Mail::Field(3) User Contributed Perl Documentation Mail::Field(3)NAMEMail::Field - Base class for manipulation of mail header fields
SYNOPSIS
use Mail::Field;
$field = Mail::Field->new('Subject', 'some subject text');
print $field->tag,": ",$field->stringify,"\n";
$field = Mail::Field->subject('some subject text');
DESCRIPTION
"Mail::Field" is a base class for packages that create and manipulate
fields from Email (and MIME) headers. Each different field will have
its own sub-class, defining its own interface.
This document describes the minimum interface that each sub-class
should provide, and also guidlines on how the field specific interface
should be defined.
CONSTRUCTOR
Mail::Field, and it's sub-classes define several methods which return
new objects. These can all be termed to be constructors.
new ( TAG [, STRING | OPTIONS ] )
The new constructor will create an object in the class which
defines the field specified by the tag argument.
After creation of the object :-
If the tag argument is followed by a single string then the "parse"
method will be called with this string.
If the tag argument is followed by more than one arguments then the
"create" method will be called with these arguments.
extract ( TAG, HEAD [, INDEX ] )
This constuctor takes as arguments the tag name, a "Mail::Head"
object and optionally an index.
If the index argument is given then "extract" will retrieve the
given tag from the "Mail::Head" object and create a new
"Mail::Field" based object. undef will be returned in the field
does not exist.
If the index argument is not given the the result depends on the
context in which "extract" is called. If called in a scalar context
the result will be as if "extract" was called with an index value
of zero. If called in an array context then all tags will be
retrieved and a list of "Mail::Field" objects will be returned.
combine ( FIELD_LIST )
This constructor takes as arguments a list of "Mail::Field"
objects, which should all be of the same sub-class, and creates a
new object in that same class.
This constructor is nor defined in "Mail::Field" as there is no
generic way to combine the various field types. Each sub-class
should define its own combine constructor, if combining is possi-
ble/allowed.
METHODS
parse
set
tag
stringify
SUB-CLASS PACKAGE NAMES
All sub-classes should be called Mail::Field::name where name is
derived from the tag using these rules.
o Consider a tag as being made up of elements separated by '-'
o Convert all characters to lowercase except the first in each ele-
ment, which should be uppercase.
o name is then created from these elements by using the first N char-
acters from each element.
o N is calculated by using the formula :-
int((7 + #elements) / #elements)
o name is then limited to a maximum of 8 characters, keeping the
first 8 characters
For an example of this take a look at the definition of the
"_header_pkg_name" subroutine in "Mail::Field"
AUTHOR
Graham Barr.
Maintained by Mark Overmeer <mailtools@overmeer.net>
SEE ALSO
MIME::*s
CREDITS
Eryq <eryq@rhine.gsfc.nasa.gov> - for all the help in defining this
package so that "Mail::*" and "MIME::*" can be integrated together.
COPYRIGHT
Copyright (c) 2002-2003 Mark Overmeer, 1995-2001 Graham Barr. All
rights reserved. This program is free software; you can redistribute it
and/or modify it under the same terms as Perl itself.
perl v5.8.8 2007-05-11 Mail::Field(3)