NAME

       GraphQL::PubSub - publish/subscribe

SYNOPSIS

         use GraphQL::PubSub;
         my $pubsub = GraphQL::PubSub->new;
         $pubsub->subscribe('channel1', \&callback);
         $pubsub->publish('channel1', 1);
         $pubsub->unsubscribe('channel1', \&callback);

DESCRIPTION

       Encapsulates the publish/subscribe logic needed by GraphQL::Subscription.

METHODS

   subscribe($channel, \&callback[, \&error_callback])
       Registers the given callback on the given channel.

       The optional second "error" callback is called as a method on the object when an exception
       is thrown by the first callback. If not given, the default is for the subscription to be
       cancelled with "unsubscribe". The error callback will be called with values of the
       channel, the original callback (to enable unsubscribing), the exception thrown, then the
       values passed to the original callback. Any exceptions will be ignored.

   unsubscribe($channel, \&callback)
       Removes the given callback from the given channel.

   publish($channel, @values)
       Calls each callback registered on the given channel, with the given values.