Lua

Convert a MIME Entity to multipart/mixed

Demonstrates the Chilkat Mime.ConvertToMultipartMixed method, which wraps the current entity in a new outer multipart/mixed, making the original the first child. It takes no arguments.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This is how you turn an existing single-part message into one that can hold attachments — rather than rebuilding it, you wrap it, and its content becomes the first child of a new multipart/mixed. Message-level and custom headers are carried onto the new outer entity so the message identity is preserved. Afterward, AppendPartFromFile adds attachments beside the original body.

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Lua

local chilkat = require("chilkat")

local mime = chilkat.Mime.new()
local success = mime:load_mime_file("qa_data/message.eml")
if not success then
    print(mime.last_error_text)
    return
end

-- Wrap the current entity in a new outer multipart/mixed entity.  The original entity becomes the
-- first child, which is what you do to add attachments to an existing single-part message.
success = mime:convert_to_multipart_mixed()
if not success then
    print(mime.last_error_text)
    return
end

-- Now attachments can be appended alongside the original content.
success = mime:append_part_from_file("qa_data/report.pdf")
if not success then
    print(mime.last_error_text)
    return
end

print("Number of parts: " .. mime.num_parts)