New Next.js Foundations Course for Beginners

Introduction

To effectively use Next.js, it helps to be familiar with JavaScript, React, and related web development concepts. But JavaScript and React are vast topics. How do you know when you’re ready to learn Next.js?

Welcome to the Next.js Foundations course! This beginner-friendly, example-led course will guide you through the prerequisite knowledge for Next.js. You will build a simple project step-by-step; starting with a JavaScript application, then migrating it to React and Next.js.

Each section builds on the previous one, so you can choose where to start depending on what you already know.


What is Next.js?

Next.js is a flexible React framework that gives you building blocks to create fast web applications.

But what exactly do we mean by this? Let’s spend some time expanding on what React and Next.js are and how they can help.

Building Blocks of a Web Application

There are a few things you need to consider when building modern applications. Such as:

  • User Interface - how users will consume and interact with your application.
  • Routing - how users navigate between different parts of your application.
  • Data Fetching - where your data lives and how to get it.
  • Rendering - when and where you render static or dynamic content.
  • Integrations - what third-party services you use (CMS, auth, payments, etc) and how you connect to them.
  • Infrastructure - where you deploy, store, and run your application code (Serverless, CDN, Edge, etc).
  • Performance - how to optimize your application for end-users.
  • Scalability - how your application adapts as your team, data, and traffic grow.
  • Developer Experience - your team’s experience building and maintaining your application.

For each part of your application, you will need to decide whether you will build a solution yourself or use other tools such as libraries and frameworks.

What is React?

React is a JavaScript library for building interactive user interfaces.

By user interfaces, we mean the elements that users see and interact with on-screen.

User Interface Example

By library, we mean React provides helpful functions to build UI, but leaves it up to the developer where to use those functions in their application.

Part of React’s success is that it is relatively unopinionated about the other aspects of building applications. This has resulted in a flourishing ecosystem of third-party tools and solutions.

It also means, however, that building a complete React application from the ground up requires some effort. Developers need to spend time configuring tools and reinventing solutions for common application requirements.

What is Next.js?

Next.js is a React framework that gives you building blocks to create web applications.

By framework, we mean Next.js handles the tooling and configuration needed for React, and provides additional structure, features, and optimizations for your application.

Next.js App Architecture

You can use React to build your UI, then incrementally adopt Next.js features to solve common application requirements such as routing, data fetching, integrations - all while improving the developer and end-user experience.

Whether you’re an individual developer or part of a larger team, you can leverage React and Next.js to build fully interactive, highly dynamic, and performant web applications.

In the next lessons, we will discuss how you can get started with React and Next.js.


From JavaScript to React

Rendering User Interfaces

To understand how React works, we first need a basic understanding of how browsers interpret your code to create interactive user interfaces (UI).

When a user visits a web page, the server returns an HTML file to the browser that may look like this:

HTML File and DOM

The browser then reads the HTML and constructs the Document Object Model (DOM).

What is the DOM?

The DOM is an object representation of the HTML elements. It acts as a bridge between your code and the user interface, and has a tree-like structure with parent and child relationships.

DOM and UI

You can use DOM methods and a programming language, such as JavaScript, to listen to user events and manipulate the DOM by selecting, adding, updating, and deleting specific elements in the user interface. DOM manipulation allows you to not only target specific elements, but also change their style and content.


Updating the UI with JavaScript and DOM Methods

Let’s see how you can use JavaScript and DOM methods by adding an h1 tag to your project.

Open your code editor and create a new index.html file. Inside the HTML file, add the following code:

<!-- index.html -->
<html>
  <body>
    <div></div>
  </body>
</html>

Then give the div a unique id so that you can target it later.

<!-- index.html -->
<html>
  <body>
    <div id="app"></div>
  </body>
</html>

To write JavaScript inside your HTML file, add a script tag:

<!-- index.html -->
<html>
  <body>
    <div id="app"></div>
    <script type="text/javascript"></script>
  </body>
</html>

Now, inside the script tag, you can use a DOM method, getElementById(), to select the <div> element by its id:

<!-- index.html -->
<html>
  <body>
    <div id="app"></div>

    <script type="text/javascript">
      const app = document.getElementById('app')
    </script>
  </body>
</html>

You can continue using DOM methods to create a new <h1> element:

<!-- index.html -->
<html>
  <body>
    <div id="app"></div>

    <script type="text/javascript">
      // Select the div element with 'app' id
      const app = document.getElementById('app')

      // Create a new H1 element
      const header = document.createElement('h1')

      // Create a new text node for the H1 element
      const headerContent = document.createTextNode(
        'Develop. Preview. Ship. 🚀'
      )

      // Append the text to the H1 element
      header.appendChild(headerContent)

      // Place the H1 element inside the div
      app.appendChild(header)
    </script>
  </body>
</html>

To make sure everything is working, open your HTML file inside your browser of choice. You should see an h1 tag that says, 'Develop. Preview. Ship. 🚀'.

HTML vs the DOM

If you look at the DOM elements inside your browser developer tools, you will notice the DOM includes the <h1> element. The DOM of the page is different from the source code - or in other words, the original HTML file you created.

Difference between DOM and Source Code (HTML)

This is because the HTML represents the initial page content, whereas the DOM represents the updated page content which was changed by the JavaScript code you wrote.

