=encoding utf8

=head1 NAME

Mail::Message::Body::Construct - adds functionality to Mail::Message::Body

=head1 SYNOPSIS

=head1 DESCRIPTION

This package adds complex functionality to the L<Mail::Message::Body|Mail::Message::Body>
class.  This functions less often used, so many programs will not
compile this package.

=head1 METHODS

=head2 Constructing a body

=over 4

=item $obj-E<gt>B<attach>(@messages, %options)

Make a multipart containing this body and the specified C<@messages>. The
options are passed to the constructor of the multi-part body.  If you
need more control, create the multi-part body yourself.  At least
take a look at L<Mail::Message::Body::Multipart|Mail::Message::Body::Multipart>.

The message-parts will be coerced into a L<Mail::Message::Part|Mail::Message::Part>, so you
may attach L<Mail::Internet|Mail::Internet> or MIME::Entity objects if you want --see
L<Mail::Message::coerce()|Mail::Message/"Internals">.  A new body with attached messages is
returned.

» example: 

  my $pgpkey = Mail::Message::Body::File->new(file => 'a.pgp');
  my $msg    = Mail::Message->buildFromBody($message->decoded->attach($pgpkey));

  # The last message of the $multi multiparted body becomes a coerced $entity.
  my $entity  = MIME::Entity->new;
  my $multi   = $msg->body->attach($entity);

  # Now create a new message
  my $msg     = Mail::Message->new(head => ..., body => $multi);

=item $obj-E<gt>B<concatenate>(@components)

Concatenate the textual content of a LIST of elements into one new body.
The resulting body object is based on the callee, which may itself not
be included in the result.

Specify a list of text C<@components>.  Each component can be

=over 4

=item * a message (L<Mail::Message|Mail::Message>, the body of the message is used),

=item * a plain body (L<Mail::Message::Body|Mail::Message::Body>),

=item * C<undef> (which will be skipped),

=item * a scalar (which is split into lines), or

=item * an array of scalars (each providing one line).

=back

» example: 

  # all arguments are Mail::Message::Body's.
  my $sum = $body->concatenate($preamble, $body, $epilogue, "-- \n" , $sig);

=item $obj-E<gt>B<foreachLine>(CODE)

Create a new body by performing an action on each of its lines.  If none
of the lines change, the current body will be returned, otherwise a new
body is created of the same type as the current.

The C<CODE> refers to a subroutine which is called, where C<$_> contains
body's original line.  DO NOT CHANGE C<$_>!!!  The result of the routine
is taken as new line.  When the routine returns C<undef>, the line will be
skipped.

» example: 

  my $content  = $msg->decoded;
  my $reply    = $content->foreachLine( sub { '> '.$_ } );
  my $rev      = $content->foreachLine( sub { reverse } );

  sub filled() { length $_ > 1 ? $_ : undef }
  my $nonempty = $content->foreachLine( \&filled );

  my $WRONG    = $content->foreachLine( sub { s/a/A/ } );
  my $right    = $content->foreachLine( sub { s/a/A/r });

=item $obj-E<gt>B<stripSignature>(%options)

Strip the signature from the body.  The body must already be decoded
otherwise the wrong lines may get stripped.  Returned is the stripped
version body, and in list context also the signature, encapsulated in
its own body object.  The signature separator is the first line of the
returned signature body.

The signature is added by the sender to tell about him- or herself.
It is superfluous in some situations, for instance if you want to create
a reply to the person's message you do not need to include that signature.

If the body had no signature, the original body object is returned,
and C<undef> for the signature body.

 -Option     --Default
  max_lines    10
  pattern      qr/^--\s?$/
  result_type  <same as current>

=over 2

=item max_lines => INTEGER|undef

The maximum number of lines which can be the length of a signature.
Specify C<undef> to remove the limit.

=item pattern => REGEX|STRING|CODE

Which pattern defines the line which indicates the separator between
the message and the signature.  In case of a STRING, this is matched
to the beginning of the line, and REGEX is a full regular expression.

In case of CODE, each line (from last to front) is passed to the
specified subroutine as first argument.  The subroutine must return
TRUE when the separator is found.

=item result_type => CLASS

The type of body to be created for the stripped body (and maybe also to
contain the stripped signature)

=back

» example: 

  my $start = $message->decoded;
  my $start = $body->decoded;

  my $stripped = $start->stripSignature;

  my ($stripped, $sign) = $start->stripSignature
      (max_lines => 5, pattern => '-*-*-');

=back

=head1 DIAGNOSTICS

=over 4

=item Error: cannot concatenate element $which

Cast by C<concatenate()>

=back

=head1 SEE ALSO

This module is part of Mail-Message version 4.03,
built on January 26, 2026. Website: F<http://perl.overmeer.net/CPAN/>

=head1 LICENSE

For contributors see file ChangeLog.

This software is copyright (c) 2001-2026 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.

