Lua Requires Chilkat v9.5.0.91+

Using Replace Patterns in Email

See more Email Object Examples

Demonstrates how to use the replace patterns (mail-merge) feature in Chilkat MailMan. Lua

local chilkat = require("chilkat")

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

-- ---------------------------------------------------------------------
-- Create an email template for sending.
local emailTemplate = chilkat.Email.new()

-- We're going to replace "FIRST_NAME" with an actual name.
-- We arbitrarily chose "FIRST_NAME".  We can choose anything, such as "CUSTOMER_NAME" or "THE_RECIPIENT_NAME"...
emailTemplate.subject = "Hello FIRST_NAME,"

emailTemplate.from = "john@example.com"
emailTemplate:add_to("FIRST_NAME", "RECIPIENT_EMAIL")

emailTemplate:set_html_body("<html><body><h2>Hello FIRST_NAME,</h2><p>Your order for PRODUCT_NAME has been shipped.</p></body></html>")

-- If the email is saved to a file, we can see what it contains:
emailTemplate:save_eml("qa_output/emailTemplate.eml")

-- For example:

-- MIME-Version: 1.0
-- Date: Tue, 26 Apr 2022 07:10:52 -0500
-- Message-ID: <715CF231A9F07B0B9FDB073518CD94138D791866@XYZ>
-- Content-Type: text/html; charset=us-ascii
-- Content-Transfer-Encoding: 7bit
-- X-Priority: 3 (Normal)
-- Subject: Hello FIRST_NAME,
-- From: john@example.com
-- To: FIRST_NAME <RECIPIENT_EMAIL>
--
-- <html><body><h2>Hello FIRST_NAME,</h2><p>Your order for PRODUCT_NAME has been shipped.</p></body></html>

-- ---------------------------------------------------------------------
-- Demonstrate replace patterns by setting and then rendering to MIME.

local mailman = chilkat.MailMan.new()

emailTemplate:set_replace_pattern("FIRST_NAME", "Elon")
emailTemplate:set_replace_pattern("RECIPIENT_EMAIL", "elon.musk@example.com")
emailTemplate:set_replace_pattern("PRODUCT_NAME", "Twitter Corporation")

-- Render to MIME to see what we get.
-- Note: When the MailMan sends an email, it renders the email to MIME and then sends.
-- The rendering process is to do replacements, or possibly sign, encrypt, etc.
-- When MailMan.SendEmail is called, internally the email is rendered, and the rendered email is sent.
-- The equivalent to MailMan.Send email is to call email.RenderToMime followed by MailMan.SendMime.
local mime = mailman:render_to_mime(emailTemplate)
print(mime)

-- This is the rendered MIME:

-- MIME-Version: 1.0
-- Date: Tue, 26 Apr 2022 07:25:49 -0500
-- Message-ID: <750582BCDC891C67B48CEE2293C08B902C3891E9@XYZ>
-- Content-Type: text/html; charset=us-ascii
-- Content-Transfer-Encoding: 7bit
-- X-Priority: 3 (Normal)
-- Subject: Hello Elon,
-- From: john@example.com
-- To: Elon <elon.musk@example.com>
--
-- <html><body><h2>Hello Elon,</h2><p>Your order for Twitter Corporation has been shipped.</p></body></html>

-- Note: When rendering, the Date and Message-ID headers are automatically regenerated.

-- ---------------------------------------------------------------------
-- An application can see what replacement patterns it previously set by calling SetReplacePattern multiple times.
local count = emailTemplate.num_replace_patterns
print("Number of replace patterns: " .. count)

local i = 0
while i < count do
    print(emailTemplate:get_replace_pattern(i) .. ": " .. emailTemplate:get_replace_string(i))
    i = i + 1
end

-- Or lookup a replacement pattern by name:
local name = "FIRST_NAME"
print(name .. " = " .. emailTemplate:get_replace_string2(name))

-- Sample output:

-- Number of replace patterns: 3
-- FIRST_NAME: Elon
-- RECIPIENT_EMAIL: elon.musk@example.com
-- PRODUCT_NAME: Twitter Corporation
-- FIRST_NAME = Elon

-- ---------------------------------------------------------------------
-- Finally... demonstrate sending emails using the replacement patterns.
--

-- Set our mail server settings..
mailman.smtp_host = "smtp.mail.us-west-2.awsapps.com"
mailman.smtp_ssl = true
mailman.smtp_port = 465

mailman.smtp_username = "john@example.com"
mailman.smtp_password = "the_password"

-- Imagine we have data in JSON format, and we wish to send the templated email to each recipient...
--

-- {
--     "mail_merge" : [
--         {
--             "to": "mary@example.com",
--             "name": "Mary",
--             "product": "Widget 1"
--         },
--         {
--             "to": "robert@example.com",
--             "name": "Robert",
--             "product": "Widget 2"
--         }
--         ...
--     ]
-- }

local json = chilkat.JsonObject.new()
local success = json:load_file("qa_data/json/mail_merge.json")
if not success then
    print(json.last_error_text)
    return
end

local emailAddr = ""
local firstName = ""
local product = ""

i = 0
count = json:size_of_array("mail_merge")
while i < count do
    json.i = i
    emailAddr = json:string_of("mail_merge[i].to")
    firstName = json:string_of("mail_merge[i].name")
    product = json:string_of("mail_merge[i].product")

    emailTemplate:set_replace_pattern("FIRST_NAME", firstName)
    emailTemplate:set_replace_pattern("RECIPIENT_EMAIL", emailAddr)
    emailTemplate:set_replace_pattern("PRODUCT_NAME", product)

    success = mailman:send_email(emailTemplate)
    if not success then
        print(mailman.last_error_text)
        return
    end

    print("Send email to " .. emailAddr)

    i = i + 1
end

print("Success.")