NAME

Mail::Message::Field - one line of a message header

CLASS HIERARCHY

 Mail::Message::Field
 is a Mail::Reporter

SYNOPSIS

 my $field = Mail::Message::Field->new(From => 'me@example.com');
 print $field->name;
 print $field->body;
 print $field->comment;
 $field->print(\*OUT);
 print $field->toString;
 print "$field\n";
 print $field->attribute('charset') || 'us-ascii';

DESCRIPTION

These objects each store one header line, and facilitates access routines to the information hidden in it. Also, you may want to have a look at the added methods of a message:

 my $from    = $message->from;
 my $subject = $message->subject;
 my $msgid   = $message->messageId;

 my @to      = $message->to;
 my @cc      = $message->cc;
 my @bcc     = $message->bcc;
 my @dest    = $message->destinations;

 my $other   = $message->get('Reply-To');

consideration

Mail::Message::Field is the only object in the Mail::Box suite which is not derived from a Mail::Reporter. The consideration is that fields are so often created, and such a small objects at the same time, that setting-up a logging for each of the objects is relatively expensive and not really useful.

For the same reason, the are two types of fields: the flexible and the fast:

Mail::Message::Field::Flex

The flexible implementation uses a has to store the data. The new and init are split, so this object is extendible.

Mail::Message::Field::Fast

The fast implementation uses an array to store the same data. That will be faster. Furthermore, it is less extendible because the object creation and initiation is merged into one method.

As user of the object, there is not visible difference.

METHOD INDEX

The general methods for Mail::Message::Field objects:

      addresses                            name
      attribute NAME [, VALUE]             new ...
      body                                 print [FILEHANDLE]
      clone                                toDate TIME
      comment [STRING]                     toInt
      folded [ARRAY-OF-LINES]              toString

The extra methods for extension writers:

      isStructured                         nrLines
      newNoCheck NAME, BODY, COMM...       setWrapLength CHARS

METHODS

new LINE [,ARRAY-OF-OPTIONS]

new NAME, BODY [,COMMENT [, OPTIONS]]

new NAME, OBJECT|ARRAY-OF-OBJECTS [,COMMENT [, OPTIONS]]

Create a new header-object. Specify the whole header-LINE at once, and it will be split-up for you. I case you already have the parts of the header-line, you may specify them.

In structured fields (a list of pre-defined fields are considered to have a well-described format, checked with the isStructured method) everything behind a semi-color is officially a COMMENT. The comment is often (ab)used to supply extra information about the body information. When the field you specify is structured, and you do not specify a comment yourself, it will be stripped from the LINE or BODY for you.

To keep the communication overlead low (there are too many of these field-objects to be created), the OPTIONS may be specified as last argument to new, but as reference to an array. There are no options defined yet, but they may appear in the future.

In case you specify a single OBJECT, or a reference to an array of OBJECTS, these objects are processed to become suitable to fill a field. When you specify one or more Mail::Address objects, these are tranformed into a string using their format method.

You may also add one Mail::Message::Field, which body is taken. For other objects, stringification is tried. In case of an array, the elements are joined with a comma.

Examples:

   my @options = (log => 'NOTICE', trace => 'NONE');
   my $mime = Mail::Message::Field->new(
       'Content-Type: text/plain; charset=US-ASCII', \@options);

   my $mime = Mail::Message::Field->new(
       'Content-Type' => 'text/plain; charset=US-ASCII');

   my $mime = Mail::Message::Field->new(
       'Content-Type' => 'text/plain', 'charset=US-ASCII');

   my $mime = Mail::Message::Field->new(
       To => Mail::Address->new('my name', 'me@example.com');

   my $mime = Mail::Message::Field->new(
       Cc => [ Mail::Address->new('your name', 'you@example.com')
             , Mail::Address->new('his name', 'he@example.com')
             ]);

But, more often, you would call

   my $head = Mail::Message::Head->new;
   $head->add('Content-Type' => 'text/plain; charset=US-ASCII');

which implicitly calls this constructor (when needed). You can specify the same things for add as this new accepts.

clone

Create a copy of this field object.

name

Returns the name of this field, with all characters lower-cased for ease of comparison.

body

Returns the body of the field, unmodified but stripped from comment and CR LF characters (as far as were present at creation).

comment [STRING]

Returns the comment (part after a semi-colon) in the header-line, optionally after setting it to a new value first.

folded [ARRAY-OF-LINES]

Returns the folded version of the header. When the header is shorter than the wrap length, a list of one line is returned. Otherwise more lines will be returned, all but the first starting with a blank.

attribute NAME [, VALUE]

Get the value of an attribute, optionally after setting it to a new value. Attributes are part of some header lines, and hide themselves in the comment field. If the attribute does not exist, then undef is returned. For instance

 my $field = Mail::Message::Field->new(
    'Content-Type: text/plain; charset="us-ascii"');
 print $field->attribute('charset');        # --> us-ascii
 print $field->attribute('bitmap') || 'no'  # --> no

print [FILEHANDLE]

Print the whole header-line to the specified file-handle. One line may result in more than one printed line, because of the folding of long lines. The FILEHANDLE defaults to the selected handle.

toString

Returns the whole header-line.

Example:

    my @lines = $field->toString;
    print $field->toString;
    print "$field";

toInt

Returns the value which is related to this field as integer. A check is performed whether this is right.

toDate TIME

(Class method) Convert a timestamp into a MIME-acceptable date format.

Example:

 Mail::Message::Field->toDate(localtime);

addresses

Returns a list of Mail::Address objects, which represent the e-mail addresses found in this header line.

Example:

 my @addr = $message->head->get('to')->addresses;
 my @addr = $message->to;

METHODS for extension writers

isStructured

(object method or class method)

Examples:

   my $field = Mail::Message::Field->new(From => 'me');
   if($field->isStructured)

   Mail::Message::Field->isStructured('From');

nrLines

Returns the number of lines needed to display this header-line.

size

Returns the number of bytes needed to display this header-line.

setWrapLength CHARS

Make the header fold before the specified number of CHARS on a line. This will be ignored for un-structured headers.

newNoCheck NAME, BODY, COMMENT, [FOLDED]

(Class method) Do not use this yourself. This created an object without checking, which is ok when the parser is doing that already. However, if you add unchecked fields you may get into big trouble!

SEE ALSO

Mail::Box-Overview

AUTHOR

Mark Overmeer (mailbox@overmeer.net). All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

VERSION

This code is beta, version 2.009.

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