndOfLine.Windows)
success = sbHtml.Append("<meta http-equiv=""Content-Type"" content=""text/html; charset=utf-8"">" + EndOfLine.Windows)
success = sbHtml.Append("  </head>" + EndOfLine.Windows)
success = sbHtml.Append("  <body bgcolor=""#FFFFFF"" text=""#000000"">" + EndOfLine.Windows)
success = sbHtml.Append("    <p>This is a test.&nbsp; <img src=""cid:CONTENT_ID"" height=""20"" width=""20""></p>" + EndOfLine.Windows)
success = sbHtml.Append("  </body>" + EndOfLine.Windows)
success = sbHtml.Append("</html>" + EndOfLine.Windows)
Dim numReplacements As Int32
numReplacements = sbHtml.Replace("CONTENT_ID",sbContentId.GetAsString())

// Create the HTML MIME part.
Dim htmlMime As New Chilkat.Mime
success = htmlMime.SetBodyFromHtml(sbHtml.GetAsString())
htmlMime.Encoding = "8bit"
htmlMime.Charset = "utf-8"

// Load our JPG image from a file.
Dim fac As New Chilkat.FileAccess
Dim jpgBytes As MemoryBlock
jpgBytes = fac.ReadEntireFile("qa_data/jpg/starfish20.jpg")

// Create an image/jpeg MIME part.
Dim jpgMime As New Chilkat.Mime
success = 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"

Dim sbContentIdHdr As New Chilkat.StringBuilder
success = sbContentIdHdr.Append("<CONTENT_ID>")
numReplacements = sbContentIdHdr.Replace("CONTENT_ID",sbContentId.GetAsString())
success = jpgMime.SetHeaderField("Content-ID",sbContentIdHdr.GetAsString())

// Add both parts as children of the multipart/related
success = mime.AppendPart(htmlMime)
success = mime.AppendPart(jpgMime)
System.DebugLog(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--
//