how to use cookies in react js with code examples 2

Introduction

Cookies are small pieces of data that are stored on the client-side, mainly the browser, by a website for various purposes such as authentication, session management, remembering the preferences of the user, etc. In React JS, there are various libraries available that can help in implementing the cookie functionality such as 'react-cookie', 'js-cookie', etc. In this article, we will explore how to use cookies in React JS with code examples using the 'js-cookie' library.

Installation

The first step in using cookies in React JS is to install the 'js-cookie' library. It can be installed by running the command "npm install js-cookie" in the terminal.

Code Examples

1. Setting a Cookie

The first example shows how to set a cookie in React JS using the 'js-cookie' library. The 'set' method of the 'Cookies' object is used to set the cookie. The method takes two parameters – the name of the cookie and its value.

import React from 'react';
import Cookies from 'js-cookie';

function App() {
const handleClick = () => {
Cookies.set('username', 'John Doe');
};

return (

);
}

export default App;

In the above example, the 'handleClick' function sets a cookie with the name 'username' and value 'John Doe' when the button is clicked. The cookie will be available on the client-side until it expires or is manually deleted.

2. Getting a Cookie

The next example shows how to get a cookie from the browser using the 'js-cookie' library. The 'get' method of the 'Cookies' object is used to get the cookie. The method takes the name of the cookie as a parameter.

import React from 'react';
import Cookies from 'js-cookie';

function App() {
const [username, setUsername] = React.useState('');

const handleClick = () => {
const name = Cookies.get('username');
setUsername(name);
};

return (

);
}

export default App;

In the above example, the 'handleClick' function gets the value of the cookie with the name 'username' and updates the 'username' state variable. The value of the cookie is displayed in the paragraph element.

3. Checking if a Cookie Exists

The following example shows how to check if a cookie exists on the client-side using the 'js-cookie' library. The 'get' method of the 'Cookies' object is used to get the cookie. If the cookie is not present, the method returns undefined.

import React from 'react';
import Cookies from 'js-cookie';

function App() {
const [isLoggedIn, setIsLoggedIn] = React.useState(false);

const handleClick = () => {
const token = Cookies.get('token');
if (token) {
setIsLoggedIn(true);
} else {
setIsLoggedIn(false);
}
};

return (

);
}

export default App;

In the above example, the 'handleClick' function checks if a cookie with the name 'token' exists on the client-side. If the cookie is present, the 'isLoggedIn' state variable is set to true, otherwise, it is set to false. The value of the 'isLoggedIn' variable is displayed in the paragraph element.

Conclusion

In this article, we explored how to use cookies in React JS with code examples using the 'js-cookie' library. We learned how to set a cookie, get a cookie, and check if a cookie exists on the client-side. Cookies are an important aspect of web development and their proper utilization in React JS can help in building efficient and secure applications.

I can provide more information on the previous topics I covered in the article about using cookies in React JS with code examples.

Installation

Before we can start using the 'js-cookie' library in React JS, we need to install it first. This can be done using the command "npm install js-cookie." Once installed, we can import it in our React components using the 'import' statement as shown in the code examples.

Setting a Cookie

Setting a cookie in React JS using the 'js-cookie' library is pretty straightforward. We need to use the 'set' method of the 'Cookies' object which takes the name of the cookie and its value as parameters. The method can also take additional parameters such as the expiration time of the cookie, its path, domain, and whether it should be sent over secure connections only. The cookie that we set will be stored on the client-side until it expires or is manually deleted.

Getting a Cookie

Once we have set a cookie, we can retrieve its value using the 'get' method of the 'Cookies' object. This method takes the name of the cookie as a parameter and returns its value. If the cookie is not present, the method returns undefined. We can then store the value of the cookie in a state variable or use it in any other way we like.

Checking if a Cookie Exists

Sometimes, we need to perform certain actions depending on whether a cookie exists or not. For example, we may want to redirect the user to the homepage if they are already logged in and have a session cookie. To check if a cookie with a particular name exists, we can use the 'get' method of the 'Cookies' object and check if it returns a value or undefined. If the method returns a value, it means that the cookie exists and we can perform the required actions accordingly.

Conclusion

Using cookies in React JS is a powerful way to store and retrieve information on the client-side. Cookies are commonly used for purposes such as session management, authentication, and remembering user preferences. By using the 'js-cookie' library in React JS, we can easily add cookie functionalities to our applications.

Popular questions

Sure, here are five questions and their answers related to the article about using cookies in React JS with code examples:

1. What is a cookie?
   Answer: A cookie is a small piece of data that is stored on the client-side, usually in the browser, by a website for various purposes such as authentication, session management, etc.

2. What is the 'js-cookie' library used for in React JS?
   Answer: The 'js-cookie' library is a popular library used in React JS for implementing cookie functionalities such as setting, getting, and checking cookies on the client-side.

3. How can we install the 'js-cookie' library in a React project?
   Answer: We can install the 'js-cookie' library in a React project by running the command "npm install js-cookie" in the terminal.

4. How do we set a cookie in React JS using the 'js-cookie' library?
   Answer: We use the 'set' method of the 'Cookies' object provided by the 'js-cookie' library to set a cookie in React JS. The method takes the name of the cookie and its value as parameters.

5. What is the difference between Session Cookies and Persistent Cookies?
   Answer: Session Cookies are temporary cookies that are stored on the client-side only until the browser window is closed, while Persistent Cookies remain on the client-side for a specified period of time, even after the browser window is closed. Persistent Cookies can be set with an expiration date or time.

Tag

React Cookies