Updating the DOM with plain JavaScript is very powerful but verbose. You’ve written all this code to add an <h1> element with some text:

<!-- index.html -->
<script type="text/javascript">
  const app = document.getElementById('app')
  const header = document.createElement('h1')
  const headerContent = document.createTextNode('Develop. Preview. Ship. 🚀')
  header.appendChild(headerContent)
  app.appendChild(header)
</script>

As the size of an app or team grows, it can become increasingly challenging to build applications this way.

With this approach, developers spend a lot of time writing instructions to tell the computer how it should do things. But wouldn't it be nice to describe what you want to show and let the computer figure out how to update the DOM?

Imperative vs Declarative Programming

The code above is a good example of imperative programming. You’re writing the steps for how the user interface should be updated. But when it comes to building user interfaces, a declarative approach is often preferred because it can speed up the development process. Instead of having to write DOM methods, it would be helpful if developers were able to declare what they want to show (in this case, an h1 tag with some text).

In other words, imperative programming is like giving a chef step-by-step instructions on how to make a pizza. Declarative programming is like ordering a pizza without being concerned about the steps it takes to make the pizza. 🍕

A popular declarative library that helps developers build user interfaces is React.

React: A declarative UI library

As a developer, you can tell React what you want to happen to the user interface, and React will figure out the steps of how to update the DOM on your behalf.

In the next section, we'll explore how you can get started with React.


Getting Started with React

To use React in your project, you can load two React scripts from an external website called unpkg.com:

  • react is the core React library.
  • react-dom provides DOM-specific methods that enable you to use React with the DOM.
<!-- index.html -->
<html>
  <body>
    <div id="app"></div>

    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>

    <script type="text/javascript">
      const app = document.getElementById('app')
    </script>
  </body>
</html>

Instead of directly manipulating the DOM with plain JavaScript, you can use the ReactDOM.render() method from react-dom to tell React to render our <h1> title inside our #app element.

<!-- index.html -->
<html>
  <body>
    <div id="app"></div>

    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>

    <script type="text/javascript">
      const app = document.getElementById('app')
      ReactDOM.render(<h1>Develop. Preview. Ship. 🚀</h1>, app)
    </script>
  </body>
</html>

But if you try to run this code in the browser, you will get a syntax error:

React Syntax Error

This is because <h1>...</h1> is not valid Javascript. This piece of code is JSX.

What is JSX?

JSX is a syntax extension for JavaScript that allows you to describe your UI in a familiar HTML-like syntax. The nice thing about JSX is that apart from following three JSX rules, you don’t need to learn any new symbols or syntax outside of HTML and JavaScript.

Note that browsers don’t understand JSX out of the box, so you’ll need a JavaScript compiler, such as a Babel, to transform your JSX code into regular JavaScript.

Adding Babel to your project

To add Babel to your project, copy and paste the following script in your index.html file:

<script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>

In addition, you will need to inform Babel what code to transform by changing the script type to type=text/jsx.

<html>
  <body>
    <div id="app"></div>
    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
    <!-- Babel Script -->
    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
    <script type="text/jsx">
      const app = document.getElementById('app');
      ReactDOM.render(<h1>Develop. Preview. Ship. 🚀</h1>, app);
    </script>
  </body>
</html>

You can then run your code in the browser to confirm it is working correctly.

Comparing the declarative React code you just wrote:

<script type="text/jsx">
  const app = document.getElementById("app")
  ReactDOM.render(<h1>Develop. Preview. Ship. 🚀</h1>, app)
</script>

to the imperative JavaScript code you wrote in the previous section:

<script type="text/javascript">
  const app = document.getElementById('app')
  const header = document.createElement('h1')
  const headerContent = document.createTextNode('Develop. Preview. Ship. 🚀')
  header.appendChild(headerContent)
  app.appendChild(header)
</script>

You can start to see how by using React, you can cut down a lot of repetitive code.

And this is exactly what React does, it’s a library that contains reusable snippets of code that perform tasks on your behalf - in this case, updating the UI.


Essential JavaScript for React

While you can learn JavaScript and React at the same time, being familiar with JavaScript can make the process of learning React easier.

In the next sections, you will be introduced to some core concepts of React from a JavaScript perspective. Here’s a summary of the JavaScript topics that will be mentioned:

While this course does not dive into JavaScript, it’s good practice to stay up to date with the latest versions of JavaScript. But if you don’t feel proficient in JavaScript yet, don’t let this hinder you from starting to build with React!


React Core Concepts

There are three core concepts of React that you'll need to be familiar with to start building React applications. These are:

  • Components
  • Props
  • State

In the next sections, we will go through the concepts above and provide resources where you can continue learning them.


Building UI with Components

User interfaces can be broken down into smaller building blocks called components.

Components allow you to build self-contained, reusable snippets of code. If you think of components as LEGO bricks, you can take these individual bricks and combine them together to form larger structures. If you need to update a piece of the UI, you can update the specific component or brick.

Media Component Example

This modularity allows your code to be more maintainable as it grows because you can easily add, update, and delete components without touching the rest of our application.

