Infomaker im-infocaster-web-client

Prerequisites

You need to authorize yourself as infomaker with npm using a private key located in 1Password. The key can be found in the file 'JumpStart .env' in the Internal vault.

Installation

npm install @infomaker/im-infocaster-web-client --save

Basic Structure

The library supplies two web clients, using WebSocket and EventSource technologies. These clients can create normal InfoCaster sessions, and subscribe to InfoCaster Broadcasts.

When a message is received from InfoCaster to the session, or broadcast, the client will emit an event of either publish or broadcastPublish, for normal session and broadcast respectively.

In order to send messages to a session, the source doing the sending needs the session's webhookURL, or a broadcastId, and make simple http-requests to an InfoCaster endpoint detailed in the InfoCaster documentation.

Available Events

Name	Description
sessionInit	Triggers when the client has successfully created a connection with the InfoCaster endpoint
publish	Triggers when a source publishes a message to the session's webhookUrl
broadcastPublish	Triggers when a source publishes a message to the subscribed broadcast's publish-endpoint
error	Something went wrong
close	Connection to InfoCaster was closed for some reason

Usage

Subscribe/Unsubscribe to events

The client has three relevant functions for event handling: on, off, and clearEventHandlers.

To subscribe to an event it's as easy as infoCasterClient.on('publish', data => console.log(data)). In order to unsubscribe from an event, you need to have a named reference for your callback-function.

const callback = (data) => {
    console.log(data)
}

infoCasterClient.on('publish', callback)

infoCasterClient.off('publish', callback)

Select source

InfoCaster Web Client supports WebSocket and EventSource-sources and contain clients for both.

Communication for these clients are one-way, even on WebSocket. To send messages to the clients, use the webhookURL generated after the session has been initialized.

import {EventSourceClient, WebSocketClient} from '@infomaker/im-infocaster-web-client'

Or, if you prefer to use a different name:

import {EventSourceClient as InfoCasterClient} from '@infomaker/im-infocaster-web-client'

Override InfoCaster endpoint

By default, the clients are configured to talk to the production environment of InfoCaster, but if you want to change the base url to something else.

import {WebSocketClient, EventSourceClient} from '@infomaker/im-infocaster-web-client'

const infoCasterClient = new WebSocketClient('https://my-personal.lcc.infomaker.io')
const anotherClient = new EventSourceClient('https://my-personal.lcc.infomaker.io')

Sessions

Create an InfoCaster session and listen to updates

import {WebSocketClient} from '@infomaker/im-infocaster-web-client'

const infoCasterClient = new WebSocketClient('https://infocaster.lcc.infomaker.io', 'my-publisher', 'JWT-read-token', 'JWT-write-token')

infoCasterClient.on('sessionInit', (data) => {
    // Session is now active
})

// Receive all "publish"-type messages
infoCasterClient.on('publish', (data) => {
    console.log(data)
})

Publish a message to an InfoCaster session

An active session is required to publish a message.

import {WebSocketClient} from '@infomaker/im-infocaster-web-client'

const infoCasterClient = new WebSocketClient('https://infocaster.lcc.infomaker.io', 'my-publisher', 'JWT-read-token', 'JWT-write-token')

infoCasterClient.on('sessionInit', async (data) => {    
    // Session is now active
    await infoCasterClient.publish({foo: 'bar'})    
})

// Receive all "publish"-type messages
infoCasterClient.on('publish', (data) => {
    console.log(data) // {"payload": {"foo": "bar"}}
})

Fetch the current session's webhookURL

You might need to supply your backend with a way to send updates to your session; in that case, start a session and fetch that session's webhookUrl and use it on your backend.

import {WebSocketClient} from '@infomaker/im-infocaster-web-client'

const infoCasterClient = new WebSocketClient('https://infocaster.lcc.infomaker.io', 'my-publisher', 'JWT-read-token', 'JWT-write-token')

infoCasterClient.on('sessionInit', () => {
    console.log(infoCasterClient.webhookUrl)
})

Using channel for sessions

Sometimes it might be useful to differentiate messages on a single sessions by channel, sending status updates for different tasks on the same session connection for example. When using channels, the data supplied to the publish-event will contain a channel-property, which you can use to filter, group, or handle however you wish.

import {WebSocketClient} from '@infomaker/im-infocaster-web-client'

const infoCasterClient = new WebSocketClient('https://infocaster.lcc.infomaker.io', 'my-publisher', 'JWT-read-token', 'JWT-write-token')

infoCasterClient.on('sessionInit', async () => {    
    // Session is now active
    await infoCasterClient.publish({foo: 'bar'}, 'my-channel')    
})

// Receive all "publish"-type messages
infoCasterClient.on('publish', (data) => {
    console.log(data) // {"channel": "my-channel", "payload": {"foo": "bar"}}
})

Broadcasts

Subscribe to an InfoCaster Broadcast

An active session is required to subscribe to a broadcast. When a subscription is requested, your current session will be upgraded and start listening to that broadcast. Messages from that broadcast will trigger the broadcastPublish-event on the client.

import {WebSocketClient} from '@infomaker/im-infocaster-web-client'

const infoCasterClient = new WebSocketClient('https://infocaster.lcc.infomaker.io', 'my-publisher', 'JWT-read-token', 'JWT-write-token')

infoCasterClient.on('sessionInit', async () => {
    const broadcastId = 'my-broadcast-id'
    
    await infoCasterClient.subscribe(broadcastId)
})

Publish a message to an InfoCaster broadcast

An active session is required to publish a message.

import {WebSocketClient} from '@infomaker/im-infocaster-web-client'

const infoCasterClient = new WebSocketClient('https://infocaster.lcc.infomaker.io', 'my-publisher', 'JWT-read-token', 'JWT-write-token')

infoCasterClient.on('sessionInit', async (data) => {
    const broadcastId = 'my-broadcast-id'
    
    await infoCasterClient.subscribe(broadcastId)
    await infoCasterClient.broadcastPublish({foo: 'bar'}, 'my-broadcast-id')
})

// Receive all "broadcastPublish"-type messages
infoCasterClient.on('broadcastPublish', (data) => {
    console.log(data) // {"payload": {"foo": "bar"}}
})

Change publisher-id

The clients are by default sending and receiving messages to and from the publisher-id open. To send/receive using a different id, supply this id to the subscribe, and broadcastPublish-functions:

infoCasterClient.subscribe('my-broadcast-id', 'my-publisher-id')
infoCasterClient.broadcastPublish({foo: 'bar'}, 'my-broadcast-id', 'my-publisher-id')