NAME¶
Mail::Field - Base class for manipulation of mail header fields
INHERITANCE¶
Mail::Field is extended by
Mail::Field::AddrList
Mail::Field::Date
Mail::Field::Generic
SYNOPSIS¶
use Mail::Field;
my $field = Mail::Field->new('Subject', 'some subject text');
my $field = Mail::Field->new(Subject => 'some subject text');
print $field->tag,": ",$field->stringify,"\n";
my $field = Mail::Field->subject('some subject text');
DESCRIPTION¶
"Mail::Field" creates and manipulates fields in MIME headers,
collected within a Mail::Header object. Different field types have their own
sub-class (extension), defining additional useful accessors to the field
content.
People are invited to merge their implementation to special fields into
MailTools, to maintain a consistent set of packages and documentation.
METHODS¶
Constructors¶
Mail::Field (and it's sub-classes) define several methods which return new
objects. These can all be categorized as constructor.
- Mail::Field->combine(FIELDS)
- Take a LIST of "Mail::Field" objects (which should all be of the
same sub-class) and create a new object in that same class.
- Mail::Field->extract(TAG, HEAD [, INDEX ])
- 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 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.
- Mail::Field->new(TAG [, STRING | OPTIONS])
- Create an object in the class which defines the field specified by the TAG
argument.
"Fake" constructors¶
- $obj->create(OPTIONS)
- This constructor is used internally with preprocessed field information.
When called on an existing object, its original content will get
replaced.
- $obj->parse()
- Parse a field line.
Accessors¶
- $obj->set(OPTIONS)
- Change the settings (the content, but then smart) of this field.
- $obj->stringify()
- Returns the field as a string.
- $obj->tag()
- Mail::Field->tag()
- Return the tag (in the correct case) for this item. Well, actually any
casing is OK, because the field tags are treated case-insensitive; however
people have some preferences.
Smart accessors¶
- $obj->text([STRING])
- Without arguments, the field is returned as stringify() does.
Otherwise, the STRING is parsed with parse() to replace the
object's content.
It is more clear to call either stringify() or parse()
directly, because this method does not add additional processing.
DETAILS¶
SUB-CLASS PACKAGE NAMES¶
All sub-classes should be called Mail::Field::
name where
name is
derived from the tag using these rules.
- •
- Consider a tag as being made up of elements separated by '-'
- •
- Convert all characters to lowercase except the first in each element,
which should be uppercase.
- •
- name is then created from these elements by using the first N
characters from each element.
- •
- N is calculated by using the formula :-
int((7 + #elements) / #elements)
- •
- 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"
DIAGNOSTICS¶
- Error: Undefined subroutine <method> called
- Mail::Field objects use autoloading to compile new functionality.
Apparently, the method called is not implemented for the specific class of
the field object.
SEE ALSO¶
This module is part of the MailTools distribution,
http://perl.overmeer.net/mailtools/.
AUTHORS¶
The MailTools bundle was developed by Graham Barr. Later, Mark Overmeer took
over maintenance without commitment to further development.
Mail::Cap by Gisle Aas <aas@oslonett.no>. Mail::Field::AddrList by Peter
Orbaek <poe@cit.dk>. Mail::Mailer and Mail::Send by Tim Bunce
<Tim.Bunce@ig.co.uk>. For other contributors see ChangeLog.
LICENSE¶
Copyrights 1995-2000 Graham Barr <gbarr@pobox.com> and 2001-2007 Mark
Overmeer <perl@overmeer.net>.
This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself. See
http://www.perl.com/perl/misc/Artistic.html