@epnsproject/sdk-socket

socket

This package helps to connect to EPNS backend using websockets built on top of Socket.IO

How to use in your app?

Installation

  yarn add @epnsproject/sdk-socket ethers

or

  npm install @epnsproject/sdk-socket ethers 

Import in your file

import {
  createSocketConnection,
  EVENTS
} from '@epnsproject/sdk-socket';

first create a socket connection object

const epnsSDKSocket = createSocketConnection({
  user: 'eip155:5:0xab16a96d359ec26a11e2c2b3d8f8b8942d5bfcdb', // CAIP, see below
  env: 'staging',
  socketOptions: { autoConnect: false }
});

IMPORTANT: create the connection object in your app only when you have the user address available since its mandatory.

autoConnect: Generally if we don't pass autoConnect: false then the socket connection is automatic once the object is created. Now since we may or may not have the account address handy and wish to start the connection during instantiation so this option makes it easier for us to choose when we want to connect or not!

Allowed Options (params with * are mandatory)

Param	Type	Default	Remarks
user*	string	-	user account address (CAIP)
env	string	'prod'	API env - 'prod', 'staging', 'dev'
socketOptions	object	-	supports the same as SocketIO Options

connect the socket connection object

epnsSDKSocket.connect();

disconnect the socket connection object

epnsSDKSocket.disconnect();

subscribing to Socket Events

epnsSDKSocket.on(EVENTS.CONNECT, () => {

});

epnsSDKSocket.on(EVENTS.DISCONNECT, () => {

});

epnsSDKSocket.on(EVENTS.USER_FEEDS, (feedItem) => {
  // feedItem is the notification data when that notification was received
});

Supported EVENTS

EVENT name	When is it triggered?
EVENTS.CONNECT	whenever the socket is connected
EVENTS.DISCONNECT	whenever the socket is disconneted
EVENTS.USER_FEEDS	whenever a new notification is received by the user after the last socket connection
EVENTS.USER_SPAM_FEEDS	whenever a new spam notification is received by the user after the last socket connection

NOTE on Addresses:

In any of the below methods (unless explicitly stated otherwise) we accept either -

• CAIP format: for any on chain addresses We strongly recommend using this address format. (Example : ETH MAINNET address will be like eip155:1:0xab16a96d359ec26a11e2c2b3d8f8b8942d5bfcdb)

• ETH address format: only for backwards compatibility. (Example: 0xab16a96d359ec26a11e2c2b3d8f8b8942d5bfcdb)

A very basic example of using SDK sockets in a React App

import { useState, useEffect } from "react";
import { createSocketConnection, EVENTS } from '@epnsproject/sdk-socket';

const user = '0xD8634C39BBFd4033c0d3289C4515275102423681';
const chainId = 5;

const userCAIP = `eip155:${chainId}:${user}`;

function App() {
  const [sdkSocket, setSDKSocket] = useState<any>(null);
  const [isConnected, setIsConnected] = useState(sdkSocket?.connected);

  const addSocketEvents = () => {
    sdkSocket?.on(EVENTS.CONNECT, () => {
      setIsConnected(true);
    })

    sdkSocket?.on(EVENTS.DISCONNECT, () => {
      setIsConnected(false);
    })

    sdkSocket?.on(EVENTS.USER_FEEDS, (feedItem) => {
      /**
       * "feedItem" is the latest notification received
       */
      console.log(feedItem);
    })
  };

  const removeSocketEvents = () => {
    sdkSocket?.off(EVENTS.CONNECT);
    sdkSocket?.off(EVENTS.DISCONNECT);
  };

  const toggleConnection = () => {
    if (sdkSocket?.connected) {
      sdkSocket.disconnect();
    } else {
      sdkSocket.connect();
    }
  };


  useEffect(() => {
    if (sdkSocket) {
      addSocketEvents();
    }
    return () => {
      removeSocketEvents();
    };
  }, [sdkSocket]);

  useEffect(() => {
    const connectionObject = createSocketConnection({
      user: userCAIP,
      env: 'dev',
      socketOptions: { autoConnect: false }
    });


    setSDKSocket(connectionObject);

    return () => {
      if (sdkSocket) {
        sdkSocket.disconnect();
      }
    };
  }, []);

  return (
    <div>
      <h1>Socket Hello World</h1>

      <div>
        <p>Connection Status : {JSON.stringify(isConnected)}</p>

        <button onClick={toggleConnection}>{isConnected ? 'disconnect' : 'connect'}</button>
      </div>
    </div>
  );
}

export default App;

Please note connecting with sockets and maintaining the state of the connection object in your DAPP might have a different setup like first getting the user account and chainId and then connecting with socket. You can use React Context for state management.