(PureBasic) 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.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkBinData.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkMime.pb"
IncludeFile "CkEmail.pb"

Procedure ChilkatExample()

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

    mime.i = CkMime::ckCreate()
    If mime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i

    CkMime::ckSetBodyFromPlainText(mime,"This is the plain text body.")
    CkMime::ckConvertToMultipartMixed(mime)
    CkMime::ckAppendPartFromFile(mime,"qa_data/jpg/penguins.jpg")
    CkMime::ckAppendPartFromFile(mime,"qa_data/pdf/fishing.pdf")

    ; At this point, when saved, the MIME bodies will be base64 encoded.
    CkMime::ckSaveMime(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.i = CkMime::ckGetPart(mime,1)
    CkMime::setCkEncoding(jpgPart, "binary")
    CkMime::ckDispose(jpgPart)

    pdfPart.i = CkMime::ckGetPart(mime,2)
    CkMime::setCkEncoding(pdfPart, "binary")
    CkMime::ckDispose(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::ckSaveMime(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?
    binData.i = CkBinData::ckCreate()
    If binData.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Write the binary MIME into binData;
    CkMime::ckGetMimeBd(mime,binData)

    email.i = CkEmail::ckCreate()
    If email.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Load the email from the binData.
    CkEmail::ckSetFromMimeBd(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::setCkSubject(email, "Binary MIME Email")
    CkEmail::setCkFrom(email, "admin@chilkatsoft.com")
    CkEmail::ckAddTo(email,"Chilkat","support@chilkatsoft.com")
    CkEmail::ckSaveEml(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.
    sb.i = CkStringBuilder::ckCreate()
    If sb.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkEmail::ckGetMimeSb(email,sb)
    CkStringBuilder::ckWriteFile(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::ckGetMimeSb(mime,sb)
    CkStringBuilder::ckWriteFile(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::ckSaveMime(mime,"qa_output/mime_binary.mime")


    CkMime::ckDispose(mime)
    CkBinData::ckDispose(binData)
    CkEmail::ckDispose(email)
    CkStringBuilder::ckDispose(sb)


    ProcedureReturn
EndProcedure