having a function run every ten seconds or when an input changes

Question

I have a simple react app where a user inputs a quantity and an api call is made to convert that value into an equivalent amount of a very unstable cryptocurrency, and that converted value is displayed on the screen.

Crucially, I want the converted value to be updated every ten seconds or when a user changes the input value.

I'm confused as to how to implement this. Any advice?

Answer 1

I don't know react, but in native JS it's pretty simple. Here's some code that sets your timer then clears and resets when you call an input change. Hope this is easily adaptable to react!

function cryptoTimer() {
  this.value = null
  this.timer = null
  this.getValue = () => {
    this.value = "some api response"
    console.log(this.value)
  }
  this.startTimer = () => {
    this.timer = setInterval(() => { this.getValue() }, 10000)
  }
  this.clearTimer = () => {
    clearInterval(this.timer)
  }
  this.inputChange = (elem) => {
    console.log('input changed, value is '+elem.value)
    this.clearTimer()
    this.init()
  }
  this.init = () => {
    this.getValue()
    this.startTimer()
  }
  this.init()
}

var timer = new cryptoTimer

<!-- some input on change action -->
<input onkeyup="timer.inputChange(this)" type="text" />

Answer 2

Here is an example

import React from "react";

export function App() {
  // Used to store the intervalId
  const timerRef = React.useRef();

  // Used to store the value in the input element
  const inputRef = React.useRef("");

  // This is for storing the transformed value you get from API
  const [transformedValue, setTransformedValue] = React.useState("");

  // In this function, you can make the request to the API and update
  // the transformed value. Remember to reset the interval.
  const transformValue = async () => {
    const input = inputRef.current;

    // Invoke your api instead
    const randomTransformation = `${input} ${new Date().toLocaleTimeString()}`;

    setTransformedValue(randomTransformation);

    resetInterval();
  };

  // This will just reset the interval
  const resetInterval = () => {
    if (timerRef.current) {
      clearInterval(timerRef.current);
    }
    timerRef.current = setInterval(transformValue, 10 * 1000);
  };

  return (
    <div className="container">
      <label htmlFor="input">Input</label>
      <input
        id="input"
        type="text"
        value={inputRef.current}
        onChange={(e) => {
          inputRef.current = e.target.value;
          transformValue();
        }}
      />

      <p>Transformed Value: {transformedValue}</p>
    </div>
  );
}