Socket.io and local storage

Question

I have made a chat app using socket.io and node.

• Scenario- Now need to store messages into localStorage of browser , just before socket gets disconnected (disconnect event is emited) and fetch / sync data to that local storage once user reconnects.

• Issue- But problem is that if I am emiting some event from inside of "disconnect" handler back to client and there on client side inside handler for this event localStorage.setItem('msgText', msg). Its not saving to local storage.(As on disconnect event client has already been disconnected)

• Used node-localstorage module to set data in local storage of browser, while painting view when user logs-in , but its not saving data to localStorage of browser

const LocalStorage = require('node-localstorage').LocalStorage let localStorage = new LocalStorage('./scratch') localStorage.setItem('name_test', 'tom') console.log(localStorage.getItem('name_test'))

Any suggestion , as how to tackle the scenario / issue is most appreciated on this ?

Answer 1

When you fire the disconnect event, you could set your local storage just before. If I am understanding correctly I believe the below example should work for you

function disconnectUserFromChat() {
  return new Promise(function(resolve, reject) {
    try {
      localStorage.setItem('key', 'Value')
      resolve()
    } catch(error) {
      reject(error)
    }
  })
})

disconnectUserFromChat()
  .then(function() {
    socket.on('disconnect', function() {
      console.log('Disconnected')
    })
  })