Mail::Message::Body::Nested(3)

NAME
Mail::Message::Body::Nested - body of a message which contains a message

INHERITANCE
 Mail::Message::Body::Nested
   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->isNested) {
     my $nest = $body->nested;
     $nest->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 a nested message, like "message/rfc822".

A nested message is different from a multipart message which contains only one element, because a nested message has a full set of message header fields defined by the RFC882, where a part of a multipart has only a few. But because we do not keep track whether all fields are presented, a "Mail::Message::Part" is used anyway.

WARNING: Since 2023, at least outlook started to interpret RFC6533 incorrectly. Bodies of type 'message/rfc822' can only be 'nested', but when they (illegally) have Content-Transfer-Encoding, they can now behave like normal message parts (the same as a pdf or image).

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
      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'
      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  'message/rfc822'
      modified           Mail::Message::Body  false
      nested                                  undef
      transfer_encoding  Mail::Message::Body  'none'

    based_on => $body
    charset => $charset|'PERL'|<undef>
    checked => BOOLEAN
    content_id => STRING
    data => \@lines|$text
    description => STRING|$field
    disposition => STRING|$field
    eol => 'CR'|'LF'|'CRLF'|'NATIVE'
    file => $file|$handle|$io
    filename => $file
    language => STRING|\@lang|$field
    message => $message
    mime_type => STRING|$field|$mime
    modified => BOOLEAN
    nested => $message
        The $message which is encapsulated within this body.

    transfer_encoding => STRING|$field

    » example:

      my $msg   = $folder->message(3);
      my $encaps= Mail::Message::Body::Nested->new(nested => $msg);

      # The body will be coerced into a message, which lacks a few
      # lines but we do not bother.
      my $intro = Mail::Message::Body->new(data => ...);
      my $body  = Mail::Message::Body::Nested->new(nested  => $intro);

  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, %options)
    Inherited, 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->foreachLine((CODE))
    It is NOT possible to call some code for each line of a nested because that would damage the header of the encapsulated message Improves base, see "Constructing a body" in Mail::Message::Body::Construct

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

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

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

$obj->forNested(CODE)
    Execute the "CODE" for the nested message. This returns a new nested body object. Returns "undef" when the "CODE" returns "undef".

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

$obj->nested()
    Returns the Mail::Message::Part message which is enclosed within this body.

$obj->print( [$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: 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 $class)
    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 line terminator '$eol'.
    Cast by eol()

Error: you cannot use foreachLine on a nested.
    foreachLine() should be used on decoded message bodies only, because it would modify the header of the encapsulated message. which is clearly not acceptable. Cast by foreachLine()

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.