Mail::Message::Body::Multipart(3)

NAME
Mail::Message::Body::Multipart - body of a message with attachments

INHERITANCE
 Mail::Message::Body::Multipart
   is a Mail::Message::Body
   is a Mail::Reporter

   Mail::Message::Body also extends Mail::Reporter
   is a Mail::Reporter

SYNOPSIS
  See Mail::Message::Body

  if($body->isMultipart) {
     my @attachments = $body->parts;
     my $attachment3 = $body->part(2);
     my $before      = $body->preamble;
     my $after       = $body->epilogue;
     $body->part(1)->delete;
  }

DESCRIPTION
The body (content) of a message can be stored in various ways. In this manual-page you find the description of extra functionality you have when a message contains attachments (parts).

The number of multipart alternatives is growing. A full list is maintained by IANA af <https://www.iana.org/assignments/media-types/media-types.xhtml#multipart>

•   multipart/mixed

•   multipart/alternative

•   multipart/related

•   multipart/report, RFC6522

•   multipart/signed, RFC1847

•   multipart/encrypted

•   multipart/multilingual, RFC8255 (unused)

Extends "DESCRIPTION" in Mail::Message::Body.

OVERLOADED
Extends "OVERLOADED" in Mail::Message::Body.

overload: "" stringification
    Inherited, see "OVERLOADED" in Mail::Message::Body

overload: '==' numerical comparison
    Inherited, see "OVERLOADED" in Mail::Message::Body

overload: @{} addressed as array
    Inherited, see "OVERLOADED" in Mail::Message::Body

overload: bool true/false
    Inherited, see "OVERLOADED" in Mail::Message::Body

METHODS
Extends "METHODS" in Mail::Message::Body.

  Constructors
Extends "Constructors" in Mail::Message::Body.

$obj->clone()
    Inherited, see "Constructors" in Mail::Message::Body

$class->new(%options)
    Inherited, see "Constructors" in Mail::Message::Body

     -Option           --Defined in         --Default
      based_on           Mail::Message::Body  undef
      boundary                                undef
      charset            Mail::Message::Body  'PERL'
      checked            Mail::Message::Body  false
      content_id         Mail::Message::Body  undef
      data               Mail::Message::Body  undef
      description        Mail::Message::Body  undef
      disposition        Mail::Message::Body  undef
      eol                Mail::Message::Body  'NATIVE'
      epilogue                                ''
      file               Mail::Message::Body  undef
      filename           Mail::Message::Body  undef
      language           Mail::Message::Body  undef
      message            Mail::Message::Body  undef
      mime_type          Mail::Message::Body  'multipart/mixed'
      modified           Mail::Message::Body  false
      parts                                   undef
      preamble                                undef
      transfer_encoding  Mail::Message::Body  'none'

    based_on => $body
    boundary => $separator
        The $separator string to be used between parts of the message. This separator must be unique in case the message contains nested multiparts (which are not unusual). If "undef", a nice unique boundary will be generated.

    charset => $charset|'PERL'|<undef>
    checked => BOOLEAN
    content_id => STRING
    data => \@lines|$text
    description => STRING|$field
    disposition => STRING|$field
    eol => 'CR'|'LF'|'CRLF'|'NATIVE'
    epilogue => $body|$text
        The text which is included in the main body after the final boundary. This is usually empty, and has no meaning.

        Provide a $body object or plain $text (which will automatically translated into a "text/plain" body).

    file => $file|$handle|$io
    filename => $file
    language => STRING|\@lang|$field
    message => $message
    mime_type => STRING|$field|$mime
    modified => BOOLEAN
    parts => [$message, $body, ...]
        Specifies an initial list of parts in this body. These may be full $message objects, or $body objects which will be transformed into messages before use. Each message is coerced into a Mail::Message::Part object.

