Class::Accessor::Classy

NAME

Class::Accessor::Classy - accessors with minimal inheritance

SYNOPSIS

  package YourPackage;
  use Class::Accessor::Classy;
    with qw(new);              # with a new() method
    ro qw(foo);                # read-only
    rw qw(bar);                # read-write
    rs baz => \ (my $set_baz); # read-only, plus a secret writer
    # alternatively:
    my $set_bip = rs 'bip';
    ro_c suitcase => 'red';    # read-only class data
    rw_c hat      => 'black';  # read-write class data
    rs_c socks    => \ (my $set_socks) => undef;
    # alternative secret writer syntax
    my $set_shoes = rs_c shoes => undef;
    # also class read-only:
    constant seven => 7;
    constant eight => this->seven + 1;
  no  Class::Accessor::Classy;
  # ^-- removes all of the syntax bits from your namespace
  package whatever;
  YourPackage->set_hat(undef);
  my $obj = YourPackage->new(foo => 4, bar => 2);
  # NOTE I'm thinking of deprecating the get_foo() usage
  warn "foo ", $obj->foo;
  YourPackage->$set_socks("tube");

This module provides an extremely small-footprint accessor/mutator declaration scheme for fast and convenient object attribute setup. It is intended as a simple and speedy mechanism for preventing hash-key typos rather than a full-blown object system with type checking and so on.

The accessor methods appear as a hidden parent class of your package and generally try to stay out of the way. The accessors and mutators generated are of the form "foo()" and "set_foo()", respectively.

Frontend

Unlike other class-modifying code, this is not designed to be inherited from. Instead, you simply use it and get an invisible subclass containing your accessors. If you use the 'no' syntax (to call unimport), you are left with a squeaky-clean namespace.

After 'use' and before 'no', the following pieces of syntax are available.

with

Add a 'standard' method to your class.

new

ro

Read-only properties (accessors only.)

  ro qw(foo bar baz);

rw

Define read-write (accessor + mutator) properties.

  rw qw(foo bar baz);

lv

Properties with lvalue accessors.

  lv qw(thing deal stuff);

ri

Immutable properties. Once set, further calls to the mutator throw errors.

  ri qw(foo bar baz);

rs

Read-only properties with a secret mutator.

  rs foo => \(my $set_foo);

lo

Read-only list properties. These are stored as an array-ref, but the accessor returns a list.

  lo qw(foo bar baz);

lw

Read-write list properties. The mutator takes a list.

  lw 'foo';

This defaults to create foo()|get_foo(), set_foo(), and add_foo() methods. Other features are possible here, but currently experimental.

ls

List property with a secret mutator.

  ls foo => \(my $set_foo);

this

A shortcut for your classname. Useful for e.g. defining one constant in terms of another.

  this->some_class_method;

getter

Define a custom getter.

setter

Define a custom setter.

constant

A class constant.

  constant foo => 7;

ro_c

Read-only class method.

rw_c

A read-write class method, with a default.

  rw_c foo => 9;

rs_c

A class method with a secret setter.

  rs_c bar => \(my $set_bar) => 12;

in

Specify the destination package. You need to set this before defining anything else (but it is usually best to just not set it.)

  in 'why_be_so_secretive';

aka

Add an alias for an existing method.

  aka have_method => 'want_method', 'and_also_want';

Utilities

This introspection stuff is unreliable -- don't use it.

find_accessors

  @attribs = Class::Accessor::Classy->find_accessors($class);

find_subclasses

  @classlist = Class::Accessor::Classy->find_subclasses($class);

Subclassable

Customized subclasses may override these methods to create a new kind of accessor generator.

NOTE: You do not subclass Class::Accessor::Classy to construct your objects. If you are just creating MyObject, you are not inheriting any of these methods. The rest of this documentation only pertains to you if you are trying to create something like Class::Accessor::Classy::MyWay.

notation:: Read these as: $CAC = 'Class::Accessor::Classy'; (or whatever subclass you're creating.)

exports

  my %exports = $CAC->exports;

import

  $CAC->import;

unimport

  $CAC->unimport;

create_package

Creates and returns the package in which the accessors will live. Also pushes the created accessor package into the caller's @ISA.

If it already exists, simply returns the cached value.

  my $package = $CAC->create_package(
    class => $caller,
    in    => $package, # optional
  );

install_sub

  $CAC->install_sub($class, $name, $subref, $note);

annotate

  $CAC->annotate($class, $name, $note);

get_notes

  my %notes = $CAC->get_notes;

make_standards

  $CAC->make_standards($class, @list);

_getter

Returns a compiled getter subref corresponding to whether or not the class has a '--get' method.

  $CAC->_getter($class, $item);

make_getters

  $CAC->make_getters($class, @list);

make_lv_getters

  $CAC->make_lv_getters($class, @list);

_setter

Returns a compiled setter subref corresponding to whether or not the class has a '--set' method.

  $CAC->_setter($class, $item);

make_setters

  $CAC->make_setters($class, @list);

make_immutable

Creates immutable (one-time-only) setters.

  CAC->make_immutable($class, @list);

make_secrets

  my @names = $CAC->make_secrets($class, @list);

make_aliases

Constructs 'get_' aliases for a @list of accessors.

  $CAC->make_aliases($class, @list);

make_aka

Create a list of alias methods which runtime refer to $realname.

  $CAC->make_aka($where, $realname, @aliases);

do_eval

  my $subref = $package->do_eval($string, @checks);

List Accessors

make_array_method

  $CAC->make_array_method(
    class     => $class,
    item      => $name,
    functions => [@functions],
    secret    => $bool,
  );

If secret is true, will return the list of names.

_get_array_subs

  my %subs = $CAC->_get_array_subs($name);

Class Accessors

make_class_data

  $CAC->make_class_data($mode, $class, $key, $value);

If mode is 'rs', returns the secret setter name.

perl v5.36.0

Recommended readings

Questions & Answers