Venus::Role::Buildable

Buildable Role

Buildable Role for Perl 5

method: build_arg method: build_args method: build_data method: build_self method: build_nil

package Example;

use Venus::Class;

with 'Venus::Role::Buildable';

attr 'test';

package main;

my $example = Example->new;

# $example->test;

This package modifies the consuming package and provides methods for hooking into object construction of the consuming class, e.g. handling single-arg object construction.

The build_arg method, if defined, is only called during object construction when a single non-hashref is provided.

build_arg(any $data) (hashref)

{ since => '0.01', }

=example-1 build_arg

package Example1;

use Venus::Class;

attr 'x';
attr 'y';

with 'Venus::Role::Buildable';

sub build_arg {
  my ($self, $data) = @_;

  $data = { x => $data, y => $data };

  return $data;
}

package main;

my $example = Example1->new(10);

# $example->x;
# $example->y;

The build_args method, if defined, is only called during object construction to hook into the handling of the arguments provided.

build_args(hashref $data) (hashref)

{ since => '0.01', }

=example-1 build_args

package Example2;

use Venus::Class;

attr 'x';
attr 'y';

with 'Venus::Role::Buildable';

sub build_args {
  my ($self, $data) = @_;

  $data->{x} ||= int($data->{x} || 100);
  $data->{y} ||= int($data->{y} || 100);

  return $data;
}

package main;

my $example = Example2->new(x => 10, y => 10);

# $example->x;
# $example->y;

The build_data method, if defined, is only called during object construction to hook into the handling of the arguments provided. This method is passed two hashrefs, the first containing expected arguments provided to the constructor (e.g. attributes), and the second containing all unexpected arguments. The hashref or key/value pairs returned from this method will be used in subsequent automation.

build_data(hashref $args, hashref $xargs) (hashref)

{ since => '4.15', }

=example-1 build_data

package Example5;

use Venus::Class;

attr 'x';
attr 'y';

with 'Venus::Role::Buildable';

sub build_data {
  my ($self, $args, $xargs) = @_;

  $args->{z} = delete $xargs->{z} if !exists $args->{z} && exists $xargs->{z};

  return $args;
}

package main;

my $example = Example5->new(x => 10, y => 10, z => 10);

# $example->x;
# $example->y;

The build_self method, if defined, is only called during object construction after all arguments have been handled and set.

build_self(hashref $data) (object)

{ since => '0.01', }

=example-1 build_self

package Example3;

use Venus::Class;

attr 'x';
attr 'y';

with 'Venus::Role::Buildable';

sub build_self {
  my ($self, $data) = @_;

  die if !$self->x;
  die if !$self->y;

  return $self;
}

package main;

my $example = Example3->new(x => 10, y => 10);

# $example->x;
# $example->y;

The build_nil method, if defined, is only called during object construction when a single empty hashref is provided.

build_nil(hashref $data) (any)

{ since => '0.01', }

=example-1 build_nil

package Example4;

use Venus::Class;

attr 'x';
attr 'y';

with 'Venus::Role::Buildable';

sub build_nil {
  my ($self, $data) = @_;

  $data = { x => 10, y => 10 };

  return $data;
}

package main;

my $example = Example4->new({});

# $example->x;
# $example->y;

t/Venus.t: present: authors t/Venus.t: present: license

cpanm Venus

perl -MCPAN -e shell
install Venus