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] )
           Returns the name which can be used as filename to store the information in the
           indicated $directory. To get a filename, various fields are searched for "filename"
           and "name" attributes.  Without $directory, the name found will be returned.

           Only the basename of the found name will be used, for security reasons: otherwise, it
           may be possible to access other directories than the one indicated.  If no name was
           found, or the name is already in use, then an unique name is generated.

       $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 3.006, built on January 24, 2018.
       Website: http://perl.overmeer.net/CPAN/

LICENSE

       Copyrights 2001-2018 by [Mark Overmeer]. 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/