Provided by: libmojo-pg-perl_4.04-1_all 

NAME
Mojo::Pg::PubSub - Publish/Subscribe
SYNOPSIS
use Mojo::Pg::PubSub; my $pubsub = Mojo::Pg::PubSub->new(pg => $pg); my $cb = $pubsub->listen(foo => sub { my ($pubsub, $payload) = @_; say "Received: $payload"; }); $pubsub->notify(foo => 'I ♥ Mojolicious!'); $pubsub->unlisten(foo => $cb);
DESCRIPTION
Mojo::Pg::PubSub is a scalable implementation of the publish/subscribe pattern used by Mojo::Pg. It is based on PostgreSQL notifications and allows many consumers to share the same database connection, to avoid many common scalability problems.
EVENTS
Mojo::Pg::PubSub inherits all events from Mojo::EventEmitter and can emit the following new ones. reconnect $pubsub->on(reconnect => sub { my ($pubsub, $db) = @_; ... }); Emitted after switching to a new database connection for sending and receiving notifications.
ATTRIBUTES
Mojo::Pg::PubSub implements the following attributes. pg my $pg = $pubsub->pg; $pubsub = $pubsub->pg(Mojo::Pg->new); Mojo::Pg object this publish/subscribe container belongs to.
METHODS
Mojo::Pg::PubSub inherits all methods from Mojo::EventEmitter and implements the following new ones. json $pubsub = $pubsub->json('foo'); Activate automatic JSON encoding and decoding with "to_json" in Mojo::JSON and "from_json" in Mojo::JSON for a channel. # Send and receive data structures $pubsub->json('foo')->listen(foo => sub { my ($pubsub, $payload) = @_; say $payload->{bar}; }); $pubsub->notify(foo => {bar => 'I ♥ Mojolicious!'}); listen my $cb = $pubsub->listen(foo => sub {...}); Subscribe to a channel, there is no limit on how many subscribers a channel can have. Automatic decoding of JSON text to Perl values can be activated with "json". # Subscribe to the same channel twice $pubsub->listen(foo => sub { my ($pubsub, $payload) = @_; say "One: $payload"; }); $pubsub->listen(foo => sub { my ($pubsub, $payload) = @_; say "Two: $payload"; }); notify $pubsub = $pubsub->notify('foo'); $pubsub = $pubsub->notify(foo => 'I ♥ Mojolicious!'); $pubsub = $pubsub->notify(foo => {bar => 'baz'}); Notify a channel. Automatic encoding of Perl values to JSON text can be activated with "json". reset $pubsub->reset; Reset all subscriptions and the database connection. This is usually done after a new process has been forked, to prevent the child process from stealing notifications meant for the parent process. unlisten $pubsub = $pubsub->unlisten('foo'); $pubsub = $pubsub->unlisten(foo => $cb); Unsubscribe from a channel.
SEE ALSO
Mojo::Pg, Mojolicious::Guides, <http://mojolicious.org>.