Lua
Build a multipart/related MIME Message

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

Lua
local chilkat = require("chilkat")

local success = false

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

-- Start with an empty MIME object...
local mime = chilkat.Mime.new()

-- Initialize it as multipart/related.
mime:new_multipart_related()

-- Set a top-level MIME header field.
mime:set_header_field("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.
local crypt = chilkat.Crypt2.new()
crypt.encoding_mode = "hex"

local sbContentId = chilkat.StringBuilder.new()
sbContentId:append("part1.")
sbContentId:append(crypt:gen_random_bytes_enc(4))
sbContentId:append(".")
sbContentId:append(crypt:gen_random_bytes_enc(4))
sbContentId:append("@chilkatsoft.com")

-- Create the HTML body.
local sbHtml = chilkat.StringBuilder.new()
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")
local numReplacements = sbHtml:replace("CONTENT_ID", sbContentId:get_as_string())

-- Create the HTML MIME part.
local htmlMime = chilkat.Mime.new()
htmlMime:set_body_from_html(sbHtml:get_as_string())
htmlMime.encoding = "8bit"
htmlMime.charset = "utf-8"

-- Load our JPG image from a file.
local fac = chilkat.FileAccess.new()

jpgBytes = ERROR: Method not in Chilkat for Lua: FileAccess.ReadEntireFile
fac:ERROR()

-- Create an image/jpeg MIME part.
local jpgMime = chilkat.Mime.new()
ERROR: Method not in Chilkat for Lua: Mime.SetBodyFromBinary
jpgMime:ERROR()
-- 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.content_type = "image/jpeg"
jpgMime.name = "starfish20.jpg"
jpgMime.encoding = "base64"
jpgMime.disposition = "inline"
jpgMime.filename = "starfish20.jpg"

local sbContentIdHdr = chilkat.StringBuilder.new()
sbContentIdHdr:append("<CONTENT_ID>")
numReplacements = sbContentIdHdr:replace("CONTENT_ID", sbContentId:get_as_string())
jpgMime:set_header_field("Content-ID", sbContentIdHdr:get_as_string())

-- Add both parts as children of the multipart/related
mime:append_part(htmlMime)
mime:append_part(jpgMime)
print(mime:get_mime())

-- --------------------------------------------------------------
-- --------------------------------------------------------------
-- 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--
--