NAME

Venus::Role::Subscribable - Subscribable Role

ABSTRACT

Subscribable Role for Perl 5

SYNOPSIS

  package Example;

  use Venus::Class;

  with 'Venus::Role::Subscribable';

  sub execute {
    $_[0]->publish('on.execute');
  }

  package main;

  my $example = Example->new;

  # $example->subscribe('on.execute', sub{...});

  # bless(..., 'Example')

  # $example->publish('on.execute');

  # bless(..., 'Example')

DESCRIPTION

This package provides a mechanism for publishing and subscribing to events.

METHODS

This package provides the following methods:

publish

  publish(Str $name, Any @args) (Self)

The publish method notifies all subscribers for a given event and returns the invocant.

Since 1.75

publish example 1

  # given: synopsis

  package main;

  $example = $example->publish;

  # bless(..., 'Example')

publish example 2

  # given: synopsis

  package main;

  $example = $example->publish('on.execute');

  # bless(..., 'Example')

publish example 3

  # given: synopsis

  package main;

  $example->subscribe('on.execute', sub {$example->{emitted} = [@_]});

  $example = $example->publish('on.execute');

  # bless(..., 'Example')

publish example 4

  # given: synopsis

  package main;

  $example->subscribe('on.execute', sub {$example->{emitted} = [@_]});

  $example = $example->publish('on.execute', [1..4]);

  # bless(..., 'Example')

subscribe

  subscribe(Str $name, CodeRef $code) (Self)

The subscribe method registers a subscribers (i.e. callbacks) for a given event, and returns the invocant.

Since 1.75

subscribe example 1

  # given: synopsis

  package main;

  $example = $example->subscribe('on.execute', sub {$example->{emitted} = [@_]});

  # bless(..., 'Example')

subscribe example 2

  # given: synopsis

  package main;

  $example = $example->subscribe('on.execute', sub {$example->{emitted_1} = [@_]});

  # bless(..., 'Example')

  $example = $example->subscribe('on.execute', sub {$example->{emitted_2} = [@_]});

  # bless(..., 'Example')

  $example = $example->subscribe('on.execute', sub {$example->{emitted_3} = [@_]});

  # bless(..., 'Example')

  # $example->publish('on.execute');

  # bless(..., 'Example')

subscribers

  subscribers(Str $name) (Int)

The subscribers method returns the number of subscribers (i.e. callbacks) for a given event.

Since 1.75

subscribers example 1

  # given: synopsis

  package main;

  $example = $example->subscribers;

  # 0

subscribers example 2

  # given: synopsis

  package main;

  $example = $example->subscribers('on.execute');

  # 0

subscribers example 3

  # given: synopsis

  package main;

  $example = $example->subscribe('on.execute', sub {$example->{emitted_1} = [@_]});

  $example = $example->subscribe('on.execute', sub {$example->{emitted_2} = [@_]});

  $example = $example->subscribe('on.execute', sub {$example->{emitted_3} = [@_]});

  $example = $example->subscribers('on.execute');

  # 3

unsubscribe

  unsubscribe(Str $name, CodeRef $code) (Self)

The unsubscribe method deregisters all subscribers (i.e. callbacks) for a given event, or a specific callback if provided, and returns the invocant.

Since 1.75

unsubscribe example 1

  # given: synopsis

  package main;

  $example = $example->unsubscribe;

  # bless(..., 'Example')

unsubscribe example 2

  # given: synopsis

  package main;

  $example = $example->unsubscribe('on.execute');

  # bless(..., 'Example')

unsubscribe example 3

  # given: synopsis

  package main;

  $example = $example->subscribe('on.execute', sub {$example->{emitted_1} = [@_]});

  $example = $example->subscribe('on.execute', sub {$example->{emitted_2} = [@_]});

  $example = $example->subscribe('on.execute', sub {$example->{emitted_3} = [@_]});

  $example = $example->unsubscribe('on.execute');

  # bless(..., 'Example')

unsubscribe example 4

  # given: synopsis

  package main;

  my $execute = sub {$example->{execute} = [@_]};

  $example = $example->subscribe('on.execute', $execute);

  $example = $example->unsubscribe('on.execute', $execute);

  # bless(..., 'Example')

cpanm Venus

perl -MCPAN -e shell
install Venus