Mail::Message::Body::Encode
Section: User Contributed Perl Documentation (3)
Updated: 2021-01-27
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NAME
Mail::Message::Body::Encode - organize general message encodings
SYNOPSIS
my Mail::Message $msg = ...;
my $decoded = $msg->decoded;
my $encoded = $msg->encode(mime_type => 'image/gif',
transfer_encoding => 'base64');
my $body = $msg->body;
my $decoded = $body->decoded;
my $encoded = $body->encode(transfer_encoding => '7bit');
DESCRIPTION
Manages the message's body encodings and decodings on request of the
main program. This package adds functionality to the Mail::Message::Body
class when the
decoded() or
encode() method is called.
Four types of encodings are handled (in the right order)
- •
-
eol encoding
Various operating systems have different ideas about how to encode the
line termination. UNIX uses a LF character, MacOS uses a CR, and
Windows uses a CR/LF combination. Messages which are transported over
Internet will always use the CRLF separator.
- •
-
transfer encoding
Messages transmitted over Internet have to be plain ASCII. Complicated
characters and binary files (like images and archives) must be encoded
during transmission to an ASCII representation.
The implementation of the required encoders and decoders is found in
the Mail::Message::TransferEnc set of packages. The related
manual page lists the transfer encodings which are supported.
- •
-
mime-type translation
NOT IMPLEMENTED YET
- •
-
charset conversion
METHODS
Constructing a body
- $obj->check()
-
Check the content of the body not to include illegal characters. Which
characters are considered illegal depends on the encoding of this body.
A body is returned which is checked. This may be the body where this
method is called upon, but also a new object, when serious changes had
to be made. If the check could not be made, because the decoder is not
defined, then "undef" is returned.
- $obj->encode(%options)
-
Encode (translate) a Mail::Message::Body into a different format.
See the DESCRIPTION above. Options which are not specified will not trigger
conversions.
-Option --Default
charset PERL if text
mime_type undef
result_type <same as source>
transfer_encoding undef
-
- charset => CODESET|'PERL'
-
If the CODESET is explicitly specified (for instance "iso-8859-10", then
the data is interpreted as raw bytes (blob), not as text. However, in
case of "PERL", it is considered to be an internal representation of
characters (either latin1 or Perl's utf8 --not the same as utf-8--, you should
not know).
- mime_type => STRING|FIELD
-
Convert into the specified mime type, which can be specified as STRING
or FIELD. The FIELD is a Mail::Message::Field, and the STRING is
converted in such object before use.
- result_type => CLASS
-
The type of body to be created when the body is changed to fulfill the request
on re-coding. Also the intermediate stages in the translation process (if
needed) will use this type. CLASS must extend Mail::Message::Body.
- transfer_encoding => STRING|FIELD
-
-
- $obj->encoded()
-
Encode the body to a format what is acceptable to transmit or write to
a folder file. This returns the body where this method was called
upon when everything was already prepared, or a new encoded body
otherwise. In either case, the body is checked.
- $obj->unify($body)
-
Unify the type of the given $body objects with the type of the called
body. "undef" is returned when unification is impossible. If the
bodies have the same settings, the $body object is returned unchanged.
Examples:
my $bodytype = Mail::Message::Body::Lines;
my $html = $bodytype->new(mime_type=>'text/html', data => []);
my $plain = $bodytype->new(mime_type=>'text/plain', ...);
my $unified = $html->unify($plain);
# $unified is the data of plain translated to html (if possible).
About the payload
- $obj->dispositionFilename( [$directory] )
-
Various fields are searched for "filename" and "name" attributes. Without
$directory, the name found will be returned unmodified.
When a $directory is given, a filename is composed. For security reasons,
only the basename of the found name gets used and many potentially
dangerous characters removed. If no name was found, or when the found
name is already in use, then an unique name is generated.
Don't forget to read RFC6266 section 4.3 for the security aspects in your
email application.
- $obj->isBinary()
-
Returns true when the un-encoded message is binary data. This information
is retrieved from knowledge provided by MIME::Types.
- $obj->isText()
-
Returns true when the un-encoded message contains printable
text.
Internals
- $obj->addTransferEncHandler( $name, <$class|$object> )
-
- Mail::Message::Body->addTransferEncHandler( $name, <$class|$object> )
-
Relate the NAMEd transfer encoding to an OBJECTs or object of the specified
$class. In the latter case, an object of that $class will be created on the
moment that one is needed to do encoding or decoding.
The $class or $object must extend Mail::Message::TransferEnc. It will
replace existing class and object for this $name.
Why aren't you contributing this class to MailBox?
- $obj->getTransferEncHandler($type)
-
Get the transfer encoder/decoder which is able to handle $type, or return
undef if there is no such handler.
DIAGNOSTICS
- Warning: Charset $name is not known
-
The encoding or decoding of a message body encounters a character set which
is not understood by Perl's Encode module.
- Warning: No decoder defined for transfer encoding $name.
-
The data (message body) is encoded in a way which is not currently understood,
therefore no decoding (or recoding) can take place.
- Warning: No encoder defined for transfer encoding $name.
-
The data (message body) has been decoded, but the required encoding is
unknown. The decoded data is returned.
SEE ALSO
This module is part of Mail-Message distribution version 3.010,
built on October 14, 2020. Website:
http://perl.overmeer.net/CPAN/
LICENSE
Copyrights 2001-2020 by [Mark Overmeer <
markov@cpan.org>]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See http://dev.perl.org/licenses/