Doc/lib/libmimewriter.tex

   1 \section{\module{MimeWriter} ---
   2          Generic MIME file writer}
   3
   4 \declaremodule{standard}{MimeWriter}
   5
   6 \modulesynopsis{Generic MIME file writer.}
   7 \sectionauthor{Christopher G. Petrilli}{petrilli@amber.org}
   8
   9 This module defines the class \class{MimeWriter}.  The
  10 \class{MimeWriter} class implements a basic formatter for creating
  11 MIME multi-part files.  It doesn't seek around the output file nor
  12 does it use large amounts of buffer space. You must write the parts
  13 out in the order that they should occur in the final
  14 file. \class{MimeWriter} does buffer the headers you add, allowing you
  15 to rearrange their order.
  16
  17 \begin{classdesc}{MimeWriter}{fp}
  18 Return a new instance of the \class{MimeWriter} class.  The only
  19 argument passed, \var{fp}, is a file object to be used for
  20 writing. Note that a \class{StringIO} object could also be used.
  21 \end{classdesc}
  22
  23
  24 \subsection{MimeWriter Objects \label{MimeWriter-objects}}
  25
  26
  27 \class{MimeWriter} instances have the following methods:
  28
  29 \begin{methoddesc}{addheader}{key, value\optional{, prefix}}
  30 Add a header line to the MIME message. The \var{key} is the name of
  31 the header, where the \var{value} obviously provides the value of the
  32 header. The optional argument \var{prefix} determines where the header
  33 is inserted; \samp{0} means append at the end, \samp{1} is insert at
  34 the start. The default is to append.
  35 \end{methoddesc}
  36
  37 \begin{methoddesc}{flushheaders}{}
  38 Causes all headers accumulated so far to be written out (and
  39 forgotten). This is useful if you don't need a body part at all,
  40 e.g.\ for a subpart of type \mimetype{message/rfc822} that's (mis)used
  41 to store some header-like information.
  42 \end{methoddesc}
  43
  44 \begin{methoddesc}{startbody}{ctype\optional{, plist\optional{, prefix}}}
  45 Returns a file-like object which can be used to write to the
  46 body of the message.  The content-type is set to the provided
  47 \var{ctype}, and the optional parameter \var{plist} provides
  48 additional parameters for the content-type declaration. \var{prefix}
  49 functions as in \method{addheader()} except that the default is to
  50 insert at the start.
  51 \end{methoddesc}
  52
  53 \begin{methoddesc}{startmultipartbody}{subtype\optional{,
  54                    boundary\optional{, plist\optional{, prefix}}}}
  55 Returns a file-like object which can be used to write to the
  56 body of the message.  Additionally, this method initializes the
  57 multi-part code, where \var{subtype} provides the multipart subtype,
  58 \var{boundary} may provide a user-defined boundary specification, and
  59 \var{plist} provides optional parameters for the subtype.
  60 \var{prefix} functions as in \method{startbody()}.  Subparts should be
  61 created using \method{nextpart()}.
  62 \end{methoddesc}
  63
  64 \begin{methoddesc}{nextpart}{}
  65 Returns a new instance of \class{MimeWriter} which represents an
  66 individual part in a multipart message.  This may be used to write the
  67 part as well as used for creating recursively complex multipart
  68 messages. The message must first be initialized with
  69 \method{startmultipartbody()} before using \method{nextpart()}.
  70 \end{methoddesc}
  71
  72 \begin{methoddesc}{lastpart}{}
  73 This is used to designate the last part of a multipart message, and
  74 should \emph{always} be used when writing multipart messages.
  75 \end{methoddesc}