DbListenerPg

DbListenerPg is a Router that LISTENs to a PostrgreSQL notification channel and forwards the incoming strings to registered processors: normally,

• DbServicePg
• DbQueuesRouterPg

instances.

Constructor

const {DbListenerPg, DbQueuesRouterPg} = require ('doix-db-postgresql')

const dbl = new DbListenerPg ({
    channel: 'hotline',
    db: {host: '127.0.0.1', port: 5432},
    logger
})

dbl.add (new DbServicePg (app1, {
  on: {
    start: function () {
//    this.rq = {type: 'mail', action: 'send', id: this.notification.payload)
//    this.rq = JSON.parse (this.notification.payload) // Generic example, be careful
    },
  },
}))

// dbl.add (new DbQueuesRouterPg (app2, {...}) 

await dbl.listen ()

The only parameter here is the bag of options.

Options

Name	Description
channel	The channel name to LISTEN on
db	options forwarded to the native constructor

Properties

Name	Description
pool	The DbPoolPg instance created according to db settings

Events

Name	Description
start	emitted at the end of the listen () method
notification	emitted for each notification, with a DbNotificationPg instance as payload
finish	emitted at the end of the close () method

Methods

listen ()

Starts listening to incoming notifications. For each of them, creates a DbNotificationPg instance and feeds it to the first matching processor, following the basic Router logic.

close ()

This asynchronous method makes the router stop listening to incoming requests.