The nice thing about React components is that they are just JavaScript. Let's see how you can write a React component, from a JavaScript perspective:

Creating components

In React, components are functions. Inside your script tag, write a function called header:

<script type="text/jsx">
  const app = document.getElementById("app")


  function header() {
  }

  ReactDOM.render(<h1>Develop. Preview. Ship. 🚀</h1>, app)
</script>

A component is a function that returns UI elements. Inside the return statement of the function, you can write JSX:

<script type="text/jsx">
  const app = document.getElementById("app")

  function header() {
     return (<h1>Develop. Preview. Ship. 🚀</h1>)
   }

  ReactDOM.render(, app)
</script>

To render this component to the DOM, you can pass it as the first argument in the ReactDOM.render() method:

<script type="text/jsx">

  const app = document.getElementById("app")

  function header() {
     return (<h1>Develop. Preview. Ship. 🚀</h1>)
   }


   ReactDOM.render(header, app)
</script>

But, wait a second. If you try to run the code above in your browser, you’ll get an error. To get this to work, there are two things you have to do:

First, React components should be capitalized to distinguish them from plain HTML and JavaScript.

function Header() {
  return <h1>Develop. Preview. Ship. 🚀</h1>
}

// Capitalize the React Component
ReactDOM.render(Header, app)

Second, you use React components the same way you’d use regular HTML tags, with angle brackets <>.

function Header() {
  return <h1>Develop. Preview. Ship. 🚀</h1>
}

ReactDOM.render(<Header />, app)

Nesting Components

Applications usually include more content than a single component. You can nest React components inside each other like you would regular HTML elements.

In your example, create a new component called HomePage:

function Header() {
  return <h1>Develop. Preview. Ship. 🚀</h1>
}
function HomePage() {
  return <div></div>
}

ReactDOM.render(<Header />, app)

Then nest the <Header> component inside the new <HomePage>component:

function Header() {
  return <h1>Develop. Preview. Ship. 🚀</h1>
}

function HomePage() {
  return (
    <div>
      {/* Nesting the Header component */}
      <Header />
    </div>
  )
}

ReactDOM.render(<Header />, app)

Component Trees

You can keep nesting React components this way to form component trees.

Component Tree

For example, your top-level HomePage component could hold a Header, an Article, and a Footer Component. And each of those components could in turn have their own child components and so on. For example, the Header component could contain a Logo, Title and Navigation component.

This modular format allows you to reuse components in different places inside your app.

In your project, since <HomePage> is now your top-level component, you can pass it to the ReactDOM.render() method:

function Header() {
  return <h1>Develop. Preview. Ship. 🚀</h1>
}

function HomePage() {
  return (
    <div>
      <Header />
    </div>
  )
}

ReactDOM.render(<HomePage />, app)

In the next section, we will discuss props and how you can use them to pass data between your components.


Displaying Data with Props

So far, if you were to reuse your <Header /> component, it would display the same content both times.

function Header() {
  return <h1>Develop. Preview. Ship. 🚀</h1>
}

function HomePage() {
  return (
    <div>
      <Header />
      <Header />
    </div>
  )
}

But what if you want to pass different text or you don't know the information ahead of time because you’re fetching data from an external source?

Regular HTML elements have attributes that you can use to pass pieces of information that change the behavior of those elements. For example, changing the src attribute of an <img> element changes the image that is shown. Changing the href attribute of an <a> tag changes the destination of the link.

In the same way, you can pass pieces of information as properties to React components. These are called props.

Props

Similar to a JavaScript function, you can design components that accept custom arguments (or props) that change the component’s behavior or what is visibly shown when it’s rendered to the screen. Then, you can pass down these props from parent components to child components.

Note: In React, data flows down the component tree. This is referred to as one-way data flow. State, which will be discussed in the next section, can be passed from parent to child components as props.

Using props

In your HomePage component, you can pass a custom title prop to the Header component, just like you’d pass HTML attributes:

// function Header() {
//   return <h1>Develop. Preview. Ship. 🚀</h1>
// }

function HomePage() {
  return (
    <div>
      <Header title="React 💙" />
    </div>
  )
}

// ReactDOM.render(<HomePage />, app)

And Header, the child component, can accept those props as its first function parameter:

function Header(props) {
//   return <h1>Develop. Preview. Ship. 🚀</h1>
// }

// function HomePage() {
//   return (
//     <div>
//       <Header title="React 💙" />
//     </div>
//   )
// }

// ReactDOM.render(<HomePage />, app)

If you console.log() props, you can see that it's an object with a title property.

function Header(props) {
    console.log(props) // { title: "React 💙" }
//   return <h1>React 💙</h1>
// }

// function HomePage() {
//   return (
//     <div>
//       <Header title="React 💙" />
//     </div>
//   )
// }

// ReactDOM.render(<HomePage />, app)

Since props is an object, you can use object destructuring to explicitly name the values of props inside your function parameters:

function Header({ title }) {
    console.log(title) // "React 💙"
//  return <h1>React 💙</h1>
// }

// function HomePage() {
//   return (
//     <div>
//       <Header title="React 💙" />
//     </div>
//   )
// }

// ReactDOM.render(<HomePage />, app)

Then you can replace the content of the <h1> tag with your title variable.

function Header({ title }) {
  console.log(title)
  return <h1>title</h1>
}

If you open your project in the browser, you will see that it is displaying the actual word “title”. This is because React thinks you’re intending to render a plain text string to the DOM.

You need a way to denote to React that this is a JavaScript variable.

Using Variables in JSX

To use the variable you defined, you can use curly braces {}, a special JSX syntax that allows you to write regular JavaScript directly inside your JSX markup.

