crownstone-lib-nodejs-sse

SSE module for the nodejs libs. This is a small library to provide code with Server-Sent Events (SSE) events from the Crownstone cloud. SSE is a server push technology.

Overview of the nodejs modules

• https://github.com/crownstone/crownstone-lib-nodejs-core
• https://github.com/crownstone/crownstone-lib-nodejs-uart
• https://github.com/crownstone/crownstone-lib-nodejs-ble
• https://github.com/crownstone/crownstone-lib-nodejs-cloud
• https://github.com/crownstone/crownstone-lib-nodejs-sse

Installation

Run Yarn to install the dependencies.

yarn

Compile the ts files to get started:

npm run build

Usage

There are two small examples showing you how to get started in the ./examples folder.

// import the library
const sseLib = require("crownstone-sse")

// initialize the library
let sse = new sseLib.CrownstoneSSE();

// create a callback function to print incoming data
let eventHandler = (data) => {
  console.log("I got an event!", data);
}

// change these to match your Crownstone account credentials
let myCrownstoneEmailAddress = "<yourEmailAddressHere>";
let myCrownstonePassword     = "<yourPasswordHere>";

// There are other options to log in as well if you're not comfortable placing username/password data in code
// check the docs below for more info!

// create and start our async function.
(async function() {
  try {
    // we will login to the Crownstone cloud to obtain an accessToken.
    // It will be set automatically after successful login.
    console.log("Logging in...")
    await sse.login( myCrownstoneEmailAddress , myCrownstonePassword )
    
    // now that we have an accessToken, we can start the eventstream.
    console.log("Connecting to event server...")
    await sse.start(eventHandler);
    console.log("Let's get started!");
  }
  catch(err) {
    console.log("Something went wrong... :(");
  }
})()

There is a promise based example as well.

API

You can require the library like so:

// import the library
const sseLib = require("crownstone-sse")

// initialize the library
let sse = new sseLib.CrownstoneSSE();

or import it like so:

import { CrownstoneSSE } from "crownstone-sse"

let sse = new BluenetSSE();

In order to get the events, we require a Crownstone AccessToken. There are a few methods to facility this:

login(email: string, password: string) -> Promise<void>

Logs into the Crownstone Cloud and obtains the AccessToken. The token is then stored in the class and you're ready to call start().

loginHashed(email: string, sha1passwordHash: string) -> Promise<void>

If you don't want to put a plaintext password in code, you can also use a sha1 hash of your password. This method logs into the Crownstone Cloud and obtains the AccessToken. The token is then stored in the class and you're ready to call start().

setAccessToken(token: string)

You can also obtain the token yourself from https://my.crownstone.rocks. Use this to store it in the class and you're ready to call start().

Starting the event stream after you have ensured there is an accessToken in the lib, is done by calling start():

start(eventCallback: (SseEvent) => void) : Promise<void>

Connect to https://events.crownstone.rocks/sse and forwards all events to your callback.

stop()

Close the connection. Autoreconnect will be disabled as well. This is meant for destroying the SSE lib.

Events

There are a number of different events you can expect from this service.

System Events

These are used to notify you of the opening, closing and any errors with the event stream. The ping event is sent every 30 seconds with an incrementing counter. The format of these is:

interface SystemEvent {
  type:    "system",
  subType:  "TOKEN_EXPIRED" | "INVALID_ACCESS_TOKEN" | "NO_ACCESS_TOKEN" | "NO_CONNECTION" | "STREAM_START" | "STREAM_CLOSED",
  code:     number,
  message:  string,
}

interface PingEvent {
  type:    "ping",
  counter:  number,
}

Command Events

These notify actuators that they should so something.

A hub could use this to switch a Crownstone based on a call from the cloud.

• (LEGACY) The https://my.crownstone.rocks/api/Stones/id/setSwitchStateRemotely endpoint triggers the multiSwitch event.
• The https://my.crownstone.rocks/api/Stones/id/switch endpoint triggers the multiSwitch event.
• The https://my.crownstone.rocks/api/Spheres/id/switchCrownstones endpoint triggers the multiSwitch event.

interface MultiSwitchCrownstoneEvent {
  type:        "command",
  subType:     "multiSwitch"
  sphere:      SphereData,
  switchData:  CrownstoneSwitchCommand[],
}

// With subtypes:

interface SphereData {
  id:   string,
  uid:  number,
  name: string,
}

interface CrownstoneSwitchCommand {
  id:          string,
  name:        string,
  macAddress:  string,
  uid:         number,
  type:        "TURN_ON" | "TURN_OFF" | "PERCENTAGE"
  percentage?: number, // 0 .. 100
  switchState?: number // 0 .. 100 --> THIS IS LEGACY ONLY, DO NOT USE THIS, IT WILL BE REMOVED ON THE NEXT APP RELEASE
}

Presence events

When there is a change in user presence, these events are called. They are called on sphere enter, sphere exit, room enter and room exit for all users in the spheres you have access to.

