Lua Requires Chilkat v11.0.0+

IMAP Search with THREAD Semantics

See more IMAP Examples

Demonstrates how to search an IMAP mailbox and return message numbers grouped together in parent/child relationships based on which messages are replies to others. Lua

local chilkat = require("chilkat")

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

local imap = chilkat.Imap.new()

-- Connect to your IMAP server and authenticate..
imap.ssl = true
imap.port = 993
local success = imap:connect("imap.mail.us-west-2.awsapps.com")
if not success then
    print(imap.last_error_text)
    return
end

success = imap:login("myLogin", "myPassword")
if not success then
    print(imap.last_error_text)
    return
end

-- Select a mailbox
success = imap:select_mailbox("Inbox")
if not success then
    print(imap.last_error_text)
    return
end

-- Search for all message having the letter 'a' somewhere in the Subject,
-- and return the messages as JSON.
local json = chilkat.JsonObject.new()
success = imap:query_thread("REFERENCES", "SUBJECT a", true, json)
if not success then
    print(imap.last_error_text)
    return
end

-- The IMAP server will return a raw response with a format such as this:  (2)(3 6 (4 23)(44 7 96))

-- In tree form, it's like this:
--
--             -- 2
--             -- 3
--                 \-- 6
--                    |-- 4
--                    |      \-- 23
--                    |
--                    |-- 44
--                               \-- 7
--                                       \-- 96
--

-- It means there are 2 main threads returned, but the 2nd thread splits into two sub-threads.
-- In total, we can think of it as 3 threads -- 2 main threads (with no parents) and one sub-thread w/ a parent.
--
-- - The 1st thread contains the message 2, and has no parent thread.
-- - The 2nd thread contains the messages 3, 6, 4, 23, and has no parent thread.
-- - The 3rd thread contains the messages 44, 7, 96 and the parent thread is message 6.
--

-- (Yes, this is all highly confusing...)

-- Chilkat will return the above sample response as JSON that looks like this:

-- {
--   "threads": [
--     [2],
--     [3, 6, [4, 23], [44, 7, 96]]
--   ]
-- }
--

-- Use this online tool to generate parsing code from sample JSON:
-- Generate Parsing Code from JSON
-- In this case, the online tool can help you get a feel for how to write the JSON parsing code..

local numThreads = json:size_of_array("threads")
print("The total number of top-level threads is " .. numThreads)

-- Let's say we wanted to get the messages in the thread 3, 6, 4, 23.
-- We always follow the 1st branch to the bottom, ignoring the other branches.
-- For example, if we had  [3, 5, [4, 23, [55, 56, 57], [68, 69]], [44, 7, 96]]
-- then the thread would be 3, 5, 4, 43, 55, 56, 57

-- For testing, let's substitute the response from the IMAP server with this sample:
json:load("{\"threads\": [[2], [3, 5, [4, 23, [55, 56, 57], [68, 69]], [44, 7, 96]]]}")

-- Begin with the 2nd top-level thread, which is at index 1.
print("Following the 2nd top level thread...")
local arr = json:array_of("threads[1]")
local threadSize = arr.size
local i = 0
while i < threadSize do
    -- Do we have an array or integer at this position?
    if arr:type_at(i) == 4 then
        -- This is a sub-array.
        local subArr = arr:array_at(i)

        -- Follow the sub-array starting at the 1st position..
        arr = subArr
        i = 0
        threadSize = arr.size
    else
        -- Must be a single integer.
        print(arr:int_at(i))
        i = i + 1
    end
end

-- The output is:
--
-- Following the 2nd top level thread...
-- 3
-- 5
-- 4
-- 23
-- 55
-- 56
-- 57