Tcl

Get the Nth Binary Part of a Content-Type into BinData

Demonstrates the Chilkat Email.GetNthBinaryPartOfTypeBd method, which loads the binary bytes of the Nth MIME sub-part matching a content-type pattern into a BinData object. The arguments are the zero-based index among the matching parts, the content-type pattern, an inlineOnly flag, an excludeAttachments flag, and the BinData that receives the bytes. This example extracts the first image/png part.

Background: This is the binary, type-targeted way to pull a specific part out of a message — ideal for extracting, say, every image/png or the one application/pdf from a complex MIME tree without caring whether it is an attachment, an inline image, or a body part. Reading into a BinData keeps the raw bytes exact, ready to save, hash, or re-transmit.

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Tcl


load ./chilkat.dll

set success 0

#  Demonstrates the GetNthBinaryPartOfTypeBd method, which loads the binary bytes of the Nth
#  MIME sub-part matching a Content-Type pattern into a BinData object.  The arguments are
#  the zero-based index among matching parts, the Content-Type pattern, inlineOnly,
#  excludeAttachments, and the BinData that receives the bytes.

set email [new_CkEmail]

CkEmail_put_Subject $email "GetNthBinaryPartOfTypeBd example"
CkEmail_put_Body $email "See the attached image."

#  Load the image from a file into a BinData object and attach it (binary data belongs
#  in a BinData, never in a string).
set bdImage [new_CkBinData]

set success [CkBinData_LoadFile $bdImage "qa_data/images/photo.png"]
if {$success == 0} then {
    puts [CkBinData_lastErrorText $bdImage]
    delete_CkEmail $email
    delete_CkBinData $bdImage
    exit
}

set success [CkEmail_AddAttachmentBd $email "photo.png" $bdImage "image/png"]
if {$success == 0} then {
    puts [CkEmail_lastErrorText $email]
    delete_CkEmail $email
    delete_CkBinData $bdImage
    exit
}

#  Load the bytes of the first (index 0) image/png part into a BinData object.
set bd [new_CkBinData]

set success [CkEmail_GetNthBinaryPartOfTypeBd $email 0 "image/png" 0 0 $bd]
if {$success == 0} then {
    puts [CkEmail_lastErrorText $email]
    delete_CkEmail $email
    delete_CkBinData $bdImage
    delete_CkBinData $bd
    exit
}

puts "image/png part size (bytes) = [CkBinData_get_NumBytes $bd]"

#  Note: The path "qa_data/images/photo.png" is a relative local filesystem path,
#  relative to the current working directory of the running application.

delete_CkEmail $email
delete_CkBinData $bdImage
delete_CkBinData $bd