// function Header({title}) {
//  console.log(title)
return <h1>{title}</h1>
// }

You can think of curly braces as a way to enter "JavaScript land" while you are in "JSX land". You can add any JavaScript expression (something that evaluates to a single value) inside curly braces. For example:

As we just discussed, an object property with dot notation:

function Header(props) {
  return <h1>{props.title}</h1>
}

A template literal:

function Header({ title }) {
  return <h1>{`Cool ${title}`}</h1>
}

The returned value of a function:

function createTitle(title) {
  if (title) {
    return title
  } else {
    return 'Default title'
  }
}

function Header({ title }) {
  return <h1>{createTitle(title)}</h1>
}

And ternary operators:

function Header({ title }) {
  return <h1>{title ? title : 'Default Title'}</h1>
}

You can now pass any string to your title prop, and since you’ve accounted for the default case in your component with the ternary operator, you could even not pass a title prop at all:

function Header({ title }) {
  return <h1>{title ? title : 'Default title'}</h1>
}

function Page() {
  return (
    <div>
      <Header />
    </div>
  )
}

Your component now accepts a generic title prop which you can reuse in different parts of your application. All you need to do is change the title:

function Page() {
  return (
    <div>
      <Header title="React 💙" />
      <Header title="A new title" />
    </div>
  )
}

Iterating through lists

It’s common to have data that you need to show as a list. You can use array methods to manipulate your data and generate UI elements that are identical in style but hold different pieces of information.

Note: React is unopinionated when it comes to data fetching, meaning you can choose whichever solution best suits your needs. Later on, we’ll discuss data fetching options in Next.js. But for now, you can use a simple array to represent data.

Add an array of names to your HomePage component:

function HomePage() {
  const names = ['Ada Lovelace', 'Grace Hopper', 'Margaret Hamilton']

  return (
    <div>
      <Header title="Develop. Preview. Ship. 🚀" />
    </div>
  )
}

You can then use the array.map() method to iterate over the array and use an arrow function to map a name to a list item:

function HomePage() {
  const names = ['Ada Lovelace', 'Grace Hopper', 'Margaret Hamilton']

  return (
    <div>
      <Header title="Develop. Preview. Ship. 🚀" />
      <ul>
        {names.map(name => (
          <li>{name}</li>
        ))}
      </ul>
    </div>
  )
}

Notice how you’ve used curly braces to weave in and out of "JavaScript" and "JSX" land.

If you run this code, React will give us a warning about a missing key prop. This is because React needs something to uniquely identify items in an array so it knows which elements to update in the DOM.

You can use the names for now since they are currently unique, but it's recommended to use something guaranteed to be unique, like an item ID.

function HomePage() {
  const names = ['Ada Lovelace', 'Grace Hopper', 'Margaret Hamilton']

  return (
    <div>
      <Header title="Develop. Preview. Ship. 🚀" />
      <ul>
        {names.map(name => (
          <li key={name}>{name}</li>
        ))}
      </ul>
    </div>
  )
}

In the next section, you will learn more about state and how to listen to user events in React.


Adding Interactivity with State

Let's explore how React helps us add interactivity with state and event handlers.

As an example, let’s create a like button in your project. First, add a button element to your code:

function HomePage() {
  const names = ['Ada Lovelace', 'Grace Hopper', 'Margaret Hamilton']

  return (
    <div>
      <Header title="Develop. Preview. Ship. 🚀" />
      <ul>
        {names.map(name => (
          <li key={name}>{name}</li>
        ))}
      </ul>

      <button>Like</button>
    </div>
  )
}

Listening to Events

To make the button do something when clicked, you can make use of the onClick event.

function HomePage() {
  // ...
  return (
    <div>
      {/* ... */}
      <button onClick={}>Like</button>
    </div>
  );
}

In React, event names are camelCased. The onClick event is one of many possible events you can use to respond to user interaction. For example, you can use onChange for input fields or onSubmit for forms.

Handling Events

You can define a function to "handle" events whenever they are triggered. Create a function before the return statement called handleClick():

function HomePage() {
  // ...

  function handleClick() {
    console.log("increment like count")
  }}

  return (
    <div>
      {/* ... */}
      <button onClick={}>Like</button>
    </div>
     )
   }

Then, you can call the handleClick function when the onClick event is triggered:

function HomePage() {
  //    ...
  function handleClick() {
    console.log('increment like count')
  }

  return (
    <div>
      {/* ... */}
      <button onClick={handleClick}>Like</button>
    </div>
  )
}

State and Hooks

React has a set of functions called hooks. Hooks allow you to add additional logic such as state to your components. You can think of state as any information in your UI that changes over time, usually triggered by user interaction.

Examples of state

You can use state to store and increment the number of times a user has clicked the like button. In fact, this is what the React hook to manage state is called: useState()

function HomePage() {
  React.useState()
}

useState() returns an array, and you can access and use those array values inside your component using array destructuring:

function HomePage() {
  const [] = React.useState()

  // ...
}

The first item in the array is the state value, which you can name anything. It’s recommended to name it something descriptive:

function HomePage() {
  const [likes] = React.useState()

  // ...
}

The second item in the array is a function to update the value. You can name the update function anything, but it's common to prefix it with set followed by the name of the state variable you’re updating:

function HomePage() {
  const [likes, setLikes] = React.useState()

  // ...
}

You can also take the opportunity to add the initial value of your likes state: zero.

function HomePage() {
  const [likes, setLikes] = React.useState(0)
}

Then, you can check the initial state is working by using the state variable inside your component.

function HomePage() {
  // ...
  const [likes, setLikes] = React.useState(0)

  return (
    // ...
    <button onClick={handleClick}>Like({likes});</button>
  )
}

Finally, you can call your state updater function, setLikes, inside the handleClick() function you previously defined:

function HomePage() {
  // ...
  const [likes, setLikes] = useState()

  function handleClick() {
    setLikes(likes + 1)
  }}

  return (
    <div>
      {/* ... */}
      <button onClick={handleClick}>Likes ({likes})</button>
    </div>
  )
}

Clicking the button will now call the handleClick function, which calls the setLikes state updater function with a single argument of the current number of likes + 1.

