Lua

Add a Related Item from a BinData Object

Demonstrates the Chilkat Email.AddRelatedBd method, which adds a related item (such as an inline image) using the contents of a BinData object, and returns the generated Content-ID. This example loads an image into a BinData, adds it, captures the Content-ID, and references it from the HTML body.

Background: This is the binary, Content-ID-based way to embed an inline resource — the right choice for images, whose bytes belong in a BinData rather than a string. Because Chilkat generates the Content-ID, the usual pattern is: add the item first, capture the returned ID, then build the matching <img src="cid:..."> reference from it (done here with a StringBuilder).

Chilkat Lua Downloads

Download Chilkat for Lua

Lua

local chilkat = require("chilkat")

-- Demonstrates the AddRelatedBd method, which adds a related item (such as an inline image)
-- using the contents of a BinData object, and returns the generated Content-ID.

local email = chilkat.Email.new()
email.subject = "Related image from BinData"

-- Load the image data from a file into a BinData object.
local bdImage = chilkat.BinData.new()
local success = bdImage:load_file("qa_data/images/logo.png")
if not success then
    print(bdImage.last_error_text)
    return
end

-- Add the image as a related item; capture its generated Content-ID.
local cid = email:add_related_bd("logo.png", bdImage)
if not email.last_method_success then
    print(email.last_error_text)
    return
end

-- Reference the related item in the HTML body by its Content-ID.
local sbHtml = chilkat.StringBuilder.new()
sbHtml:append("<html><body><img src=\"cid:PLACEHOLDER_CID\"/></body></html>")
local numReplaced = sbHtml:replace("PLACEHOLDER_CID", cid)
email:set_html_body(sbHtml:get_as_string())

print("NumRelatedItems = " .. email.num_related_items)

-- Note: The path "qa_data/images/logo.png" is a relative local filesystem path,
-- relative to the current working directory of the running application.