Lua

Save an Email to a Temporary MHT File

Demonstrates the Chilkat Email.CreateTempMht method, which prepares the email for display in a web browser and saves it as a temporary MHT file, returning the path that was written. If the filename argument is empty, Chilkat chooses a temporary filename.

To make the message viewable as a standalone web page, the method transforms it: all attachments are dropped; if the email has both HTML and plain-text alternatives, the plain-text alternative is dropped; and if the email has only a plain-text body, it is converted to HTML. This example loads an HTML email and creates the temporary MHT.

Background: MHT (MIME HTML) is a single-file web-page-archive format — it packs an HTML document together with its images and style sheets into one file, which is essentially what an HTML email already is. Because a Windows WebBrowser control can navigate directly to an .mht file, writing the message out as MHT is a quick way to render a received email, inline images and all, inside a desktop application. The transformations (dropping attachments, keeping just the HTML representation) ensure the result is a clean, self-contained page. For unpacking to loose files served by a web application instead, see AspUnpack.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the CreateTempMht method, which prepares the email for viewing in a browser
-- and saves it as a temporary MHT (MIME HTML) file, returning the file path.
--
-- To produce browser-viewable output, CreateTempMht transforms the message: it drops all
-- attachments; if the email has both HTML and plain-text alternatives it drops the
-- plain-text alternative; and if the email has only a plain-text body it converts that
-- body to HTML.  Passing an empty filename lets Chilkat choose a temporary filename.

local email = chilkat.Email.new()

local success = email:load_eml("qa_data/eml/html_with_images.eml")
if not success then
    print(email.last_error_text)
    return
end

-- Transform the email for browser display and save it as a temporary MHT file
-- (empty filename = auto-generated temp file).
local mhtPath = email:create_temp_mht("")

print("Temporary MHT file: " .. mhtPath)

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