Note: Unlike props which are passed to components as the first function parameter, the state is initiated and stored within a component. You can pass the state information to children components as props, but the logic for updating the state should be kept within the component where state was initially created.

Managing State

This was only an introduction to state, and there’s more you can learn about managing state and data flow in your React applications. To learn more, we recommend you go through the Adding Interactivity and Managing State sections in the React Documentation.


How to continue learning React

You were just introduced to three essential React concepts: components, props, and state. Having a strong foundation in these will help you get started building React applications. Once you feel more confident, also check out these other React topics:

React Resources

Over the years, many courses, videos, and articles have been created to help developers learn React. While it’s hard to recommend resources that will fit your learning style, one invaluable reference is the React Documentation which contains interactive sandboxes to help you practice the topics.

When it comes to learning React, the best way to learn is to build. You can gradually adopt React by using <script> and what you've learned so far to add small components to an existing website. However, many developers have found the user and developer experience React enables valuable enough to dive right in and write their whole frontend project in React.

From React to Next.js

While React excels at building UI, it does take some work to independently build that UI into a fully functioning scalable application. The good news is that Next.js handles much of the setup and configuration and has additional features to help you build React applications.

Next, we'll migrate the example from React to Next.js, discuss how Next.js works, and introduce some web development concepts to help you learn more advanced Next.js features.


From React to Next.js

In the last lesson, we discussed how you can get started with React. This is what the final code looked like. If you’re starting from here, paste this code into an index.html file in your code editor.

<html>
  <body>
    <div id="app"></div>

    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>

    <script type="text/jsx">
      const app = document.getElementById("app")

      function Header({ title }) {
        return <h1>{title ? title : "Default title"}</h1>
      }

      function HomePage() {
        const names = ["Ada Lovelace", "Grace Hopper", "Margaret Hamilton"]

        const [likes, setLikes] = React.useState(0)

        function handleClick() {
          setLikes(likes + 1)
        }

        return (
          <div>
            <Header title="Develop. Preview. Ship. 🚀" />
            <ul>
              {names.map((name) => (
                <li key={name}>{name}</li>
              ))}
            </ul>

            <button onClick={handleClick}>Like ({likes})</button>
          </div>
        )
      }

      ReactDOM.render(<HomePage />, app)
    </script>
  </body>
</html>

Now, let’s see how you can move from a simple React app to Next.js.


Getting Started with Next.js

To add Next.js to your project, you will not need to load the react and react-dom scripts from unpkg.com anymore. Instead, you can install these packages locally using the Node Package Manager: npm.

Note: You will need to have Node.js installed on your machine (minimum version requirement), you can download it here.

To do so, create a new file called package.json with an empty object {}.

// package.json
{
}

In your terminal, run npm install react react-dom next. Once the installation is complete, you should be able to see your project dependencies listed inside your package.json file:

// package.json
{
  "dependencies": {
    "next": "^12.1.0",
    "react": "^17.0.2",
    "react-dom": "^17.0.2"
  }
}

You will also notice a new folder called node_modules that contains the actual files of our dependencies.

Jumping back to the index.html file, you can delete the following code:

  1. The react and react-dom scripts since you’ve installed them with NPM.
  2. The <html> and <body> tags because Next.js will create these for you.
  3. The code that interacts with app element and ReactDom.render() method.
  4. The Babel script because Next.js has a compiler that transforms JSX into valid JavaScript browsers can understand.
  5. The <script type="text/jsx"> tag.
  6. The React. part of the React.useState(0) function

After deleting the lines above, add import { useState } from "react" to the top of your file. Your code should look like this:

// index.html
import { useState } from 'react'
function Header({ title }) {
  return <h1>{title ? title : 'Default title'}</h1>
}

function HomePage() {
  const names = ['Ada Lovelace', 'Grace Hopper', 'Margaret Hamilton']

  const [likes, setLikes] = useState(0)

  function handleClick() {
    setLikes(likes + 1)
  }

  return (
    <div>
      <Header title="Develop. Preview. Ship. 🚀" />
      <ul>
        {names.map(name => (
          <li key={name}>{name}</li>
        ))}
      </ul>

      <button onClick={handleClick}>Like ({likes})</button>
    </div>
  )
}

The only code left in the HTML file is JSX, so you can change the file type from .html to .js or .jsx.

Now, there are three more things you need to do to fully transition to a Next.js app:

  1. Move the index.js file to a new folder called pages (more on this later).
  2. Add default export to your main React component to help Next.js distinguish which component to render as the main component of this page.
   // ...
   export default function HomePage() {
   //  ...
  1. Add a script to your package.json file to run the Next.js development server while you develop.
   // package.json
   {
    "scripts": {
        "dev": "next dev"
    },
     // "dependencies": {
     //   "next": "^11.1.0",
     //   "react": "^17.0.2",
     //   "react-dom": "^17.0.2"
     // }
   }

Running the development server

To confirm everything works, you can view your app by running npm run dev inside your terminal and navigating to localhost:3000 in the browser. Then, make a small change to the code and save it.

Once you save the file, you should notice the browser automatically updates to reflect the change.

This feature is called Fast Refresh. It gives you instantaneous feedback on any edits you make and comes pre-configured with Next.js.

To recap, your code went from this...

