Tcl

Get the Number of Body Alternatives in an Email

Demonstrates the read-only Chilkat Email.NumAlternatives property, which is the number of body representations present in the email. A representation may be plain text, HTML, iCalendar, or another body format. A normal email with one body returns 1, while a multipart/alternative email returns the number of alternatives it contains. Alternative indexes used by methods such as GetAlternativeBody are zero-based. This example builds an email with plain-text and HTML alternatives and prints the count.

Background: MIME organizes a message as a tree of parts. multipart/alternative holds several versions of the same content (the client shows the best one it supports); multipart/mixed combines a body with attachments; and multipart/related bundles an HTML body with the inline images it references. A rich email nests these, for example:

multipart/mixed
  multipart/alternative
    text/plain
    multipart/related
      text/html
      image/png
  application/pdf

Here the text/plain part and the multipart/related part are the two alternatives.

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Tcl


load ./chilkat.dll

#  Demonstrates the read-only Email.NumAlternatives property, which is the
#  number of body representations (plain text, HTML, iCalendar, etc.) in the email.

set email [new_CkEmail]

#  Set a plain-text body and add an HTML alternative.  This creates a
#  multipart/alternative email with two representations.
CkEmail_SetTextBody $email "This is the plain-text alternative." "text/plain"
CkEmail_AddHtmlAlternativeBody $email "<html><body><b>This is the HTML alternative.</b></body></html>"

#  Alternative indexes (used by GetAlternativeBody) are zero-based.
puts "NumAlternatives = [CkEmail_get_NumAlternatives $email]"

delete_CkEmail $email