// for sphere enter/exit events
interface PresenceSphereEvent {
  type:     "presence",
  subType:  "enterSphere" | "exitSphere"
  user:     UserData,
  sphere:   SphereData
}

// for room enter/exit events
interface PresenceLocationEvent {
  type:     "presence",
  subType:  "enterLocation" | "exitLocation"
  user:     UserData,
  sphere:   SphereData,
  location: LocationData,
}

// With subtypes:

interface SphereData {
  id:   string,
  uid:  number,
  name: string,
}

interface UserData {
  id:   string,
  name: string,
}

interface LocationData {
  id:   string,
  name: string,
}

Data change events

These events are called if Spheres, Users in spheres, Locations or Crownstones are added/deleted or updated. This does not respond to changes in power usage and switchstate.

interface DataChangeEvent {
  type:        "dataChange",
  subType:     "users"   | "spheres" | "stones" | "locations",
  operation:   "create"  | "delete"  | "update"
  sphere:      SphereData,
  changedItem: NameIdSet,
}

// When a Crownstone was switched, you can get this one instead:

interface SwitchStateUpdateEvent {
  type:        "switchStateUpdate",
  subType:     "stone",
  sphere:       SphereData,
  crownstone:   CrownstoneSwitchState,
}

// when the Crownstone's abilities have been updated
interface AbilityChangeEvent {
  type:        "abilityChange",
  subType:     "dimming"   | "switchcraft" | "tapToToggle",
  sphere:      SphereData,
  stone:       CrownstoneData,
  ability:     AbilityData
}


// When the sphereAuthorizationTokens have been cycled (only relevant for Crownstone hub)
interface SphereTokensUpdatedEvent {
  type:        "sphereTokensChanged",
  subType:     "sphereAuthorizationTokens",
  operation:   "update"
  sphere:      SphereData
}




// With subtypes:

interface SphereData {
  id:   string,
  uid:  number,
  name: string,
}

interface NameIdSet {
  id:   string,
  name: string,
}

interface CrownstoneData {
  id:   string,
  uid:  number,
  name: string,
  macAddress: string,
}
interface CrownstoneSwitchState extends CrownstoneData {
  percentage: number, // 0 .. 100
}
interface AbilityData {
  type: string,
  enabled: boolean,
  syncedToCrownstone: boolean,
}

Invitation change events

When someone is invited to a Sphere, or the invitation is revoked, these events are fired.

interface InvitationChangeEvent {
  type:        "invitationChange",
  operation:   "invited" | "invitationRevoked"
  sphere:      SphereData,
  email:       string,
}

// With subtypes:

interface SphereData {
  id:   string,
  uid:  number,
  name: string,
}

Cross platform

This can be used by NodeJS and React Native.

If you want to use it with NodeJS, you can use it as per the rest of the documentation.

For React Native, you can inject the RN environment modules to use:

const sha1 = require('sha-1'); // using sha-1 module from npm
import RNEventSource from 'react-native-event-source'
import { SSEGenerator } from "crownstone-sse/dist/CrownstoneSSE";

const logger = {
  error(...args) {},
  warn(...args) {},
  info(...args) {
    console.log(...args);
  },
  debug(...args) {
    console.log(...args);
  },
}

let options =  {
  log:         logger,
  sha1:        sha1,
  fetch:       fetch,
  EventSource: RNEventSource,
};

export const CrownstoneSSE = SSEGenerator(options);

let sse = new CrownstoneSSE();
// from here on, it is the same as the rest of the documentation.

License

Open-source license

This software is provided under a noncontagious open-source license towards the open-source community. It's available under three open-source licenses:

• License: LGPL v3+, Apache, MIT

Commercial license

This software can also be provided under a commercial license. If you are not an open-source developer or are not planning to release adaptations to the code under one or multiple of the mentioned licenses, contact us to obtain a commercial license.

• License: Crownstone commercial license

Contact

For any question contact us at https://crownstone.rocks/contact/ or on our discord server through https://crownstone.rocks/forum/.