/ 
Mail-Box-2.017
River stage one • 8 direct dependents • 8 total dependents
/ Mail::Message::Field

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;
print $field->content;  # body & 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                            new ...
attribute NAME [, VALUE]             print [FILEHANDLE]
body                                 toDate TIME
comment [STRING]                     toInt
content                              toString
folded [ARRAY-OF-LINES]              wellformedName ...
name

The extra methods for extension writers:

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

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.

name

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

wellformedName
wellformedName [STRING]

(Instance method class method) As instance method, the current field's name is correctly formatted and returned. When a STRING is used, that one is formatted.

Examples:

print Mail::Message::Field->Name('content-type') # Content-Type

my $field = $head->get('date');
print $field->Name;                              # Date
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.

content

Returns the body and comment part of the field, separated by a semi-colon.

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 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

clone

Create a copy of this field object.

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

For support and additional documentation, see http://perl.overmeer.net/mailbox/

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 2.017.

Copyright (c) 2001-2002 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.