TABLE OF CONTENTS

NAME

Mojo::EventEmitter - Event emitter base class

SYNOPSIS

package Cat;
use Mojo::Base 'Mojo::EventEmitter';

# Emit events
sub poke {
  my $self = shift;
  $self->emit(roar => 3);
}

package main;

# Subscribe to events
my $tiger = Cat->new;
$tiger->on(roar => sub {
  my ($tiger, $times) = @_;
  say 'RAWR!' for 1 .. $times;
});
$tiger->poke;

DESCRIPTION

Mojo::EventEmitter is a simple base class for event emitting objects.

EVENTS

Mojo::EventEmitter can emit the following events.

error

$e->on(error => sub {
  my ($e, $err) = @_;
  ...
});

Emitted for event errors, fatal if unhandled.

$e->on(error => sub {
  my ($e, $err) = @_;
  say "This looks bad: $err";
});

METHODS

Mojo::EventEmitter inherits all methods from Mojo::Base and implements the following new ones.

emit

$e = $e->emit('foo');
$e = $e->emit('foo', 123);

Emit event.

emit_safe

$e = $e->emit_safe('foo');
$e = $e->emit_safe('foo', 123);

Emit event safely and emit "error" event on failure.

has_subscribers

my $bool = $e->has_subscribers('foo');

Check if event has subscribers.

on

my $cb = $e->on(foo => sub {...});

Subscribe to event.

$e->on(foo => sub {
  my ($e, @args) = @_;
  ...
});

once

my $cb = $e->once(foo => sub {...});

Subscribe to event and unsubscribe again after it has been emitted once.

$e->once(foo => sub {
  my ($e, @args) = @_;
  ...
});

subscribers

my $subscribers = $e->subscribers('foo');

All subscribers for event.

# Unsubscribe last subscriber
$e->unsubscribe(foo => $e->subscribers('foo')->[-1]);

unsubscribe

$e = $e->unsubscribe('foo');
$e = $e->unsubscribe(foo => $cb);

Unsubscribe from event.

DEBUGGING

You can set the MOJO_EVENTEMITTER_DEBUG environment variable to get some advanced diagnostics information printed to STDERR.

MOJO_EVENTEMITTER_DEBUG=1

SEE ALSO

Mojolicious, Mojolicious::Guides, http://mojolicio.us.