(Tcl) Create Binary MIME

Demonstrates how to create and save a multipart/mixed MIME document where the parts (a JPG and a PDF) are NOT base64 encoded, but are instead binary.

Note: This example requires Chilkat v9.5.0.62 or greater.

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load ./chilkat.dll

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

set mime [new_CkMime]

CkMime_SetBodyFromPlainText $mime "This is the plain text body."
CkMime_ConvertToMultipartMixed $mime
CkMime_AppendPartFromFile $mime "qa_data/jpg/penguins.jpg"
CkMime_AppendPartFromFile $mime "qa_data/pdf/fishing.pdf"

# At this point, when saved, the MIME bodies will be base64 encoded.
CkMime_SaveMime $mime "qa_output/sample.txt"

# We now have the following MIME where everything is base64 encoded:
# The code that follows shows how to eliminate the base64 to make this binary MIME.

# 	Content-Type: multipart/mixed; boundary="------------000207060703080505060404"
# 
# 	--------------000207060703080505060404
# 	Content-Type: text/plain
# 	Content-Transfer-Encoding: 7bit
# 
# 	This is the plain text body.
# 	--------------000207060703080505060404
# 	Content-Disposition: attachment; filename="penguins.jpg"
# 	Content-Type: image/jpeg; name="penguins.jpg"
# 	Content-Transfer-Encoding: base64
# 
# 	/9j/4AAQSkZJRgABAgEAYABgAAD/7gAOQWRvYmUAZAAAAAAB/+ESCEV4aWYAAE1NACoAAAAIAAcB
# 	MgACAAAAFAAAAGIBOwACAAAABwAAAHZHRgADAAAAAQAEAABHSQADAAAAAQA/AACcnQABAAAADgAA
# 	...
# 	800a1MlLipJHlyU9en7sqVPkBK+gBj+o+1E91Ld7iJk0pJDO5PmDk4FOGOHy6S3JW120W1uCJ5M0
# 	PBa54edOFAc8ePX/2Q==
# 
# 	--------------000207060703080505060404
# 	Content-Disposition: attachment; filename="fishing.pdf"
# 	Content-Type: application/pdf; name="fishing.pdf"
# 	Content-Transfer-Encoding: base64
# 
# 	JVBERi0xLjMKJcfsj6IKNSAwIG9iago8PC9MZW5ndGggNiAwIFIvRmlsdGVyIC9GbGF0ZURlY29k
# 	ZT4+CnN0cmVhbQp4nM1c288cNxVX09A0myq35tom7bSl8E1hp76P/YpASIiXlEg8tDwVKEJfilIe
# 	...
# 	MDRGMT48OTlENkRFQzExQjkzNjA0Mjc1RUFCNzIyMjI4RjA0RjE+XQo+PgpzdGFydHhyZWYKMjk0
# 	MzY5CiUlRU9GCg==
# 
# 	--------------000207060703080505060404--
# 

# To make it binary MIME (getting rid of the base64), set the Encoding property to "binary"
# for the JPG and PDF parts.
# jpgPart is a CkMime
set jpgPart [CkMime_GetPart $mime 1]
CkMime_put_Encoding $jpgPart "binary"
delete_CkMime $jpgPart

# pdfPart is a CkMime
set pdfPart [CkMime_GetPart $mime 2]
CkMime_put_Encoding $pdfPart "binary"
delete_CkMime $pdfPart

# Now save it.  If you try to view this MIME in a text editor,
# the JPG and PDF parts will be garbled and unintelligible. That's because
# the bytes do not represent characters.
CkMime_SaveMime $mime "qa_output/sampleBinary.mim"

# The MIME now contains this:

# 	Content-Type: multipart/mixed; boundary="------------000207060703080505060404"
# 
# 	--------------000207060703080505060404
# 	Content-Type: text/plain
# 	Content-Transfer-Encoding: 7bit
# 
# 	This is the plain text body.
# 	--------------000207060703080505060404
# 	Content-Disposition: attachment; filename="penguins.jpg"
# 	Content-Type: image/jpeg; name="penguins.jpg"
# 	Content-Transfer-Encoding: binary
# 
# 	<Binary Data Here>
# 
# 	--------------000207060703080505060404
# 	Content-Disposition: attachment; filename="fishing.pdf"
# 	Content-Type: application/pdf; name="fishing.pdf"
# 	Content-Transfer-Encoding: binary
# 
# 	<Binary Data Here>
# 
# 	--------------000207060703080505060404--
# 

# Can we load this binary MIME into an Email object?
set binData [new_CkBinData]

# Write the binary MIME into binData;
CkMime_GetMimeBd $mime $binData

set email [new_CkEmail]

# Load the email from the binData.
CkEmail_SetFromMimeBd $email $binData

# Note: Many email clients may not be able to correctly process emails
# using the binary encoding.  Thunderbird has trouble.  Windows Live Mail
# worked OK.
CkEmail_put_Subject $email "Binary MIME Email"
CkEmail_put_From $email "admin@chilkatsoft.com"
CkEmail_AddTo $email "Chilkat" "support@chilkatsoft.com"
CkEmail_SaveEml $email "qa_output/binaryEmail.eml"

# Chilkat does not recommend trying to use binary MIME for email.
# Binary MIME is typically used in HTTP for uploads and downloads.
# 

# Also, binary MIME is not representable in a string.  
# If we try to get the MIME as a string, then it must be encoded
# using base64.

# Chilkat automatically changes binary encodings to base64
# when there's an attempt to get the MIME as a string.
set sb [new_CkStringBuilder]

CkEmail_GetMimeSb $email $sb
CkStringBuilder_WriteFile $sb "qa_output/email_fromSb.eml" "utf-8" 0

# Likewise, if we try to get the MIME as a string from the Mime object, 
# it cannot contain non-character data in a binary encoding.  The binary
# bytes MUST be in base64.  The act of trying to retrieve the MIME in string
# format will force Chilkat to convert binary encodings (for non-text parts)
# to base64.
CkMime_GetMimeSb $mime $sb
CkStringBuilder_WriteFile $sb "qa_output/mime_fromSb.eml" "utf-8" 0

# However, the above use of base64 is just for the purpose of making the MIME
# string friendly.  If we save the MIME to a file, it's still binary:
CkMime_SaveMime $mime "qa_output/mime_binary.mime"

delete_CkMime $mime
delete_CkBinData $binData
delete_CkEmail $email
delete_CkStringBuilder $sb