        MIME::Entity and Mail::Internet objects are acceptable in the list, because they are coercible into Mail::Message::Part's. Values of "undef" will be skipped silently.

    preamble => $body|$text
        The $text which is included in the body before the first part. It is common use to include a text to warn the user that the message is a multipart. However, this was useful in earlier days: most mail agents are very capable in warning the user themselves.

        Provide a $body object or plain $text (which will automatically translated into a "text/plain" body).

    transfer_encoding => STRING|$field

    » example:

      my $intro = Mail::Message::Body->new(data => ['part one']);
      my $pgp   = Mail::Message::Body->new(data => ['part three']);

      my $body  = Mail::Message::Body::Multipart->new(
        boundary => time . '--it-s-mine',
        preamble => "This is a multi-part message in MIME format.\n\n",
        parts    => [ $intro, $folder->message(3)->decoded, $pgp ],
      );

  Attributes
Extends "Attributes" in Mail::Message::Body.

$obj->charsetDetectAlgorithm( [CODE|undef|METHOD] )
    Inherited, see "Attributes" in Mail::Message::Body::Encode

  Constructing a body
Extends "Constructing a body" in Mail::Message::Body.

$obj->attach($messages|$bodies)
    Attach a list of $messages to this multipart. A new body is returned. When you specify $bodies, they will first be translated into real messages. MIME::Entity and Mail::Internet objects may be specified too. In any case, the parts will be coerced into Mail::Message::Part's. Improves base, see "Constructing a body" in Mail::Message::Body::Construct

$obj->charsetDetect(%options)
    Inherited, see "Constructing a body" in Mail::Message::Body::Encode

$obj->check()
    Inherited, see "Constructing a body" in Mail::Message::Body::Encode

$obj->concatenate(@components)
    Inherited, see "Constructing a body" in Mail::Message::Body::Construct

$obj->decoded(%options)
    Inherited, see "Constructing a body" in Mail::Message::Body

$obj->encode(%options)
    Inherited, see "Constructing a body" in Mail::Message::Body::Encode

$obj->encoded(%options)
    Inherited, see "Constructing a body" in Mail::Message::Body::Encode

$obj->eol( ['CR'|'LF'|'CRLF'|'NATIVE'] )
    Inherited, see "Constructing a body" in Mail::Message::Body::Encode

$obj->foreachComponent(CODE)
    Execute the "CODE" for each component of the message: the preamble, the epilogue, and each of the parts.

    Each component is a body and is passed as second argument to the "CODE". The first argument is a reference to this multi-parted body. The "CODE" returns a body object. When any of the returned bodies differs from the body which was passed, then a new multi-part body will be returned. Reference to the not-changed bodies and the changed bodies will be included in that new multi-part.

    » example:

      my $checked = $multi->foreachComponent(sub {$_[1]->check});

$obj->foreachLine((CODE))
    It is NOT possible to call some code for each line of a multipart, because that would not only inflict damage to the body of each message part, but also to the headers and the part separators. Improves base, see "Constructing a body" in Mail::Message::Body::Construct

$obj->stripSignature(%options)
    Removes all parts which contains data usually defined as being signature. The MIME::Type module provides this knowledge. A new multipart is returned, containing the remaining parts. No %options are defined yet, although some may be specified, because this method overrules the "stripSignature" method for normal bodies. Improves base, see "Constructing a body" in Mail::Message::Body::Construct

     -Option     --Defined in                    --Default
      max_lines    Mail::Message::Body::Construct  10
      pattern      Mail::Message::Body::Construct  qr/^--\s?$/
      result_type  Mail::Message::Body::Construct  <same as current>

    max_lines => INTEGER|undef
    pattern => REGEX|STRING|CODE
    result_type => CLASS

$obj->unify($body)
    Inherited, see "Constructing a body" in Mail::Message::Body::Encode

  The body
Extends "The body" in Mail::Message::Body.

