Term::...ashBase(3perl) Perl Programmers Reference GuideTerm::...ashBase(3perl)
NAME
Term::Table::HashBase - Build hash based classes.
SYNOPSIS
A class:
package My::Class;
use strict;
use warnings;
# Generate 3 accessors
use Term::Table::HashBase qw/foo -bar ^baz <bat >ban +boo/;
# Chance to initialize defaults
sub init {
my $self = shift; # No other args
$self->{+FOO} ||= "foo";
$self->{+BAR} ||= "bar";
$self->{+BAZ} ||= "baz";
$self->{+BAT} ||= "bat";
$self->{+BAN} ||= "ban";
$self->{+BOO} ||= "boo";
}
sub print {
print join ", " => map { $self->{$_} } FOO, BAR, BAZ, BAT, BAN, BOO;
}
Subclass it
package My::Subclass;
use strict;
use warnings;
# Note, you should subclass before loading HashBase.
use base 'My::Class';
use Term::Table::HashBase qw/bub/;
sub init {
my $self = shift;
# We get the constants from the base class for free.
$self->{+FOO} ||= 'SubFoo';
$self->{+BUB} ||= 'bub';
$self->SUPER::init();
}
use it:
package main;
use strict;
use warnings;
use My::Class;
# These are all functionally identical
my $one = My::Class->new(foo => 'MyFoo', bar => 'MyBar');
my $two = My::Class->new({foo => 'MyFoo', bar => 'MyBar'});
my $three = My::Class->new(['MyFoo', 'MyBar']);
# Readers!
my $foo = $one->foo; # 'MyFoo'
my $bar = $one->bar; # 'MyBar'
my $baz = $one->baz; # Defaulted to: 'baz'
my $bat = $one->bat; # Defaulted to: 'bat'
# '>ban' means setter only, no reader
# '+boo' means no setter or reader, just the BOO constant
# Setters!
$one->set_foo('A Foo');
#'-bar' means read-only, so the setter will throw an exception (but is defined).
$one->set_bar('A bar');
# '^baz' means deprecated setter, this will warn about the setter being
# deprecated.
$one->set_baz('A Baz');
# '<bat' means no setter defined at all
# '+boo' means no setter or reader, just the BOO constant
$one->{+FOO} = 'xxx';
DESCRIPTION
This package is used to generate classes based on hashrefs. Using this
class will give you a new() method, as well as generating accessors you
request. Generated accessors will be getters, "set_ACCESSOR" setters
will also be generated for you. You also get constants for each accessor
(all caps) which return the key into the hash for that accessor. Single
inheritance is also supported.
THIS IS A BUNDLED COPY OF HASHBASE
This is a bundled copy of Object::HashBase. This file was generated
using the "/home/exodist/perl5/perlbrew/perls/main/bin/hashbase_inc.pl"
script.
METHODS
PROVIDED BY HASH BASE
$it = $class->new(%PAIRS)
$it = $class->new(\%PAIRS)
$it = $class->new(\@ORDERED_VALUES)
Create a new instance.
HashBase will not export new() if there is already a new() method in
your packages inheritance chain.
If you do not want this method you can define your own you just have
to declare it before loading Term::Table::HashBase.
package My::Package;
# predeclare new() so that HashBase does not give us one.
sub new;
use Term::Table::HashBase qw/foo bar baz/;
# Now we define our own new method.
sub new { ... }
This makes it so that HashBase sees that you have your own new()
method. Alternatively you can define the method before loading
HashBase instead of just declaring it, but that scatters your use
statements.
The most common way to create an object is to pass in key/value
pairs where each key is an attribute and each value is what you want
assigned to that attribute. No checking is done to verify the
attributes or values are valid, you may do that in init() if
desired.
If you would like, you can pass in a hashref instead of pairs. When
you do so the hashref will be copied, and the copy will be returned
blessed as an object. There is no way to ask HashBase to bless a
specific hashref.
In some cases an object may only have 1 or 2 attributes, in which
case a hashref may be too verbose for your liking. In these cases
you can pass in an arrayref with only values. The values will be
assigned to attributes in the order the attributes were listed. When
there is inheritance involved the attributes from parent classes
will come before subclasses.
HOOKS
$self->init()
This gives you the chance to set some default values to your fields.
The only argument is $self with its indexes already set from the
constructor.
Note: Term::Table::HashBase checks for an init using
"$class->can('init')" during construction. It DOES NOT call can() on
the created object. Also note that the result of the check is
cached, it is only ever checked once, the first time an instance of
your class is created. This means that adding an init() method AFTER
the first construction will result in it being ignored.
ACCESSORS
READ/WRITE
To generate accessors you list them when using the module:
use Term::Table::HashBase qw/foo/;
This will generate the following subs in your namespace:
foo()
Getter, used to get the value of the "foo" field.
set_foo()
Setter, used to set the value of the "foo" field.
FOO()
Constant, returns the field "foo"'s key into the class hashref.
Subclasses will also get this function as a constant, not simply a
method, that means it is copied into the subclass namespace.
The main reason for using these constants is to help avoid spelling
mistakes and similar typos. It will not help you if you forget to
prefix the '+' though.
READ ONLY
use Term::Table::HashBase qw/-foo/;
set_foo()
Throws an exception telling you the attribute is read-only. This is
exported to override any active setters for the attribute in a
parent class.
DEPRECATED SETTER
use Term::Table::HashBase qw/^foo/;
set_foo()
This will set the value, but it will also warn you that the method
is deprecated.
NO SETTER
use Term::Table::HashBase qw/<foo/;
Only gives you a reader, no "set_foo" method is defined at all.
NO READER
use Term::Table::HashBase qw/>foo/;
Only gives you a write ("set_foo"), no "foo" method is defined at all.
CONSTANT ONLY
use Term::Table::HashBase qw/+foo/;
This does not create any methods for you, it just adds the "FOO"
constant.
SUBCLASSING
You can subclass an existing HashBase class.
use base 'Another::HashBase::Class';
use Term::Table::HashBase qw/foo bar baz/;
The base class is added to @ISA for you, and all constants from base
classes are added to subclasses automatically.
GETTING A LIST OF ATTRIBUTES FOR A CLASS
Term::Table::HashBase provides a function for retrieving a list of
attributes for an Term::Table::HashBase class.
@list = Term::Table::HashBase::attr_list($class)
@list = $class->Term::Table::HashBase::attr_list()
Either form above will work. This will return a list of attributes
defined on the object. This list is returned in the attribute
definition order, parent class attributes are listed before subclass
attributes. Duplicate attributes will be removed before the list is
returned.
Note: This list is used in the "$class->new(\@ARRAY)" constructor to
determine the attribute to which each value will be paired.
SOURCE
The source code repository for HashBase can be found at
http://github.com/Test-More/HashBase/.
MAINTAINERS
Chad Granum <exodist@cpan.org>
AUTHORS
Chad Granum <exodist@cpan.org>
COPYRIGHT
Copyright 2017 Chad Granum <exodist@cpan.org>.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See http://dev.perl.org/licenses/
perl v5.40.1 2026-08-30 Term::...ashBase(3perl)
Generated by dwww version 1.16 on Sat Oct 3 06:47:48 CEST 2026.