tag with the content of Dashboard: Repeat the same steps for Preferences. When you do, the browser will reload and youll find your basic components: Check each of the routes. Be sure that you are importing App.css so that you can apply the styles. Wrap the

and the

in a

with a className of login-wrapper. nano src/components/Dashboard/Dashboard.js. Facebook and other individual developers/companies keep it up to date. Many web applications are a mix of public and private pages. You will be fetching data from APIs using React. The callback takes a req argument, which contains the request data and a res argument that handles the result. If you have any doubts or queries regarding the courses or this article, feel free to drop them in the comments section below. Import express, then call express() to create a new app and save the output to a variable called app. PMP, PMI, PMBOK, CAPM, PgMP, PfMP, ACP, PBA, RMP, SP, and OPM3 are registered marks of the Project Management Institute, Inc. Hi, first of all I want to see that great article!! Good stuff. Or the token can be an object too? The route /dashboard should be a protected page and should not be viewable by an unauthenticated user. To begin, make a new directory for the Login component: Create a basic form with a submit and an for the username and the password. In this step, youll create a local API to fetch a user token. Place getToken before the state declaration, then initialize useState with getToken. This is dated and broken. Now you can refresh your page and the user will remain logged in. That means youll need to convert the userToken from an object to a string using the JSON.stringify function. Using Node.js and the Express web framework, we can easily establish a server. You also learned about how sessionStorage and localStorage affect the users ability to start new sessions without login. Open the component: Now that you have some components, you need to import the components and create routes inside of App.js. Finally, construct a handleSubmit form submission handler that will provide the username and password to loginUser. There are two versions available: a browser version and a native version that can be used with React Native. When you fetch the token in your browser, you are making a GET request, but when you submit the login form you will be making a POST request. Obtaining data refers to more than just retrieving data from an API's endpoint; it also refers to the logic of a React component. *Lifetime access to high-quality, self-paced e-learning content. Use the onSubmit event handler on the form to call handleSubmit. Youll call the API from the Login component and save the token to memory on success. Each storage solution offers distinct advantages and disadvantages. Replace the contents with a class of .wrapper with padding of 20px: Save and close the file. We'll need a Node.js development environment; this guide was tested with version 10.22.0 of Node.js and version 6.14.6 of npm. Youll start by installing React Router and creating components to represent a full application. By the end of this step, youll have a basic application that will render a login page when a user is not logged into the application. There are two different versions: a web version and a native version for use with React Native. In this step, you saved tokens with sessionStorage and localStorage. Be sure to set the input type for the password to password: For more on forms in React, check out the tutorial How To Build Forms in React. Installing React Router and designing components to represent a comprehensive application are the first steps. In a new terminal window or tab, start the server: You will receive a response indicating that the server is starting: Visit http://localhost:8080/login and youll find your JSON object. You could leave the function as a standard, named function, but it can be easier to read when top-level functions are standard and internal functions are arrow functions. In this example, youll add the service directly to the component. Unlike sessionStorage, localStorage will save data even after the session ends. For a detailed introduction to creating an Express server, see the tutorial Basic Express Server in Node.js. Then open Dashboard.js in a text editor. Next, add an

