Pubsub - richardschneider/yappy GitHub Wiki

Publish/Subscribe, aka pubsub, is used for inter-communication in a loosely-coupled system. An event consists of an topic string and a message object. topic names are hierarchical and are rooted at /ecom.

Usage

The peers object contains the publish, subscribe and unsubscribe functions. The strong-pubsub package is used. We start out with just a local in-app pubsub for the time being. Then later scale-out to the internet to inform other server and even clients.

let peers = require('../lib/pubsub');
peers.publish('/ecom/api/change', req.originalUrl);

Caches

Caches need to be invalidated when a resource is modified. The crud layer will send a message containing the resource ID on modification. The cache can then remove its entry for the resource. Simple as.

Workflow

A Workflow can listen for an event and then kick-off some processing task.

For example, when a tenant is created it should receive an email to activate the account. Or when a purchase is authorised then the fulfillment system is engaged.

Events

TODO

topic	message