NAME

Data::Object::RoleHas

ABSTRACT

Data-Object Role Attribute Builder

SYNOPSIS

package Pointable;

use Data::Object::Role;
use Data::Object::RoleHas;

has 'x';
has 'y';

1;

DESCRIPTION

This package modifies the consuming package with behaviors useful in defining classes. Specifically, this package wraps the has attribute keyword functions and adds shortcuts and enhancements.

LIBRARIES

This package uses type constraints defined by:

Data::Object::Library

EXPORTS

This package automatically exports the following keywords.

has

package Person;

use Data::Object::Class;
use Data::Object::ClassHas;

has 'id';

has fname => (
  is => 'ro',
  isa => 'StrObj',
  crc => 1,
  req => 1
);

has lname => (
  is => 'ro',
  isa => 'StrObj',
  crc => 1,
  req => 1
);

1;

The has keyword is used to declare role attributes, which can be accessed and assigned to using the built-in getter/setter or by the object constructor. See Moo for more information.

is

is => 'ro' # read-only
is => 'rw' # read-write

The is directive is used to denote whether the attribute is read-only or read-write. See the Moo documentation for more details.

isa

# declare type constraint

isa => 'StrObject'
isa => 'ArrayObject'
isa => 'CodeObject'

The isa directive is used to define the type constraint to validate the attribute against. See the Moo documentation for more details.

req|required

# required attribute

req => 1
required => 1

The required directive is used to denote if an attribute is required or optional. See the Moo documentation for more details.

opt|optional

# optional attribute

opt => 1
optional => 1

The optional directive is used to denote if an attribute is optional or required. See the Moo documentation for more details.

bld|builder

# build value

bld => $builder
builder => $builder

The builder directive expects a coderef and builds the attribute value if it wasn't provided to the constructor. See the Moo documentation for more details.

clr|clearer

# create clear_${attribute}

clr => $clearer
clearer => $clearer

The clearer directive expects a coderef and generates a clearer method. See the Moo documentation for more details.

crc|coerce

# coerce value

crc => 1
coerce => 1

The coerce directive denotes whether an attribute's value should be automatically coerced. See the Moo documentation for more details.

def|default

# default value

def => $default
default => $default

The default directive expects a coderef and is used to build a default value if one is not provided to the constructor. See the Moo documentation for more details.

mod|modify

# modify definition

mod => 1
modify => 1

The modify directive denotes whether a pre-existing attribute's definition is being modified. This ability is not supported by the Moo object superclass.

hnd|handles

# dispatch to value

hnd => $handles
handles => $handles

The handles directive denotes the methods created on the object which dispatch to methods available on the attribute's object. See the Moo documentation for more details.

lzy|lazy

# lazy attribute

lzy => 1
lazy => 1

The lazy directive denotes whether the attribute will be constructed on-demand, or on-construction. See the Moo documentation for more details.

new

# lazy attribute
# create new_${attribute}

new => 1

The new directive, if truthy, denotes that the attribute will be constructed on-demand, i.e. is lazy, with a builder named new_{attribute}. This ability is not supported by the Moo object superclass.

pre|predicate

# create has_${attribute}

pre => 1
predicate => 1

The predicate directive expects a coderef and generates a method for checking the existance of the attribute. See the Moo documentation for more details.

rdr|reader

# attribute reader

rdr => $reader
reader => $reader

The reader directive denotes the name of the method to be used to "read" and return the attribute's value. See the Moo documentation for more details.

tgr|trigger

# attribute trigger

tgr => $trigger
trigger => $trigger

The trigger directive expects a coderef and is executed whenever the attribute's value is changed. See the Moo documentation for more details.

use

# lazy dependency injection

use => ['service', 'datetime']

The use directive denotes that the attribute will be constructed on-demand, i.e. is lazy, using a custom builder meant to perform service construction. This directive exists to provide a simple dependency injection mechanism for class attributes. This ability is not supported by the Moo object superclass.

wkr|weak_ref

# weaken ref

wkr => 1
weak_ref => 1

The weak_ref directive is used to denote if the attribute's value should be weakened. See the Moo documentation for more details.

wrt|writer

# attribute writer

wrt => $writer
writer => $writer

The writer directive denotes the name of the method to be used to "write" and return the attribute's value. See the Moo documentation for more details.

CREDITS

Al Newkirk, +319

Anthony Brummett, +10

Adam Hopkins, +2

José Joaquín Atria, +1

AUTHOR

Al Newkirk, awncorp@cpan.org

LICENSE

This is free software; you can redistribute it and/or modify it under the terms of the The Apache License, Version 2.0, as elucidated here, https://github.com/iamalnewkirk/do/blob/master/LICENSE.