man Mail::Message::Construct::Forward () - forwarding a Mail::Message

NAME

Mail::Message::Construct::Forward - forwarding a Mail::Message

SYNOPSIS

 my Mail::Message $forward = $message->forward(To => 'you');
 $forward->send;

DESCRIPTION

Complex functionality on Mail::Message objects is implemented in different files which are autoloaded. This file implements the functionality related to creating forwarded messages.

METHODS

Constructing a message

$obj->forward(OPTIONS) Forward the content of this message. The body of the message to be forwarded is encapsulated in some accompanying text (if you have no wish for that, than CWbounce is your choice). A Mail::Message object is returned on success. You may forward a whole message, but also message parts. You may wish to overrule some of the default header settings for the reply immediately, or you may do that later with CWset on the header. When a multi-part body is encountered, and the message is included to ATTACH, the parts which look like signatures will be removed. If only one message remains, it will be the added as single attachment, otherwise a nested multipart will be the result. The value of this option does not matter, as long as it is present. See CWMail::Message::Body::Multipart. 

 Option      Defined in       Default                                                                       
 Bcc                          undef                                                                         
 Cc                           undef                                                                         
 Date                         <now>                                                                         
 From                         <'to' in current>                                                             
 Message-ID                   <uniquely generated>                                                          
 Subject                      L<forwardSubject()|Mail::Message::Construct::Forward/"Constructing a message">
 To                           <required>                                                                    
 body                         undef                                                                         
 include                      <if body then C<'NO'> else C<'INLINE'>>                                       
 preamble                     C<constructed from prelude and postlude>                                      
 signature                    undef
. Bcc ADDRESSES Receivers of blind carbon copies: their names will not be published to other message receivers. . Cc ADDRESSES The carbon-copy receivers, by default none. . Date DATE The date to be used in the message sent. . From ADDRESSES Your identification, by default taken from the CWTo field of the source message. . Message-ID STRING Supply a STRING as specific message-id for the forwarded message. By default, one is generated for you. If there are no angles around your id, they will be added. . Subject STRING|CODE Force the subject line to the specific STRING, or the result of the subroutine specified by CODE. The subroutine will be called passing the subject of the original message as only argument. By default, the forwardSubject() method is used. . To ADDRESSES The destination of your message. Obligatory. The ADDRESSES may be specified as string, a Mail::Address object, or as array of Mail::Address objects. . body OBJECT If you specify a fully prepared body OBJECT, it will be used as forwarded message contents. In this case, only the headers are constructed for you. . include 'NO'|'INLINE'|'ATTACH'|'ENCAPSULATE' Must the message where this is a reply to be included in the message? When CWINLINE is given, you may pass the options of forwardInline() as well. In many applications, the forward option CWas attachment results in a structure which is produced when this option is set to CWENCAPSULATE. Their default behavior is usually CWINLINE. It is only possible to inline textual messages, therefore binary or multi-part messages will always be enclosed as attachment. Read the details in section Creating a forward.. . preamble STRING|BODY Part which is attached before the forwarded message. If no preamble is given, then it is constructed from the prelude and postlude. When these are also not present, you will still get a one liner: the result of forwardPrelude() . signature BODY|MESSAGE The signature to be added in case of a multi-part forward. The mime-type of the signature body should indicate this is a used as such. However, in INLINE mode, the body will be taken, a line containing CW'-- ' added before it, and added behind the epilogue.

$obj->forwardAttach(OPTIONS) Forward the message as flat attachment to the specified CWpreamble. You can specify all options available to CWforward(), although a CWpreamble which is provided as body object is required, and any specified CWbody is ignored. 

 Option    Defined in  Default   
 preamble              <required>
. preamble BODY|PART

$obj->forwardEncapsulate(OPTIONS) Like forwardAttach(), but in this case the original message is first encapsulated as nested message in a Mail::Message::Body::Nested, and then joint into a multipart. You can specify all options available to CWforward(), although a CWpreamble which is provided as body object is required, and any specified CWbody is ignored. Signatures are not stripped. Signatures are not stripped. 

 Option    Defined in  Default   
 preamble              <required>
. preamble BODY|PART

$obj->forwardInline(OPTIONS) This method is equivalent in behavior to forward() with the option CWinclude set to CW'INLINE'. You can specify most of the fields which are available to forward() except CWinclude and CWbody. 

 Option           Defined in       Default                                   
 is_attached                       C<"[The forwarded message is attached]\n">
 max_signature                     C<10>                                     
 postlude                          undef                                     
 prelude                           undef                                     
 quote                             undef                                     
 strip_signature                   C<qr/^--\s/>
. is_attached STRING A forward on binary messages can not be inlined. Therefore, they are automatically translated into an attachment, as made by forwardAttach(). The obligatory preamble option to that method may be specified as option to this method, to be used in case of such a forward of a binary, but is otherwise constructed from the prelude, the value of this option, and the postlude. . max_signature INTEGER Passed to Mail::Message::Body::stripSignature(max_lines). Only effective for single-part messages. . postlude BODY The line(s) which to be added after the quoted reply lines. Create a body for it first. This should not include the signature, which has its own option. The signature will be added after the postlude when the forwarded message is CWINLINEd. . prelude BODY The line(s) which will be added before the quoted forwarded lines. If nothing is specified, the result of the forwardPrelude() method is used. When CWundef is specified, no prelude will be added. . quote CODE|STRING Mangle the lines of an CWINLINEd reply with CODE, or by prepending a STRING to each line. The routine specified by CODE is called when the line is in CW$_. By default, nothing is added before each line. This option is processed after the body has been decoded. . strip_signature REGEXP|STRING|CODE Remove the signature of the sender. The value of this parameter is passed to Mail::Message::Body::stripSignature(pattern), unless the source text is not included. The signature is stripped from the message before quoting.