tag asking the user to log in. This will fetch the token and set it as the initial state: Next, copy the setToken function from App.js. Remove the getToken and setToken functions. They operate as a link between the standard components that render the user interface and the logic that makes the UI interactive and dynamic. Notice that you do not need to import React since you will have no JSX in the file. Import useState from react, then call useState and set return values to token and setToken: Import the Login component. CodeIgniter: Getting Started With a Simple Example, How To Install Express, a Node.js Framework, and Set Up Socket.io on a VPS, auth-tutorial/src/components/Dashboard/Dashboard.js, auth-tutorial/src/components/Preferences/Preferences.js, auth-tutorial/src/components/Login/Login.js, auth-tutorial/src/components/Login/Login.css, auth-tutorial/src/components/App/useToken.js, DigitalOcean Kubernetes: new control plane is faster and free, enable HA for 99.95% uptime SLA, 'API is running on http://localhost:8080/login', Step 3 Storing a User Token with sessionStorage and localStorage, Using localStorage to Save Data Across Windows, 1/21 How To Set Up a React Project with Create React App, 2/21 How To Create React Elements with JSX, 3/21 How To Create Custom Components in React, 4/21 How To Customize React Components with Props, 5/21 How To Create Wrapper Components in React with Props, 7/21 How To Manage State on React Class Components, 8/21 How To Manage State with Hooks on React Components, 9/21 How To Share State Across React Components with Context, 10/21 How To Debug React Components Using React Developer Tools, 11/21 How To Handle DOM and Window Events with React, 13/21 How To Handle Async Data Loading, Lazy Loading, and Code Splitting with React, 14/21 How To Call Web APIs with the useEffect Hook in React, 15/21 How To Manage State in React with Redux, 16/21 How To Handle Routing in React Apps with React Router, 17/21 How To Add Login Authentication to React Applications, 18/21 How To Avoid Performance Pitfalls in React with memo, useMemo, and useCallback, 19/21 How To Deploy a React Application with Nginx on Ubuntu 20.04, 20/21 How To Deploy a React Application to DigitalOcean App Platform, How to Install Node.js and Create a Local Development Environment on macOS, How To Call Web APIs with the useEffect Hook in React, How To Handle Routing in React Apps with React Router, React Router to redirect if the user is not logged in, Next in series: How To Avoid Performance Pitfalls in React with memo, useMemo, and useCallback ->. app.listen(8080, () => console.log('API is running on http://localhost:8080/login')); The file should be saved and closed. setUserName(e.target.value)} />, setPassword(e.target.value)} />. Open App.js: In Step 3, youll explore options for storing the token. When you log in, the browser saves the token, but you still see the login page. Inside of the Switch, add a Route with a path for each component: The final step is to add some padding to the main

so your component is not directly at the edge of the browser. Make sure that your local API is still running, then open a browser to http://localhost:3000/dashboard. A container component's most typical role is to obtain data. The methods you call will be the same: Save the file. If you visit http://localhost:3000/dashboard, youll find the dashboard page: Your routes are working as expected, but there is a slight problem. Create the loginUser async function. You can use authentication to manage which users have access to which pages. If you would like to read more React tutorials, check out our React Topic page, or return to the How To Code in React.js series page. Also, be sure to include our component in the header. However, each team will be different. We also learned how sessionStorage and localStorage affect the ability of a user to start new sessions without logging in. The user will be responsible for explicitly logging out. To convert to localStorage, open useToken.js: Then change every reference of sessionStorage to localStorage. 2022 DigitalOcean, LLC. However, there is still an issue. Finally, import Login.css: Now that you have a basic Login component, youll need to add some styling. For example, you can create a new route for a login page and use React Router to redirect if the user is not logged in. You can find detailed information about uncontrolled components in How To Build Forms in React. So, we must have good understanding of API. Add in a handler for the /login path. btw awesome guide, thank you! Create a< h3> tag in Dashboard.js with the following content: Follow the same procedure for Preferences. We also made a custom Hook to make a component re-render happen and to shift component logic to a different function. Choose one style and stick with it. Call res.send with a JavaScript object containing a token: Finally, run the server on port 8080 using app.listen: Save and close the file. We then use the setEmail and setPassword procedures to save what the user fills in e.target.value and tie the state to our two fields in the form. Call handleSubmit using the onSubmit event handler on the : Note: In a full application, youll need to handle situations where the component unmounts before a Promise resolves. sessionStorage belongs only to the specific window session. To start, install express. This method takes a key as an argument and returns the string value. The program comprises a variety of software development courses, ranging from the fundamentals to advanced topics. The browser will reload, and we'll see the basic components. There are several options for storing tokens. Explained with Examples, Learn Git Command, Angular, NodeJS, Maven & More, In Partnership with HIRIST and HackerEarth, Cloud Architect Certification Training Course, DevOps Engineer Certification Training Course, Big Data Hadoop Certification Training Course, Data Science with Python Certification Course, AWS Solutions Architect Certification Training Course, Certified ScrumMaster (CSM) Certification Training, ITIL 4 Foundation Certification Training Course. We'll get a success message when the installation is finished. Finally, youll need to render it inside of App.js if there is no user token. In brief the options are: storing in JavaScript memory, storing in sessionStorage, storing in localStorage, and storing in a cookie. Instead of the dashboard, we'll see the login page. Like most problems in React, there are multiple ways to solve it. Call setItem with a key of token and the converted object. You will need to log in again since there is no token yet in localStorage, but after you do, you will remain logged in when you open a new tab. When you set up your route with app.use, Express will handle all requests the same. But if you try to open the application in another tab, the user will be logged out. Convert to an arrow function and name the new function saveToken. Now, its up to us to add some styling which is completely optional. Last but not least, start the server on port using app.listen. To begin, use npm to install react router. The form controls are being adjusted to display the value of our two state variables email and password. If the user shares their computer, they will remain logged in to the application even though they close the browser. The primary trade-off is security. After creating some components, we'll need to import them and define routes in App.js. All rights reserved. The callback takes two arguments: a req argument that has the request data, and a res argument that holds the result. Youll also need to install cors. The file should be saved and closed. Without requiring a login, the next user would have immediate access to the application. We'll construct a local API to get a user token in this stage. Add in the PropType from the new prop and destructure the props object to pull out the setToken prop. Open Login.js: In the previous step, you passed a new prop called setToken to the Login component. In the next step, youll create a local API that will return a user token. It's popular among online and mobile app developers because of its quick and simple interactive UI features. Create and export a function called useToken. Cheers and keep up the great contributions! Create a new file src/containers/Login.js and add the following. If you open a new window, tab, or even just refresh the page, you will lose the token and the user will need to login again. You can also return the values as an array, but an object will give users a chance to destructure only the values they want if you reuse this in another component. Open useToken.js to convert to localStorage. !1 thanks a lot really helpful article! Youll implement different token storage options and learn the security implications of each approach. Sign up for Infrastructure as a Newsletter. Thats not a problem. Non-memory storage solutions provide the advantage of reducing the number of times a user must log in, resulting in a better user experience. In this case, we'll add the service to the component directly. It's a risk, but for some applications, the convenience may be worth the risk. Fill out and submit the form and you will receive a web token then redirect to the page for the dashboard. It is very detailed and thorough. React is a popular JavaScript framework for creating front-end applications, such as user interfaces that allow users to interact with programs. We'll use Node.js to create a mock API that returns a use. In this series, you will build out examples of React projects to gain an understanding of this framework, giving you the knowledge you need to pursue front-end web development or start out on your way to full stack development. Then import Dashboard and Preferences by adding the following highlighted code: Next, import BrowserRouter, Switch, and Route from react-router-dom: Add a surrounding

