fastify-pg-pubsub

Minimal pub/sub for fastify servers using postgres.

Install

fastify-pg-pubsub requires fastify-postgres.

npm install fastify-postgres fastify-pg-pubsub

Usage

The fastify-pg-pubsub plugin decorates the server instance with a pubsub property.

fastify.register(require('fastify-postgres'))
fastify.register(require('fastify-pg-pubsub'))
fastify.register(async function (server) {
  server.pubsub.on('some_channel', (message) => {
    console.log(message)
  })
  await server.pubsub.subscribe('some_channel')
  // ... elsewhere ...
  await server.pubsub.publish('some_channel', 'message')
  // ...
  await server.pubsub.unsubscribe('some_channel')
})

API

fastify.register(require('fastify-pg-pubsub'))

Register the plugin. There are no options. It will request a postgres connection from fastify-postgres.

fastify.pubsub

The pubsub property is an EventEmitter. Listen for events using the typical .on, .once methods.

fastify.pubsub.subscribe(channel)

Subscribe to a channel to start receiving messages from it. Returns a Promise that resolves when the subscription is added in postgres.

The channel name can contain a-z, 0-9, underscores, and dashes.

fastify.pubsub.unsubscribe(channel)

Unsubscribe from a channel to stop receiving messages from it. Returns a Promise that resolves when the subscription is removed in postgres.

The channel name can contain a-z, 0-9, underscores, and dashes.

fastify.pubsub.publish(channel, message)

Publish a message to a channel. You do not need to be subscribed to a channel to publish to it. The message must be a string. Use JSON.stringify or some other serialization mechanism before publishing other things.

The channel name can contain a-z, 0-9, underscores, and dashes.

License

Apache-2.0