NAME

    Data::Object::Attributes

ABSTRACT

    Attribute Builder for Perl 5

SYNOPSIS

      package Example;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has 'data';
    
      package main;
    
      my $example = Example->new;

DESCRIPTION

    This package provides options for defining class attributes.
    Specifically, this package wraps the has attribute keyword and adds
    shortcuts and enhancements. If no directives are specified, the
    attribute is declared as read-write and optional.

SCENARIOS

    This package supports the following scenarios:

 has-bld

      package Example::HasBld;
    
      use Moo;
      use routines;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        bld => 1
      );
    
      method _build_data() {
    
        return time;
      }
    
      package main;
    
      my $example = Example::HasBld->new;

    This package supports the bld and builder directives, expects a 1, a
    method name, or coderef and builds the attribute value if it wasn't
    provided to the constructor. See the Moo documentation for more
    details.

 has-clr

      package Example::HasClr;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        clr => 1
      );
    
      package main;
    
      my $example = Example::HasClr->new(data => time);
    
      # $example->clear_data;

    This package supports the clr and clearer directives expects a 1 or a
    method name of the clearer method. See the Moo documentation for more
    details.

 has-crc

      package Example::HasCrc;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        crc => fun($arg){'0'}
      );
    
      package main;
    
      my $example = Example::HasCrc->new(data => time);

    This package supports the crc and coerce directives denotes whether an
    attribute's value should be automatically coerced. See the Moo
    documentation for more details.

 has-def

      package Example::HasDef;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        def => '0'
      );
    
      package main;
    
      my $example = Example::HasDef->new;

    This package supports the def and default directives expects a
    non-reference or a coderef to be used to build a default value if one
    is not provided to the constructor. See the Moo documentation for more
    details.

 has-hnd

      package Example::Time;
    
      use Moo;
      use routines;
    
      method maketime() {
    
        return time;
      }
    
      package Example::HasHnd;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        hnd => ['maketime']
      );
    
      package main;
    
      my $example = Example::HasHnd->new(data => Example::Time->new);

    This package supports the hnd and handles directives denotes the
    methods created on the object which dispatch to methods available on
    the attribute's object. See the Moo documentation for more details.

 has-is

      package Example::HasIs;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro'
      );
    
      package main;
    
      my $example = Example::HasIs->new(data => time);

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

 has-isa

      package Example::HasIsa;
    
      use Moo;
      use registry;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        isa => 'Str' # e.g. Types::Standard::Str
      );
    
      package main;
    
      my $example = Example::HasIsa->new(data => time);

    This package supports the isa directive, used to define the type
    constraint to validate the attribute against. See the Moo documentation
    for more details.

 has-lzy

      package Example::HasLzy;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        def => fun(){time},
        lzy => 1
      );
    
      package main;
    
      my $example = Example::HasLzy->new;

    This package supports the lzy and lazy directives denotes whether the
    attribute will be constructed on-demand, or on-construction. See the
    Moo documentation for more details.

 has-mod

      package Example::Has;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'rw',
        opt => 1
      );
    
      package Example::HasMod;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      extends 'Example::Has';
    
      has data => (
        is => 'ro',
        req => 1,
        mod => 1
      );
    
      package main;
    
      my $example = Example::HasMod->new;

    This package supports the mod and modify directives denotes whether a
    pre-existing attribute's definition is being modified. This ability is
    not supported by the Moo object superclass.

 has-new

      package Example::HasNew;
    
      use Moo;
      use routines;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        new => 1
      );
    
      fun new_data($self) {
    
        return time;
      }
    
      package main;
    
      my $example = Example::HasNew->new(data => time);

    This package supports 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.

 has-opt

      package Example::HasOpt;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        opt => 1
      );
    
      package main;
    
      my $example = Example::HasOpt->new(data => time);

    This package supports the opt and optional directives, used to denote
    if an attribute is optional or required. See the Moo documentation for
    more details.

 has-pre

      package Example::HasPre;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        pre => 1
      );
    
      package main;
    
      my $example = Example::HasPre->new(data => time);

    This package supports the pre and predicate directives expects a 1 or a
    method name and generates a method for checking the existance of the
    attribute. See the Moo documentation for more details.

 has-rdr

      package Example::HasRdr;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        rdr => 'get_data'
      );
    
      package main;
    
      my $example = Example::HasRdr->new(data => time);

    This package supports the rdr and reader directives denotes the name of
    the method to be used to "read" and return the attribute's value. See
    the Moo documentation for more details.

 has-req

      package Example::HasReq;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        req => 1 # required
      );
    
      package main;
    
      my $example = Example::HasReq->new(data => time);

    This package supports the req and required directives, used to denote
    if an attribute is required or optional. See the Moo documentation for
    more details.

 has-tgr

      package Example::HasTgr;
    
      use Moo;
      use routines;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        tgr => 1
      );
    
      method _trigger_data() {
        $self->{triggered} = 1;
    
        return $self;
      }
    
      package main;
    
      my $example = Example::HasTgr->new(data => time);

    This package supports the tgr and trigger directives expects a 1 or a
    coderef and is executed whenever the attribute's value is changed. See
    the Moo documentation for more details.

 has-use

      package Example::HasUse;
    
      use Moo;
      use routines;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        use => ['service', 'time']
      );
    
      method service($type, @args) {
        $self->{serviced} = 1;
    
        return time if $type eq 'time';
      }
    
      package main;
    
      my $example = Example::HasUse->new;

    This package supports 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.

 has-wkr

      package Example::HasWkr;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        wkr => 1
      );
    
      package main;
    
      my $data = do {
        my ($a, $b);
    
        $a = { time => time };
        $b = { time => $a };
    
        $a->{time} = $b;
        $a
      };
    
      my $example = Example::HasWkr->new(data => $data);

    This package supports the wkr and weak_ref directives is used to denote
    if the attribute's value should be weakened. See the Moo documentation
    for more details.

 has-wrt

      package Example::HasWrt;
    
      use Moo;
    
      use Data::Object::Attributes;
    
      has data => (
        is => 'ro',
        wrt => 'set_data'
      );
    
      package main;
    
      my $example = Example::HasWrt->new;

    This package supports the wrt and writer directives denotes the name of
    the method to be used to "write" and return the attribute's value. See
    the Moo documentation for more details.

AUTHOR

    Al Newkirk, awncorp@cpan.org

LICENSE

    Copyright (C) 2011-2019, Al Newkirk, et al.

    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 in the
    "license file"
    <https://github.com/iamalnewkirk/data-object-attributes/blob/master/LICENSE>.

PROJECT

    Wiki <https://github.com/iamalnewkirk/data-object-attributes/wiki>

    Project <https://github.com/iamalnewkirk/data-object-attributes>

    Initiatives
    <https://github.com/iamalnewkirk/data-object-attributes/projects>

    Milestones
    <https://github.com/iamalnewkirk/data-object-attributes/milestones>

    Contributing
    <https://github.com/iamalnewkirk/data-object-attributes/blob/master/CONTRIBUTE.md>

    Issues <https://github.com/iamalnewkirk/data-object-attributes/issues>