Venus::Role::Makeable

Makeable Role

Makeable Role for Perl 5

method: make_args method: make_attr method: make_into method: make_onto method: makers method: making

package Person;

use Venus::Class 'attr', 'error', 'with';

with 'Venus::Role::Makeable';

attr 'name';
attr 'father';
attr 'mother';
attr 'siblings';

sub make {
  my ($self, $value) = @_;

  error if !ref $value;

  return $self->new($value);
}

sub makers {
  {
    father => 'Person',
    mother => 'Person',
    name => 'Venus/String',
    siblings => 'Person',
  }
}

sub make_name {
  my ($self, $code, @args) = @_;

  return $self->$code(@args);
}

sub make_siblings {
  my ($self, $code, $class, $value) = @_;

  return [map $self->$code($class, $_), @$value];
}

package main;

my $person = Person->make({
  name => 'me',
  father => {name => 'father'},
  mother => {name => 'mother'},
  siblings => [{name => 'brother'}, {name => 'sister'}],
});

# $person
# bless({...}, 'Person')

# $person->name
# bless({...}, 'Venus::String')

# $person->father
# bless({...}, 'Person')

# $person->mother
# bless({...}, 'Person')

# $person->siblings
# [bless({...}, 'Person'), bless({...}, 'Person'), ...]

This package modifies the consuming package and provides methods for hooking into object construction and coercing arguments into objects and values using the "make" protocol, i.e. using the "make" method (which performs fatal type checking and coercions) instead of the typical "new" method.

The make_args method replaces values in the data provided with objects corresponding to the specification provided. The specification should contains key/value pairs where the keys map to class attributes (or input parameters) and the values are Venus::Space compatible package names.

make_args(hashref $data, hashref $spec) (hashref)

{ since => '1.30', }

=example-1 make_args

package main;

my $person = Person->new;

my $data = $person->make_args(
  {
    father => { name => 'father' }
  },
  {
    father => 'Person',
  },
);

# {
#   father   => bless({...}, 'Person'),
# }

The make_attr method is a surrogate accessor and gets and/or sets an instance attribute based on the makers rules, returning the made value.

make_attr(string $name, any $value) (any)

{ since => '1.30', }

=example-1 make_attr

# given: synopsis

package main;

$person = Person->new(
  name => 'me',
);

my $make_name = $person->make_attr('name');

# bless({value => "me"}, "Venus::String")

The make_into method attempts to build and return an object based on the class name and value provided, unless the value provided is already an object derived from the specified class.

make_into(string $class, any $value) (object)

{ since => '1.30', }

=example-1 make_into

package main;

my $person = Person->new;

my $friend = $person->make_into('Person', {
  name => 'friend',
});

# bless({...}, 'Person')

The make_onto method attempts to build and assign an object based on the class name and value provided, as the value corresponding to the name specified, in the data provided. If the $value is omitted, the value corresponding to the name in the $data will be used.

make_onto(hashref $data, string $name, string $class, any $value) (object)

{ since => '1.30', }

=example-1 make_onto

package main;

my $person = Person->new;

my $data = { friend => { name => 'friend' } };

my $friend = $person->make_onto($data, 'friend', 'Person');

# bless({...}, 'Person'),

# $data was updated
#
# {
#   friend => bless({...}, 'Person'),
# }

The makers method, if defined, is called during object construction, or by the "making" method, and returns key/value pairs where the keys map to class attributes (or input parameters) and the values are Venus::Space compatible package names.

makers() (hashref)

{ since => '1.30', }

=example-1 makers

package main;

my $person = Person->new(
  name => 'me',
);

my $makers = $person->makers;

# {
#   father   => "Person",
#   mother   => "Person",
#   name     => "Venus/String",
#   siblings => "Person",
# }

The making method is called automatically during object construction but can be called manually as well, and is passed a hashref to make and return.

making(hashref $data) (hashref)

{ since => '1.30', }

=example-1 making

package main;

my $person = Person->new;

my $making = $person->making({
  name => 'me',
});

# $making
# {...}

# $making->{name}
# bless({...}, 'Venus::String')

# $making->{father}
# undef

# $making->{mother}
# undef

# $making->{siblings}
# undef

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

cpanm Venus

perl -MCPAN -e shell
install Venus