Publishing & Subscribing to Platform Events

Lightning component uses empApi component to subscribe and receive event messages.

External clients can subscribe to events using CometD.

A custom CometD client can be implemented or Emp Connector can be used.

Platform events are sent by Salesforce to CometD clients sequentially in the order they are received.

Use case:

Events could be published from a Heroku application (via the REST API) or from a trigger on Chatter posts (via Apex). They should be received by a Lightning console app that should act as a subscriber (via the lightning:empApi component that uses a CometD client connection).

Solution Design:

For implementation details refer to https://github.com/JohnsonTitus/auraPubSubEvent.git

Use case:

When a sales order is created on an external web application, Salesforce user has to be notified and custom object record should be created.

Solution:

Using platform event, the external web app can publish it by using one of Salesforce's API - SOAP or REST or Bulk API.

Salesforce can subscribe to it using trigger on platform event object or process builder.