<html>
  <body>
    <div id="app"></div>

    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>

    <script type="text/jsx">
      const app = document.getElementById("app")

      function Header({ title }) {
        return <h1>{title ? title : "Default title"}</h1>
      }

      function HomePage() {
        const names = ["Ada Lovelace", "Grace Hopper", "Margaret Hamilton"]
        const [likes, setLikes] = React.useState(0)

        function handleClick() {
          setLikes(likes + 1)
        }

        return (
          <div>
            <Header title="Develop. Preview. Ship. 🚀" />
            <ul>
              {name.map((name) => (
                <li key={name}>{name}</li>
              ))}
            </ul>

            <button onClick={handleClick}>Like ({likes})</button>
          </div>
        )
      }

      ReactDOM.render(<HomePage />, app)
    </script>
  </body>
</html>

...to this:

import { useState } from 'react'

function Header({ title }) {
  return <h1>{title ? title : 'Default title'}</h1>
}

export default function HomePage() {
  const names = ['Ada Lovelace', 'Grace Hopper', 'Margaret Hamilton']
  const [likes, setLikes] = useState(0)

  function handleClick() {
    setLikes(likes + 1)
  }

  return (
    <div>
      <Header title="Develop. Preview. Ship. 🚀" />
      <ul>
        {names.map(name => (
          <li key={name}>{name}</li>
        ))}
      </ul>

      <button onClick={handleClick}>Like ({likes})</button>
    </div>
  )
}

On the surface, this is a small reduction in lines of code, but it does help highlight something: React is a library that provides essential primitives for building modern interactive UI. But there is still some work involved to combine that UI you create into an application.

Looking at the migration, you may already be getting a sense of the benefits of using Next.js. You removed the babel script, a taste of the complex tooling configuration you no longer have to think about. You also saw Fast Refresh in action, just one of the many developer experience features you can expect with Next.js.


Next Steps

Congratulations on creating your first Next.js application!

To summarize, you explored the foundational knowledge for React and Next.js, and you migrated from a simple React Application to a Next.js application.

Now you can choose the next step in your Next.js journey. You can:

  1. Learn how to use Next.js by creating your first app - this course will introduce you to the main Next.js features and get you practicing by building a more complex project.
  2. Dive deeper into how Next.js works by continuing this course.

In the next lesson, we’ll explore how Next.js works by introducing some related web development concepts. Being familiar with these concepts will help expand your foundation and make it easier to learn more advanced Next.js features.


How Next.js Works

Before you learn more advanced Next.js features, it would be helpful to understand the basics of how Next.js works.

At the beginning of this course, we talked about how React is relatively unopinionated about how you build and structure your applications - there are multiple ways to build applications with React. Next.js provides a framework to structure your application, and optimizations that help make both the development process and final application faster.

In the next sections, we’ll look at what happens to your application code during these different stages:

  • The environment where your code runs: Development vs. Production
  • When your code runs: Build Time vs. Runtime
  • Where rendering happens: Client vs. Server

Now let’s dive deeper into these concepts and discuss some of the processes Next.js is doing behind the scenes.


Development and Production Environments

You can think of environments as the context in which your code is running.

During development, you’re building and running the application on your local machine. Going to production is the process of making your application ready to be deployed and consumed by users.

How this applies to Next.js

Next.js provides features for both the development and production stages of an application. For example:

  • In the development stage, Next.js optimizes for the developer and their experience building the application. It comes with features that aim to improve the Developer Experience such the TypeScript and ESLint integrationFast Refresh, and more.
  • In the production stage, Next.js optimizes for the end-users, and their experience using the application. It aims to transform the code to make it performant and accessible.

Since each environment has different considerations and goals, there is a lot that needs to be done to move an application from development to production. For instance, the application code needs to be compiled, bundled, minified, and code split.

The Next.js Compiler

Next.js handles much of these code transformations and underlying infrastructure to make it easier for your application to go to production.

This is made possible because Next.js has a compiler written in Rust, a low-level programming language, and SWC, a platform that can be used for compilation, minification, bundling, and more.

In the next sections, we'll explore what each of these transformations are.


What is Compiling?

Developers write code in languages that are more developer-friendly such as JSX, TypeScript, and modern versions of JavaScript. While these languages improve the efficiency and confidence of developers, they need to be compiled into JavaScript before browsers can understand them.

Compiling refers to the process of taking code in one language and outputting it in another language or another version of that language.

Compiling

In Next.js, compilation happens during the development stage as you edit your code, and as part of the build step to prepare your application for production.


What is Minifying?

Developers write code that is optimized for human readability. This code might contain extra information that is not necessary for the code to run, such as comments, spaces, indents, and multiple lines.

Minification

Minification is the process of removing unnecessary code formatting and comments without changing the code’s functionality. The goal is to improve the application’s performance by decreasing file sizes.

In Next.js, JavaScript and CSS files are automatically minified for production.


What is Bundling?

Developers break up their application into modules, components, and functions that can be used to build larger pieces of their application. Exporting and importing these internal modules, as well as external third-party packages, creates a complex web of file dependencies.

Bundling

Bundling is the process of resolving the web of dependencies and merging (or ‘packaging’) the files (or modules) into optimized bundles for the browser, with the goal of reducing the number of requests for files when a user visits a web page.


What is Code Splitting?

Developers usually split their applications into multiple pages that can be accessed from different URLs. Each of these pages becomes a unique entry point into the application.

Code-splitting is the process of splitting the application’s bundle into smaller chunks required by each entry point. The goal is to improve the application's initial load time by only loading the code required to run that page.

