@service-broker/webclient

Browser ESM client library for communicating with a Service Broker

Install

npm install @service-broker/webclient

Connect

Connect to the Service Broker at the specified WebSocket URL.

import { ServiceBroker } from "@service-broker/webclient"

const sb = new ServiceBroker("wss://sb.mydomain.com")

Request

Send a service request. The broker will select a qualified provider based on service name and requested capabilities. The parameter request contains the actual message that'll be delivered to the service provider.

interface Message {
  header: {
    from: string      // the endpointId of the sender
    to: string        // the endpointId of the recipient
  },
  payload: string     // the message payload, usually JSON
}

sb.request(
  service: {
    name: string,
    capabilities?: string[]
  },
  request: Message,
  timeout?: number
): Promise<Message>

Notify

A notification is like a request except no response will be sent back.

sb.notify(
  service: {
    name: string,
    capabilities?: string[]
  },
  notification: Message
): Promise<void>

RequestTo

Send a service request directly to an endpoint.

sb.requestTo(
  endpointId: string,
  serviceName: string,
  request: Message,
  timeout?: number
): Promise<Message>

NotifyTo

Send a notification directly to an endpoint.

sb.notifyTo(
  endpointId: string,
  serviceName: string,
  notification: Message
): Promise<void>

SetServiceHandler

The requestTo and notifyTo methods can be used to send direct messages to an endpoint. For example, a chat service provider may publish a client's endpointId to other clients and allow them to send direct messages to one another.

This method sets a handler for incoming requests and notifications.

sb.setServiceHandler(
  serviceName: string,
  handler: (request: Message) => Message|void|Promise<Message|void>
): void

Publish/Subscribe

sb.publish(
  topic: string,
  text: string
): Promise<void>

sb.subscribe(
  topic: string,
  handler: (text: string) => void
): Promise<void>

sb.unsubscribe(
  topic: string
): Promise<void>