/usr/share/perl5/Mojo/EventEmitter.pm is in libmojolicious-perl 6.15+dfsg-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 | package Mojo::EventEmitter;
use Mojo::Base -base;
use Scalar::Util qw(blessed weaken);
use constant DEBUG => $ENV{MOJO_EVENTEMITTER_DEBUG} || 0;
sub catch { $_[0]->on(error => $_[1]) and return $_[0] }
sub emit {
my ($self, $name) = (shift, shift);
if (my $s = $self->{events}{$name}) {
warn "-- Emit $name in @{[blessed $self]} (@{[scalar @$s]})\n" if DEBUG;
for my $cb (@$s) { $self->$cb(@_) }
}
else {
warn "-- Emit $name in @{[blessed $self]} (0)\n" if DEBUG;
die "@{[blessed $self]}: $_[0]" if $name eq 'error';
}
return $self;
}
sub has_subscribers { !!shift->{events}{shift()} }
sub on { push @{$_[0]{events}{$_[1]}}, $_[2] and return $_[2] }
sub once {
my ($self, $name, $cb) = @_;
weaken $self;
my $wrapper;
$wrapper = sub {
$self->unsubscribe($name => $wrapper);
$cb->(@_);
};
$self->on($name => $wrapper);
weaken $wrapper;
return $wrapper;
}
sub subscribers { shift->{events}{shift()} ||= [] }
sub unsubscribe {
my ($self, $name, $cb) = @_;
# One
if ($cb) {
$self->{events}{$name} = [grep { $cb ne $_ } @{$self->{events}{$name}}];
delete $self->{events}{$name} unless @{$self->{events}{$name}};
}
# All
else { delete $self->{events}{$name} }
return $self;
}
1;
=encoding utf8
=head1 NAME
Mojo::EventEmitter - Event emitter base class
=head1 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;
=head1 DESCRIPTION
L<Mojo::EventEmitter> is a simple base class for event emitting objects.
=head1 EVENTS
L<Mojo::EventEmitter> can emit the following events.
=head2 error
$e->on(error => sub {
my ($e, $err) = @_;
...
});
This is a special event for errors, it will not be emitted directly by this
class but is fatal if unhandled.
$e->on(error => sub {
my ($e, $err) = @_;
say "This looks bad: $err";
});
=head1 METHODS
L<Mojo::EventEmitter> inherits all methods from L<Mojo::Base> and implements
the following new ones.
=head2 catch
$e = $e->catch(sub {...});
Subscribe to L</"error"> event.
# Longer version
$e->on(error => sub {...});
=head2 emit
$e = $e->emit('foo');
$e = $e->emit('foo', 123);
Emit event.
=head2 has_subscribers
my $bool = $e->has_subscribers('foo');
Check if event has subscribers.
=head2 on
my $cb = $e->on(foo => sub {...});
Subscribe to event.
$e->on(foo => sub {
my ($e, @args) = @_;
...
});
=head2 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) = @_;
...
});
=head2 subscribers
my $subscribers = $e->subscribers('foo');
All subscribers for event.
# Unsubscribe last subscriber
$e->unsubscribe(foo => $e->subscribers('foo')->[-1]);
# Change order of subscribers
@{$e->subscribers('foo')} = reverse @{$e->subscribers('foo')};
=head2 unsubscribe
$e = $e->unsubscribe('foo');
$e = $e->unsubscribe(foo => $cb);
Unsubscribe from event.
=head1 DEBUGGING
You can set the C<MOJO_EVENTEMITTER_DEBUG> environment variable to get some
advanced diagnostics information printed to C<STDERR>.
MOJO_EVENTEMITTER_DEBUG=1
=head1 SEE ALSO
L<Mojolicious>, L<Mojolicious::Guides>, L<http://mojolicio.us>.
=cut
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