Code Splitting

Next.js has built-in support for code splitting. Each file inside your pages/ directory will be automatically code split into its own JavaScript bundle during the build step.

Further:

  • Any code shared between pages is also split into another bundle to avoid re-downloading the same code on further navigation.
  • After the initial page load, Next.js can start pre-loading the code of other pages users are likely to navigate to.
  • Dynamic imports are another way to manually split what code is initially loaded.

Build Time and Runtime

Build time (or build step) is the name given to a series of steps that prepare your application code for production.

When you build your application, Next.js will transform your code into production-optimized files ready to be deployed to servers and consumed by users. These files include:

  • HTML files for statically generated pages
  • JavaScript code for rendering pages on the server
  • JavaScript code for making pages interactive on the client
  • CSS files

Runtime (or request time) refers to the period of time when your application runs in response to a user’s request, after your application has been built and deployed.

Next, let’s discuss some of the terms introduced in this section, such as client, server, and rendering.


Client and Server

In the context of web applications, the client refers to the browser on a user’s device that sends a request to a server for your application code. It then turns the response it receives from the server into an interface the user can interact with.

Client and Server

Server refers to the computer in a data centre that stores your application code, receives requests from a client, does some computation, and sends back an appropriate response.


What is Rendering?

There is an unavoidable unit of work to convert the code you write in React into the HTML representation of your UI. This process is called rendering.

Rendering can take place on the server or on the client. It can happen either ahead of time at build time, or on every request at runtime.

With Next.js, three types of rendering methods are available: Server-Side Rendering, Static Site Generation, and Client-Side Rendering.

Pre-Rendering

Server-Side Rendering and Static Site Generation are also referred to as Pre-Rendering because the fetching of external data and transformation of React components into HTML happens before the result is sent to the client.

Client-Side Rendering vs. Pre-Rendering

In a standard React application, the browser receives an empty HTML shell from the server along with the JavaScript instructions to construct the UI. This is called client-side rendering because the initial rendering work happens on the user's device.

Client-Side Rendering

Note: You can opt to use client-side rendering for specific components in your Next.js application by choosing to fetch data with React’s useEffect() or a data fetching hook such as useSWR.

In contrast, Next.js pre-renders every page by default. Pre-rendering means the HTML is generated in advance, on a server, instead of having it all done by JavaScript on the user's device.

In practice, this means that for a fully client-side rendered app, the user will see a blank page while the rendering work is being done. Compared to a pre-rendered app, where the user will see the constructed HTML:

Pre-Rendering

Let’s discuss the two types of pre-rendering:

Server-Side Rendering

With server-side rendering, the HTML of the page is generated on a server for each request. The generated HTML, JSON data, and JavaScript instructions to make the page interactive are then sent to the client.

On the client, the HTML is used to show a fast non-interactive page, while React uses the JSON data and JavaScript instructions to make components interactive (for example, attaching event handlers to a button). This process is called hydration.

In Next.js, you can opt to server-side render pages by using getServerSideProps.

Note: React 18 and Next 12 introduce an alpha version of React server components. Server components are completely rendered on the server and do not require client-side JavaScript to render. In addition, server components allow developers to keep some logic on the server and only send the result of that logic to the client. This reduces the bundle size sent to the client and improves client-side rendering performance. Learn more about React server components here.

Static Site Generation

With Static Site Generation, the HTML is generated on the server, but unlike server-side rendering, there is no server at runtime. Instead, content is generated once, at build time, when the application is deployed, and the HTML is stored in a CDN and re-used for each request.

In Next.js, you can opt to statically generate pages by using getStaticProps.

Note: You can use Incremental Static Regeneration to create or update static pages after you’ve built your site. This means you do not have to rebuild your entire site if your data changes.

The beauty of Next.js is that you can choose the most appropriate rendering method for your use case on a page-by-page basis, whether that's Static Site Generation, Server-side Rendering, or Client-Side Rendering. To learn more about which rendering method is right for your specific use case, see the data fetching docs.

In the next section, we’ll discuss where your code can be stored or run after it’s deployed.


What is the Network?

It’s helpful to know where your application code is stored and run once it’s deployed to the network. You can think of the network as linked computers (or servers) capable of sharing resources. In the case of a Next.js application, your application code can be distributed to origin servers, Content Delivery Networks (CDNs), and the Edge. Let’s see what each of these are:

Origin Servers

As we discussed earlier, the server refers to the main computer that stores and runs the original version of your application code.

We use the term origin to distinguish this server from the other places application code can be distributed to, such as CDN servers and Edge servers.

When an origin server receives a request, it does some computation before sending a response. The result of this computation work can be moved to a CDN (Content Delivery Network).

Content Delivery Network

CDNs store static content (such as HTML and image files) in multiple locations around the world and are placed between the client and the origin server. When a new request comes in, the closest CDN location to the user can respond with the cached result.

CDNs

This reduces the load on the origin because the computation doesn’t have to happen on each request. It also makes it faster for the user because the response comes from a location geographically closer to them.

In Next.js, since pre-rendering can be done ahead of time, CDNs are well suited to store the static result of the work - making content delivery faster.

The Edge

The Edge is a generalized concept for the fringe (or edge) of the network, closest to the user. CDNs could be considered part of "the Edge" because they store static content at the fringe (edge) of the network.

Similar to CDNs, Edge servers are distributed to multiple locations around the world. But unlike CDNs, which store static content, some Edge servers can run code.

This means both caching and code execution can be done at the Edge closer to the user.

