77 lines
3.6 KiB
TeX
77 lines
3.6 KiB
TeX
\declaremodule{standard}{email.Generator}
|
|
\modulesynopsis{Generate flat text email messages from a message object tree.}
|
|
|
|
One of the most common tasks is to generate the flat text of the email
|
|
message represented by a message object tree. You will need to do
|
|
this if you want to send your message via the \refmodule{smtplib}
|
|
module or the \refmodule{nntplib} module, or print the message on the
|
|
console. Taking a message object tree and producing a flat text
|
|
document is the job of the \class{Generator} class.
|
|
|
|
Again, as with the \refmodule{email.Parser} module, you aren't limited
|
|
to the functionality of the bundled generator; you could write one
|
|
from scratch yourself. However the bundled generator knows how to
|
|
generate most email in a standards-compliant way, should handle MIME
|
|
and non-MIME email messages just fine, and is designed so that the
|
|
transformation from flat text, to an object tree via the
|
|
\class{Parser} class,
|
|
and back to flat text, is idempotent (the input is identical to the
|
|
output).
|
|
|
|
Here are the public methods of the \class{Generator} class:
|
|
|
|
\begin{classdesc}{Generator}{outfp\optional{, mangle_from_\optional{,
|
|
maxheaderlen}}}
|
|
The constructor for the \class{Generator} class takes a file-like
|
|
object called \var{outfp} for an argument. \var{outfp} must support
|
|
the \method{write()} method and be usable as the output file in a
|
|
Python 2.0 extended print statement.
|
|
|
|
Optional \var{mangle_from_} is a flag that, when true, puts a \samp{>}
|
|
character in front of any line in the body that starts exactly as
|
|
\samp{From } (i.e. \code{From} followed by a space at the front of the
|
|
line). This is the only guaranteed portable way to avoid having such
|
|
lines be mistaken for \emph{Unix-From} headers (see
|
|
\ulink{WHY THE CONTENT-LENGTH FORMAT IS BAD}
|
|
{http://home.netscape.com/eng/mozilla/2.0/relnotes/demo/content-length.html}
|
|
for details).
|
|
|
|
Optional \var{maxheaderlen} specifies the longest length for a
|
|
non-continued header. When a header line is longer than
|
|
\var{maxheaderlen} (in characters, with tabs expanded to 8 spaces),
|
|
the header will be broken on semicolons and continued as per
|
|
\rfc{2822}. If no semicolon is found, then the header is left alone.
|
|
Set to zero to disable wrapping headers. Default is 78, as
|
|
recommended (but not required) by \rfc{2822}.
|
|
\end{classdesc}
|
|
|
|
The other public \class{Generator} methods are:
|
|
|
|
\begin{methoddesc}[Generator]{__call__}{msg\optional{, unixfrom}}
|
|
Print the textual representation of the message object tree rooted at
|
|
\var{msg} to the output file specified when the \class{Generator}
|
|
instance was created. Sub-objects are visited depth-first and the
|
|
resulting text will be properly MIME encoded.
|
|
|
|
Optional \var{unixfrom} is a flag that forces the printing of the
|
|
\emph{Unix-From} (a.k.a. envelope header or \code{From_} header)
|
|
delimiter before the first \rfc{2822} header of the root message
|
|
object. If the root object has no \emph{Unix-From} header, a standard
|
|
one is crafted. By default, this is set to 0 to inhibit the printing
|
|
of the \emph{Unix-From} delimiter.
|
|
|
|
Note that for sub-objects, no \emph{Unix-From} header is ever printed.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Generator]{write}{s}
|
|
Write the string \var{s} to the underlying file object,
|
|
i.e. \var{outfp} passed to \class{Generator}'s constructor. This
|
|
provides just enough file-like API for \class{Generator} instances to
|
|
be used in extended print statements.
|
|
\end{methoddesc}
|
|
|
|
As a convenience, see the methods \method{Message.as_string()} and
|
|
\code{str(aMessage)}, a.k.a. \method{Message.__str__()}, which
|
|
simplify the generation of a formatted string representation of a
|
|
message object. For more detail, see \refmodule{email.Message}.
|