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how do i stop Timeout from running if condition changes/updates?

code:

const isEnd = false; // Whenever event triggers the value will be false.

if (isEnd) {
console.log('Manual End')
} else {
setTimeout(() => {
console.log('Automatic End')
}, 30000);
}

Issue:

This is event, so when the event triggers isEnd value will be false and when event triggers it has 30 seconds to update value to true.
isEnd value can be changed to true, Anytime by the user/me in running app or without restarting.
If isEnd values changes to true in a given time (30 seconds) I want to log manual end and remove setTimeout and don't log amything inside setTimeout function.

I tried until now:

tried if/else, switch, while, do while.
tried to clearTimeout and a lot different ways but can't remove setTimeout

import { setTimeout as wait } from 'node:timers/promises';

  let timerId;
  switch (isEnded) {
    case true:
      console.log('Manual Ended');

      clearTimeout(timerId);
      break;
    case false:
      clearTimeout(timerId);
      timerId = wait(30000).then(() => {
        console.log('Automatic Ended');
      });
      break;
  }

excepted:

if condition updates log manual End
if condition doesn't changes it should only log Automatic End
should log only any one of two logs.

about 4 years ago · Juan Pablo Isaza

2 Respuestas

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Answer 1 · 2022-06-30T09:48:36.946Z

instead of trying to trigger changes in the value of isEnd you can try a different approach,

you can directly clearTimeOut whenever you or the user change the value of isEnd

for example instead of doing this

const isEnd = false 
let timerId;

buttn.addEventListener("click", () => {
  isEnd = true
})



if (isEnd) {
  console.log('Manual End')
  clearTimeOut(timerId)
} else {
timerId = setTimeout(() => {
  console.log('Automatic End')
}, 30000);
}

do this

let timerId =  setTimeout(automaticEnd, 30000);
// when the user make a manual break 
cancelButton.addEventListener("click", () => {
  manualEnd()
})



function automaticEnd() {
  console.log('Automatic End')
}

function manualEnd() {
  clearTimeOut(timerId)
  console.log("manualEnd")
}

Answer 2 · 2022-06-30T09:48:36.954Z

You could try a somehow more complex but interesting and elegant approach, using an object structure for your condition isEnd, and using object getters and setters to subscribe to a custom listener for object property changes:

This works perfectly in browser console (you can launch the snippet), should work in Node as well:

// Object of your condition
const isEnd = {
  _value: false, // this is the value of the condition
  valueListener: function(val) {}, // defining a generic listener

  // getter
  get value() {
    return this._value;
  },

  // setter
  set value(val) {
    this._value = val;
    this.valueListener(val); // when changing the value, the function valueListener is called with the new value set
  },

  // method to pass an actual listener function to valueListener property
  listenTo: function(listener) {
    this.valueListener = listener;
  }
};

console.log("START: isEnd has a value of: " + isEnd.value);


// timer of 20 seconds
const timer = setTimeout(() => {
  console.log('Timer expired');
}, 20000)

// you subscribe to the isEnd.value change, passing an actual listener function
// this function should contain the logic to execute
// based on the new condition value
// (like clearing the timer)
isEnd.listenTo(function(val) {
  console.log('new value for isEnd is now: ' + val);

  if (val === true) {
    if (timer) {
      clearTimeout(timer);
      console.log('timer cleared!');
    }
  }

  if (val === false) {
    console.log('HEY... false again!');
  }
})

// timer of 5 seconds that simulates
// the condition changing after 5 seconds
setTimeout(function() {
  isEnd.value = true;
}, 5000)

// timer of 10 seconds that simulates
// the condition changing after
// another 5 seconds
setTimeout(function() {
  isEnd.value = false;
}, 10000)

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123

how do i stop Timeout from running if condition changes/updates?

2 Respuestas

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Encuentra empleos remotos

Andres GPT