Lua Requires Chilkat v10.0.0+

Demonstrate the Global.AutoQBDecode property

The Global.AutoQBDecode property can be set to _TRUE_ to cause Q/B encoded string arguments passed to any Chilkat method to be automatically decoded before being used. Lua

local chilkat = require("chilkat")

-- Turn on auto Q/B decoding for all strings passed to any Chilkat method in any Chilkat class.
local glob = chilkat.Global.new()
glob.auto_qb_decode = true

-- ---------------------------------------------------------------------------------------------------------------------------------------------
-- "Q" Encoding

-- Quoted-Printable encoding is primarily used for text that is mostly ASCII with some non-ASCII characters.
-- It encodes these characters in a way that remains mostly readable and compatible with ASCII-only systems.

-- How It Works with UTF-8:
-- - ASCII characters (except special characters like `=`) are encoded as themselves.
-- - Non-ASCII characters are represented by their UTF-8 byte values, each byte encoded as `=` followed by two hexadecimal digits.
--   For example, the UTF-8 character "é" (U+00E9) is encoded as `=C3=A9`.

-- For example, consider the text "Café" encoded in UTF-8. The UTF-8 bytes for "é" are `C3 A9`, so in Quoted-Printable, it looks like this:  Caf=C3=A9

-- The "Q" encoding has this syntax:  "=?charset?q?encoded_text?="
-- For example: "=?UTF-8?Q?Caf=C3=A9_announcement?="

-- ------
-- "B" Encoding

-- Base64 encoding is used to encode non-ASCII text, making it more suitable for text with a high density of non-ASCII characters, such as those found in non-Western European languages.

-- For example, consider the text "こんにちは" ("Hello" in Japanese).
-- The "B" encoded string would be "=?UTF-8?B?44GT44KT44Gr44Gh44Gv?="

-- ------
-- Q encoding is suitable for text that is mostly ASCII.
-- B Encoding is best for text that is densely packed with non-us-ascii chars, such as non-Latin (Asian) languages.
-- ---------------------------------------------------------------------------------------------------------------------------------------------

-- You can use Chilkat's online tool at Online Binary Encoder to pre-encode your literal strings before
-- inserting them into your source code.

-- When using the online tool, choose either "MIME header Q Encoding" or "MIME Header B Encoding".

-- For example:
local s_cafe = "=?utf-8?Q?Caf=C3=A9?="
local s1 = chilkat.StringBuilder.new()
s1:append(s_cafe)
print(s1:get_as_string())
-- Output is Café

local s_hello = "=?UTF-8?B?44GT44KT44Gr44Gh44Gv?="
local s2 = chilkat.StringBuilder.new()
s2:append(s_hello)
print(s2:get_as_string())
-- Output is こんにちは