tw-pubsub

Taskworld Pubsub module

Usage no npm install needed!

<script type="module">
  import twPubsub from 'https://cdn.skypack.dev/tw-pubsub';
</script>

README

TW-Pubsub

Simple redis-pubsub system

Installation

npm install tw-pubsub

Initialize pub-sub

You can initialize by calling pubsub.init(ChannelName). Channel name is set to default as TW_MESSAGE_BUS

You will get a channel after init pubsub system, which you can publish or subscribe to topics.

Example:

const TwPubSub = require('tw-pubsub')
TwPubSub.pubsub.init(channel => {
  channel.publish('topic', { payload: 'some payload' })
  channel.subscribe('topic', (message) => {
    // Do some thing with message
  })
})

Message schema is defined as:

  • sourceId = service name
  • payloadId = unique id for this payload (use for reference)
  • topic
  • payload
  • type = type of message. Right now we have 'request', 'response', 'others', 'errors'
  • requestId = for request-response paradigm, identified payloadId which you will response to

Endpoints helper

If you want to use library as request-response paradigm, you can use endpoint helper to create endpoint for topic

Example:

TwPubSub.createPubsubEndpoint({
  topic: 'test1',
  handler: (message) => {
    return new Promise((resolve, reject) => {
      resolve('hello world')
    })
  },
  channel
})

createPubSubEndpoint require 3 options:

  • topic = topic you want to handle
  • handler = handle function (must be promise based)
  • channel = channel object of pubsub system you want to create endpoint.

Request helper

You can create request to endpoint by using request helper.

Example:

TwPubSub.request('test-endpoint', { payload: 'test-payload' }, channel).then(message => {
  // Do something with message
})

You will get response from that endpoint, in message schema format.