(Ruby) Add, Remove, Update MIME Header Fields

Demonstrates how to add, remove, or update the content of MIME header fields.

Chilkat Ruby Downloads

install from rubygems.org
gem install chilkat
or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

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

mime = Chilkat::CkMime.new()

# The contents of this MIME file are shown below, 
# and is also available at https://www.chilkatsoft.com/sampleMime.txt
success = mime.LoadMimeFile("qa_data/mime/sampleMime.txt")
if (success != true)
    print mime.lastErrorText() + "\n";
    exit
end

# The MIME used in this example has the following nested structure
# 
# multipart/alternative
#     text/plain
#     multipart/related
#         text/html
#         image/jpeg
# 

# Adding a top-level MIME header is easy.
mime.AddHeaderField("hello-world","Hello World!")
# If a header field of the same name already exists, the AddHeaderField
# method adds a duplicate.
mime.AddHeaderField("Subject","This is the 2nd Subject header.")
print mime.getEntireHead() + "\n";
print "-" + "\n";

# The top-level header now looks like this:
# 
# 	Subject: Test email.
# 	Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
# 	MIME-Version: 1.0
# 	hello-world: Hello World!
# 	Subject: This is the 2nd Subject header.
# 

# The RemoveHeaderField method can remove the 1st occurrance, or all occurrences.
bAllOccurrences = true
# Remove all occurrences of the Subject header;
mime.RemoveHeaderField("Subject",bAllOccurrences)
print mime.getEntireHead() + "\n";
print "-" + "\n";

# After removing all Subject header fields, the top-level header now looks like this:
# 
# Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
# MIME-Version: 1.0
# hello-world: Hello World!
# 

# The content of a header field can be updated by calling SetHeaderField.
# If the header field does not already exist, it is added.  Otherwise it is updated.
# Note: The order of header fields SHOULD never matter.
mime.SetHeaderField("hello-world","Goodbye World.")
print mime.getEntireHead() + "\n";
print "-" + "\n";

# Now we have:
# 
# 	Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
# 	MIME-Version: 1.0
# 	hello-world: Goodbye World.
# 

# To add/update/delete header fields in sub-parts, navigate to
# the sub-part and do the same..

# mpRelated is a CkMime
mpRelated = mime.GetPart(1)
# pJpg is a CkMime
pJpg = mpRelated.GetPart(1)

# Add a header to the image/jpeg sub-header.
pJpg.SetHeaderField("CustomHeader","This is the custom header value.")

# View the entire MIME..
print mime.getMime() + "\n";

# --------------------------------------------------------------
# --------------------------------------------------------------
# The MIME sample file loaded at the beginning of this example
# contains the following MIME:

# Subject: Test email.
# Content-Type: multipart/alternative;
# 	boundary="------------DB171738719FB06D67DEBAA0"
# MIME-Version: 1.0
# 
# --------------DB171738719FB06D67DEBAA0
# Content-Type: text/plain; charset="utf-8"; format=flowed
# Content-Transfer-Encoding: 7bit
# 
# This is a test.
# 
# --------------DB171738719FB06D67DEBAA0
# Content-Type: multipart/related;
# 	boundary="------------A940F1230E6F0105F03DB2CB"
# 
# --------------A940F1230E6F0105F03DB2CB
# Content-Type: text/html; charset="utf-8"
# Content-Transfer-Encoding: 8bit
# 
# <html><head>
# <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
#   </head>
#   <body bgcolor="#FFFFFF" text="#000000">
#     <p>This is a test.&nbsp; <img src="cid:part1.E16AE3B4.1505C436@chilkatsoft.com" height="20" width="20"></p>
#   </body>
# </html>
# 
# --------------A940F1230E6F0105F03DB2CB
# Content-Type: image/jpeg; name="starfish20.jpg"
# Content-Transfer-Encoding: base64
# Content-ID: <part1.E16AE3B4.1505C436@chilkatsoft.com>
# Content-Disposition: inline; filename="starfish20.jpg"
# 
# /9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcD8g
# NC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBEV0U3OFBtUVdf
# YmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj
# Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/EABcAAAMBAAAA
# AAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQACEAMQAAAB2kZY
# NNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgBAQABBQL0XqN+
# pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgBAwEBPwHqU5aq
# Axx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIBAT8B3Bhqy7Zc
# enyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEBAAY/ArZyn+Cg
# xtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEAAT8hkEwPUUR9
# DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAAAAAAAAAAAAAA
# AAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAAAAAAAAAAAREA
# QRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAAAAABEQAhMUFx
# EFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO/n//2Q==
# 
# --------------A940F1230E6F0105F03DB2CB--
# 
# --------------DB171738719FB06D67DEBAA0--
#