$obj->isDelayed()
    Inherited, see "The body" in Mail::Message::Body

$obj->isMultipart()
    Inherited, see "The body" in Mail::Message::Body

$obj->isNested()
    Inherited, see "The body" in Mail::Message::Body

$obj->message( [$message] )
    Inherited, see "The body" in Mail::Message::Body

$obj->partNumberOf($part)
    Inherited, see "The body" in Mail::Message::Body

  About the payload
Extends "About the payload" in Mail::Message::Body.

$obj->charset()
    Inherited, see "About the payload" in Mail::Message::Body

$obj->checked( [BOOLEAN] )
    Inherited, see "About the payload" in Mail::Message::Body

$obj->contentId( [STRING|$field] )
    Inherited, see "About the payload" in Mail::Message::Body

$obj->description( [STRING|$field] )
    Inherited, see "About the payload" in Mail::Message::Body

$obj->disposition( [STRING|$field] )
    Inherited, see "About the payload" in Mail::Message::Body

$obj->dispositionFilename( [$directory] )
    Inherited, see "About the payload" in Mail::Message::Body::Encode

$obj->isBinary()
    Inherited, see "About the payload" in Mail::Message::Body::Encode

$obj->isText()
    Inherited, see "About the payload" in Mail::Message::Body::Encode

$obj->language( [@langs|\@langs|$langs|$field] )
    Inherited, see "About the payload" in Mail::Message::Body

$obj->mimeType()
    Inherited, see "About the payload" in Mail::Message::Body

$obj->nrLines()
    Inherited, see "About the payload" in Mail::Message::Body

$obj->size()
    Inherited, see "About the payload" in Mail::Message::Body

$obj->transferEncoding( [STRING|$field] )
    Inherited, see "About the payload" in Mail::Message::Body

$obj->type( [STRING|$field] )
    Inherited, see "About the payload" in Mail::Message::Body

  Access to the payload
Extends "Access to the payload" in Mail::Message::Body.

$obj->boundary( [STRING] )
    Returns the boundary which is used to separate the parts in this body. If none was read from file, then one will be assigned. With "STRING" you explicitly set the boundary to be used.

$obj->endsOnNewline()
    Inherited, see "Access to the payload" in Mail::Message::Body

$obj->epilogue()
    Returns the epilogue; the text after the last message part (after the last real attachment). The epilogue is stored in a BODY object, and its encoding is taken from the general multipart header.

$obj->file()
    Inherited, see "Access to the payload" in Mail::Message::Body

$obj->lines()
    Inherited, see "Access to the payload" in Mail::Message::Body

$obj->part($index)
    Returns only the part with the specified $index. You may use a negative value here, which counts from the back in the list. Parts which are flagged to be deleted are included in the count.

    » example:

      $message->body->part(2)->print;
      $body->part(1)->delete;

$obj->parts( [<'ALL'|'ACTIVE'|'DELETED'|'RECURSE'|$filter>] )
    Return all parts by default, or when "ALL" is specified. "ACTIVE" returns the parts which are not flagged for deletion, as opposite to "DELETED". "RECURSE" descents into all nested multiparts to collect all parts.

    You may also specify a code reference which is called for each nested part. The first argument will be the message part. When the code returns "true", the part is incorporated in the return list.

    » example:

      print "Number of attachments: ",
         scalar $message->body->parts('ACTIVE');

      foreach my $part ($message->body->parts) {
         print "Type: ", $part->get('Content-Type');
      }

$obj->preamble()
    Returns the preamble; the text before the first message part (before the first real attachment). The preamble is stored in a BODY object, and its encoding is taken from the multipart header.

$obj->print( [$fh] )
    Inherited, see "Access to the payload" in Mail::Message::Body

$obj->printEscapedFrom($fh)
    Inherited, see "Access to the payload" in Mail::Message::Body

$obj->string()
    Inherited, see "Access to the payload" in Mail::Message::Body

$obj->stripTrailingNewline()
    Inherited, see "Access to the payload" in Mail::Message::Body

$obj->write(%options)
    Inherited, see "Access to the payload" in Mail::Message::Body

  Internals
Extends "Internals" in Mail::Message::Body.

