Auto-Refresh and Cleanup Functions in React TypeScript: Keeping Your Web Application Efficient and Up-to-Date

Colton
3 min readFeb 21, 2023
Photo by Rui Alves on Unsplash

Auto-refresh in a React TypeScript Application

Auto-refresh is a useful feature in web applications that allows the application to fetch new data from the server automatically without the user needing to refresh the page manually. In a React TypeScript application, you can implement auto-refresh using the useEffect hook and the setInterval method.

To implement auto-refresh, you can use the useEffect hook to make an API call to fetch data from the backend API and then use the setInterval method to delay the next call to the API by a certain amount of time. When the component unmounts or when the dependencies of the hook change, you can use the returned function to clear any resources that were set up in the effect.

Here’s an example code snippet that demonstrates how to implement auto-refresh in a React TypeScript application:

import React, { useState, useEffect } from 'react';

interface Data {
// Define the type of data you expect to receive from the API
// Example:
id: number;
name: string;
// ...
}

const App: React.FC = () => {
const [data, setData] = useState<Data | null>(null);

useEffect(() => {
const fetchData = async () => {
const response = await fetch('https://example.com/api/data');
const json = await response.json();
setData(json);
};

fetchData(); // Fetch data initially

const intervalId = setInterval(() => {
fetchData(); // Fetch data every 2 minutes
}, 120000);

return () => clearInterval(intervalId);
}, []); // Run useEffect only once when the component mounts

return (
<div>
{/* Render the data */}
</div>
);
};

In this example, the useEffect hook is used to run the fetchData function initially when the component mounts and then every 2 minutes using the setInterval method. The intervalId is stored in a variable so that it can be cleared when the component unmounts using the clearInterval method. The data returned from the API is stored in the data state using the setData function, and it can be rendered in the component's return statement.

The Cleanup Function

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Colton

A software engineer who is always at a high level of passion with new techs and a strong willing to share with what I have learned.