$obj->forwardNo(OPTIONS) Construct a forward, where the whole body of the message is already constructed. That complex body is usually produced in forwardInline(), forwardAttach(), or forwardEncapsulate(). The OPTIONS are the same as for CWforward() except that CWbody is required. Some other options, like CWpreamble, are ignored. 

 Option  Defined in  Default   
 body                <required>
. body BODY

$obj->forwardPostlude Added after the forwarded message. Example: 

 ---- END forwarded message

$obj->forwardPrelude Create a few lines to be included before the forwarded message content. The return is an array of lines. Example: 

 ---- BEGIN forwarded message
 From: him@somewhere.else.nl (Original Sender)
 To: me@example.com (Me the receiver)
 Cc: the.rest@world.net
 Date: Wed, 9 Feb 2000 15:44:05 -0500
 <blank line>

$obj->forwardSubject(STRING) Create a subject for a message which is a forward from this one. This routine tries to count the level of reply in subject field, and transform it into a standard form. Please contribute improvements. Example: 

 subject                 --> Forw: subject
 Re: subject             --> Forw: Re: subject
 Re[X]: subject          --> Forw: Re[X]: subject
 <blank>                 --> Forwarded

DIAGNOSTICS

Error: Cannot include forward source as CW$include.

Unknown alternative for the forward(include). Valid choices are CWNO, CWINLINE, CWATTACH, and CWENCAPSULATE.

Error: No address to create forwarded to.

If a forward message is created, a destination address must be specified.

Error: forwardAttach requires a preamble object

Error: forwardEncapsulate requires a preamble object

DETAILS

Creating a forward

The main difference between bounce() and forward() is the reason for message processing. The bounce has no intention to modify the content of message: the same information is passed-on to someplace else. This may mean some conversions, but for instance, the Message-ID does not need to be changed.

The purpose of forward() is to pass on information which is modified: annotated or reduced. The information is not sent back to the author of the original message (which is implemented by reply()), but to someone else.

So: some information comes in, is modified, and than forwarded to someone else. Currently, there are four ways to get the original information included, which are explained in the next sections.

After the creation of the forward, you may want to rebuild() the message to remove unnecessary complexities. Of course, that is not required.

forward, specify a body

When you specify forward(body), you have created your own body object to be used as content of the forwarded message. This implies that forward(include) is CW'NO': no automatic generation of the forwarded body.

forward, inline the original

The forward(include) is set to CW'INLINE' (the default) This is the most complicated situation, but most often used by MUAs: the original message is inserted textually in the new body. You can set-up automatic stripping of signatures, the way of encapsulation, and texts which should be added before and after the encapsulated part.

However, the result may not always be what you expect. For instance, some people use very long signatures which will not be automatically stripped because the pass the threshold. So, you probably need some manual intervention after the message is created and before it is sent.

When a binary message is encountered, inlining is impossible. In that case, the message is treated as if CW'ENCAPSULATE' was requested.

forward, attach the original

When forward(include) is explicitly set to CW'ATTACH' the result will be a multipart which contains two parts. The first part will be your message, and the second the body of the original message.

This means that the headers of the forwarded message are used for the new message, and detached from the part which now contains the original body information. Content related headers will (of course) still be part of that part, but lines line CWTo and CWSubject will not be stored with that part.

As example of the structural transformation: 

 # code: $original->printStructure;
 multipart/alternative: The source message
   text/plain: content in raw text
   text/html: content as html


 # code: $fwd = $original->forward(include => 'ATTACH');
 # code: $fwd->printStructure
 multipart/mixed: The source message
   text/plain: prelude/postlude/signature
   multipart/alternative
     text/plain: content in raw text
     text/html: content as html

forward, encapsulate the original

When forward(include) is explicitly set to CW'ENCAPSULATE', then the original message is left in-tact as good as possible. The lines of the original message are used in the main message header but also enclosed in the part header.

The encapsulation is implemented using a nested message, content type CWmessage/rfc822. As example of the structural transformation: 

 # code: $original->printStructure;
 multipart/alternative: The source message
   text/plain: content in raw text
   text/html: content as html


 # code: $fwd = $original->forward(include => 'ENCAPSULATE');
 # code: $fwd->printStructure
 multipart/mixed: The source message
   text/plain: prelude/postlude/signature
   message/rfc822
      multipart/alternative: The source message
         text/plain: content in raw text
         text/html: content as html

The message structure is much more complex, but no information is lost. This is probably the reason why many MUAs use this when the forward an original message as attachment.

REFERENCES

See the MailBox website at <http://perl.overmeer.net/mailbox/> for more details.

COPYRIGHTS

Distribution version 2.063. Written by Mark Overmeer (mark@overmeer.net). See the ChangeLog for other contributors.

Copyright (c) 2001-2003 by the author(s). All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.