Issue

This Content is from Stack Overflow. Question asked by nihar saini

I am trying to store the button click logs user level so that I can use them somewhere in my project can you help me and tell how I can do that thing user level and set them using an api and get them when ever needed I am using svelte for my front end (store the log using firebase or something similar).user level means for each user different data will be saved and and I can use userid to get the details for the user by using userid

Solution

I suggest some decorator pattern applied to the event handler of interest.

Suppose you have a button and you want to log the on:click event. You can decorate the handleClick event handler with a decorator named monitor.

<script>
import { getContext, onMount } from "svelte"

const monitor = getContext("monitor")

function handleClick(event) {
  // do stuff
}

</script>

<button on:click={monitor(handleClick)}>Click me</button>

Now in your root <App /> component, you should initialize monitor decorator and set it into context.

<script> // App.svelte
import { setContext } from "svelte"
import { Login } from "./components/Login.svelte"

let userId = null
const setUserId = (id) => { userId = id }

// the decorator wraps the original eventHandler
// and smuggles in some report logic
function monitor(eventHandler) {
  return function decoratedEventHandler() {
    // if we have the userId, we can start to report event logs
    if (userId) {
      const event = arguments[0]
      // impl report as you needed
      // it can simply be a HTTP POST to some backend API
      // I definitely suggest add some throttle mechanism into it
      report(userId, event) 
    }
    eventHandler.apply(this, arguments)
  }
}

setContext("monitor", monitor)

onMount(() => {
  // if you store userId in cookie,
  // you parse the cookie and restore it
  userId = getUserIdFromCookie(document.cookie)
})

</script>

<!-- 
or maybe your Login component has some special logic
to get userId from backend
-->

<Login updateUserId={setUserId} ></Login>

This Question was asked in StackOverflow by nihar saini and Answered by hackape It is licensed under the terms of CC BY-SA 2.5. - CC BY-SA 3.0. - CC BY-SA 4.0.