Lua

Access a Part in a Multipart MIME Entity

Demonstrates the Chilkat Mime.PartAt method, which provides live access to the direct child at a zero-based index. The first argument is the index and the second is a Mime object that will reference the child. Modifying it modifies the child stored in the parent tree.

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 reach into a multipart message to inspect or edit an individual part — read a part's Content-Type, extract an attachment's body, or change a part in place. The key point is that the returned Mime is a live reference, not a copy, so edits to it flow back into the parent tree. Loop from 0 to NumParts - 1 to visit every direct child.

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Lua

local chilkat = require("chilkat")

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

-- PartAt provides LIVE access to a direct child part.  The 1st argument is the zero-based index
-- and the 2nd is a Mime object that will reference the child.  Modifying it modifies the child in
-- the parent tree.
local n = mime.num_parts
print("Number of parts: " .. n)

local part = chilkat.Mime.new()
for i = 0, n - 1 do
    success = mime:part_at(i, part)
    if not success then
        print(mime.last_error_text)
        return
    end

    print("Part " .. i .. " Content-Type: " .. part.content_type)
end