@flatfile/listener-driver-pubsub

This document provides instructions on how to use the PubSubDriver class, a utility for the @flatfile/listener package.

Introduction

PubSubDriver is an EventDriver that uses a real-time messaging system to listen for events. It uses the Flatfile API to authenticate, and automatically handles re-authentication if necessary.

The driver requires a scope, which can either be an environment or space ID. It also sets up an interceptor for Axios, which helps in debugging HTTP requests.

Usage

Import the necessary dependencies:

``javascript
import { EventDriver } from '@flatfile/listener'
import { PubSubDriver } from './PubSubDriver'
`

Create a new PubSubDriver instance, passing the scope as a string (either an environment ID or a space ID):

`javascript
const pubSubDriver = new PubSubDriver('your-environment-or-space-id')
`

Start the driver:

`javascript
pubSubDriver.mount(instanceOfListenerClient)
pubSubDriver.start()
`

Please note that the start method is asynchronous and returns a Promise.

The PubSubDriver instance will automatically subscribe to the event channel corresponding to the provided scope, and will start processing events as they come in.

It also handles connection status events, logging successful connections and errors, and automatically reauthenticating if necessary.

Logging

The PubSubDriver uses the Debugger from the @flatfile/utils-debugger package to log events. Log entries include successful connections, errors, and event processing info.

For example, when the driver successfully connects to the event stream, it logs a success message with the scope:

`shell
✅ Connected to event stream for scope your-environment-or-space-id
`

Please refer to the @flatfile/utils-debugger package documentation for more information on how logging works.

Axios Interceptor

The axiosInterceptor from @flatfile/utils-debugger is automatically set up when the PubSubDriver is started, which can help with debugging HTTP requests made using Axios.

Please refer to the @flatfile/utils-debugger package documentation for more information on how the Axios interceptor works.

Errors

If the scope is not provided during the initialization of PubSubDriver, an error is thrown:

`shell
Error: scope is required (must be an environment or space id)
`

Please ensure that a valid scope is provided when creating a new PubSubDriver` instance.