Lua Requires Chilkat v11.7.0+

QR Code Numeric, Alphanumeric and Byte Modes

See more QR Code Examples

Demonstrates the QR encoding modes. Digits alone are stored in numeric mode, and text made only of digits, upper-case letters, space and $ % * + - . / : in alphanumeric mode. Both pack more characters into a symbol than byte mode, which is used for everything else. QrCode chooses the most compact mode the text allows, and the response reports it. A product code written in upper case therefore gives a smaller symbol than the same code in lower case. Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local fmt = chilkat.Formats.new()
local json = chilkat.JsonObject.new()
local jsonOut = chilkat.JsonObject.new()

-- Digits only.
json:update_string("payload.text", "00123456789012345678")
local success = fmt:qr_code("generate", json, jsonOut)
if not success then
    print(fmt.last_error_text)
    return
end

print("digits: mode " .. jsonOut:string_of("symbols[0].selectedEncoding.mode") .. ", version " .. jsonOut:int_of("symbols[0].selectedEncoding.version"))

-- Upper-case letters, digits, space and - are all in the alphanumeric set.
json:update_string("payload.text", "ORDER-12345 LOT A7 SHELF 12-C")
success = fmt:qr_code("generate", json, jsonOut)
if not success then
    print(fmt.last_error_text)
    return
end

print("upper case: mode " .. jsonOut:string_of("symbols[0].selectedEncoding.mode") .. ", version " .. jsonOut:int_of("symbols[0].selectedEncoding.version"))

-- Lower-case letters are not, so the same text in lower case needs byte mode.
json:update_string("payload.text", "order-12345 lot a7 shelf 12-c")
success = fmt:qr_code("generate", json, jsonOut)
if not success then
    print(fmt.last_error_text)
    return
end

print("lower case: mode " .. jsonOut:string_of("symbols[0].selectedEncoding.mode") .. ", version " .. jsonOut:int_of("symbols[0].selectedEncoding.version"))

-- The mode can be named.  Byte mode can hold any text.  Naming a mode the text cannot use
-- (numeric for text with letters, for example) fails with conflictingOptions.
json:update_string("payload.text", "00123456789012345678")
json:update_string("encoding.qr.mode", "byte")
success = fmt:qr_code("generate", json, jsonOut)
if not success then
    print(fmt.last_error_text)
    return
end

print("digits as bytes: mode " .. jsonOut:string_of("symbols[0].selectedEncoding.mode") .. ", version " .. jsonOut:int_of("symbols[0].selectedEncoding.version"))

-- The four symbols, in the order they were made:

-- 

-- Sample output:

-- digits: mode numeric, version 1
-- upper case: mode alphanumeric, version 2
-- lower case: mode byte, version 3
-- digits as bytes: mode byte, version 2