$any->addTransferEncHandler( $name, <$class|$object> )
    Inherited, see "Internals" in Mail::Message::Body::Encode

$obj->contentInfoFrom($head)
    Inherited, see "Internals" in Mail::Message::Body

$obj->contentInfoTo($head)
    Inherited, see "Internals" in Mail::Message::Body

$obj->fileLocation( [$begin, $end] )
    Inherited, see "Internals" in Mail::Message::Body

$obj->getTransferEncHandler($type)
    Inherited, see "Internals" in Mail::Message::Body::Encode

$obj->isModified()
    Inherited, see "Internals" in Mail::Message::Body

$obj->load()
    Inherited, see "Internals" in Mail::Message::Body

$obj->modified( [BOOLEAN] )
    Inherited, see "Internals" in Mail::Message::Body

$obj->moveLocation( [$distance] )
    Inherited, see "Internals" in Mail::Message::Body

$obj->read( $parser, $head, $bodytype, [$chars, [$lines]] )
    Inherited, see "Internals" in Mail::Message::Body

  Error handling
Extends "Error handling" in Mail::Message::Body.

$obj->AUTOLOAD()
    Inherited, see "Error handling" in Mail::Message::Body

$obj->notImplemented()
    Inherited, see "Error handling" in Mail::Reporter

$obj->notImplemented()
    Inherited, see "Error handling" in Mail::Reporter

  Cleanup
Extends "Cleanup" in Mail::Message::Body.

$obj->DESTROY()
    Inherited, see "Cleanup" in Mail::Reporter

$obj->DESTROY()
    Inherited, see "Cleanup" in Mail::Reporter

DETAILS
Extends "DETAILS" in Mail::Message::Body.

DIAGNOSTICS

Warning: Content-Transfer-Encoding '$te' requires explicit charset, defaulted to utf-8.
    Cast by encode()

Error: You cannot use foreachLine on a multipart.
    foreachLine() should be used on decoded message bodies only, because it would attempt to modify part-headers and separators as well, which is clearly not acceptable. Cast by foreachLine()

Error: cannot concatenate element $which
    Cast by concatenate()

Fault: cannot open $file to write body: $!
    Cast by write()

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. Cast by encode()

Error: class $package does not implement method $method.
    Fatal error: the specific $package (or one of its superclasses) does not implement this method where it should. This message means that some other related classes do implement this method however the class at hand does not. Probably you should investigate this and probably inform the author of the package. Cast by notImplemented()

Error: class $package does not implement method $method.
    Fatal error: the specific $package (or one of its superclasses) does not implement this method where it should. This message means that some other related classes do implement this method however the class at hand does not. Probably you should investigate this and probably inform the author of the package. Cast by notImplemented()

Error: data not convertible to a message (type is $type)
    An object which is not coercable into a Mail::Message::Part object was passed to the initiation. Cast by new()

Fault: error closing $file after write body: $!
    Cast by write()

Warning: no decoder defined for transfer encoding '$encoding'.
    The data (message body) is encoded in a way which is not currently understood, therefore no decoding (or recoding) can take place. Cast by encode()

Warning: no encoder defined for transfer encoding '$encoding'.
    The data (message body) has been decoded, but the required encoding is unknown. The decoded data is returned. Cast by encode()

Error: no filename parameter for write() body.
    Cast by write()

Error: part number needs multi-part or nested.
    Cast by partNumberOf()

Error: unknown criterium $what to select parts.
    Valid choices for part selections are "ALL", "ACTIVE", "DELETED", "RECURSE" or a code reference. However, some other argument was passed. Cast by parts()

Error: unknown line terminator '$eol'.
    Cast by eol()

SEE ALSO
This module is part of Mail-Message version 4.01, built on December 13, 2025. Website: http://perl.overmeer.net/CPAN/

LICENSE
For contributors see file ChangeLog.

This software is copyright (c) 2001-2025 by Mark Overmeer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.