with a className of wrapper and an

tag to serve as a template for the application. We'll need to save the login credentials once they've successfully authenticated. By convention, custom Hooks start with the keyword use*. This tutorial will cover sessionStorage and localStorage, since these are more modern than using cookies. I still have to go through docs for some parts!! The autoFocus flag is set for our email field, which means that when our form loads, it will focus on this field. I change the response into an Object and I was getting this Error. But moving the custom Hook to a different file will show how Hooks work outside of a component. react-router-dom has move onto version 6! Because the server isn't required for the final build, install it as a devDependency. After successfully retrieving the token, we'll use that API from our login page and render the component. We gave the Login component a new prop named setToken in the previous step. After that, replace any references to sessionStorage with localStorage. Make a local state to save the Username and Password. This is happening because you are calling useState in your custom Hook, which will trigger a component re-render: You now have a custom Hook to store your token in sessionStorage. This work is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International License. Click below to sign up and get $100 of credit to try our products over 60 days! It allows users to navigate between views of different components in a React application, change the browser URL, and keep the UI in sync with the URL. LocalStorage, unlike sessionStorage, saves data long after the session has ended. is it supposed to only string? We'll also have to set up cors. The next user would have immediate access to the application without a login. This image is from Firefox, but youll find the same results in Chrome or other modern browsers. We'll make a mock API that returns a user token, a login page that fetches the token, and a check for authentication that doesn't require rerouting the user. But there is still a problem. By the end of this tutorial, youll be able to add authentication to a React application and integrate the login and token storage strategies into a complete user workflow. This can lead to security vulnerabilities. First, import cors, then add it to the application by calling the use method on app: Next, listen to a specific route with app.use. Simplilearn also offers free online skill-up courses in several domains, from data science and business analytics to software development, AI, and machine learning. The problem is your code never alerts React that the token retrieval was successful. Working on improving health and education, reducing inequality, and spurring economic growth? A custom Hook usually wraps one or more built-in React Hooks along with custom implementations.