By running code at the Edge, you can move some of the work that was traditionally done client-side or server-side to the Edge (see examples with Next.js here). This can make your application more performant because it reduces the amount of code sent to the client, and part of the user's request does not have to go all the way back to the origin server - thus reducing latency.

In Next.js, you can run code at the Edge with Middleware, and soon with React Server Components.


Next Steps

Congratulations on finishing the Next.js Foundations course!

To continue learning Next.js, we recommend you create your first Next.js app with our tutorial which will introduce you to the main features.

You can also check out our documentation and explore our extensive list of examples.

Original article source at https://nextjs.org

#next #react #javascript #nextjs #reactjs #programming 

 

What is GEEK

Buddha Community

New Next.js Foundations Course for Beginners

NBB: Ad-hoc CLJS Scripting on Node.js

Nbb

Not babashka. Node.js babashka!?

Ad-hoc CLJS scripting on Node.js.

Status

Experimental. Please report issues here.

Goals and features

Nbb's main goal is to make it easy to get started with ad hoc CLJS scripting on Node.js.

Additional goals and features are:

  • Fast startup without relying on a custom version of Node.js.
  • Small artifact (current size is around 1.2MB).
  • First class macros.
  • Support building small TUI apps using Reagent.
  • Complement babashka with libraries from the Node.js ecosystem.

Requirements

Nbb requires Node.js v12 or newer.

How does this tool work?

CLJS code is evaluated through SCI, the same interpreter that powers babashka. Because SCI works with advanced compilation, the bundle size, especially when combined with other dependencies, is smaller than what you get with self-hosted CLJS. That makes startup faster. The trade-off is that execution is less performant and that only a subset of CLJS is available (e.g. no deftype, yet).

Usage

Install nbb from NPM:

$ npm install nbb -g

Omit -g for a local install.

Try out an expression:

$ nbb -e '(+ 1 2 3)'
6

And then install some other NPM libraries to use in the script. E.g.:

$ npm install csv-parse shelljs zx

Create a script which uses the NPM libraries:

(ns script
  (:require ["csv-parse/lib/sync$default" :as csv-parse]
            ["fs" :as fs]
            ["path" :as path]
            ["shelljs$default" :as sh]
            ["term-size$default" :as term-size]
            ["zx$default" :as zx]
            ["zx$fs" :as zxfs]
            [nbb.core :refer [*file*]]))

(prn (path/resolve "."))

(prn (term-size))

(println (count (str (fs/readFileSync *file*))))

(prn (sh/ls "."))

(prn (csv-parse "foo,bar"))

(prn (zxfs/existsSync *file*))

(zx/$ #js ["ls"])

Call the script:

$ nbb script.cljs
"/private/tmp/test-script"
#js {:columns 216, :rows 47}
510
#js ["node_modules" "package-lock.json" "package.json" "script.cljs"]
#js [#js ["foo" "bar"]]
true
$ ls
node_modules
package-lock.json
package.json
script.cljs

Macros

Nbb has first class support for macros: you can define them right inside your .cljs file, like you are used to from JVM Clojure. Consider the plet macro to make working with promises more palatable:

(defmacro plet
  [bindings & body]
  (let [binding-pairs (reverse (partition 2 bindings))
        body (cons 'do body)]
    (reduce (fn [body [sym expr]]
              (let [expr (list '.resolve 'js/Promise expr)]
                (list '.then expr (list 'clojure.core/fn (vector sym)
                                        body))))
            body
            binding-pairs)))

Using this macro we can look async code more like sync code. Consider this puppeteer example:

(-> (.launch puppeteer)
      (.then (fn [browser]
               (-> (.newPage browser)
                   (.then (fn [page]
                            (-> (.goto page "https://clojure.org")
                                (.then #(.screenshot page #js{:path "screenshot.png"}))
                                (.catch #(js/console.log %))
                                (.then #(.close browser)))))))))

Using plet this becomes:

(plet [browser (.launch puppeteer)
       page (.newPage browser)
       _ (.goto page "https://clojure.org")
       _ (-> (.screenshot page #js{:path "screenshot.png"})
             (.catch #(js/console.log %)))]
      (.close browser))

See the puppeteer example for the full code.

Since v0.0.36, nbb includes promesa which is a library to deal with promises. The above plet macro is similar to promesa.core/let.

Startup time

$ time nbb -e '(+ 1 2 3)'
6
nbb -e '(+ 1 2 3)'   0.17s  user 0.02s system 109% cpu 0.168 total

The baseline startup time for a script is about 170ms seconds on my laptop. When invoked via npx this adds another 300ms or so, so for faster startup, either use a globally installed nbb or use $(npm bin)/nbb script.cljs to bypass npx.

Dependencies

NPM dependencies

Nbb does not depend on any NPM dependencies. All NPM libraries loaded by a script are resolved relative to that script. When using the Reagent module, React is resolved in the same way as any other NPM library.

Classpath

To load .cljs files from local paths or dependencies, you can use the --classpath argument. The current dir is added to the classpath automatically. So if there is a file foo/bar.cljs relative to your current dir, then you can load it via (:require [foo.bar :as fb]). Note that nbb uses the same naming conventions for namespaces and directories as other Clojure tools: foo-bar in the namespace name becomes foo_bar in the directory name.

To load dependencies from the Clojure ecosystem, you can use the Clojure CLI or babashka to download them and produce a classpath:

$ classpath="$(clojure -A:nbb -Spath -Sdeps '{:aliases {:nbb {:replace-deps {com.github.seancorfield/honeysql {:git/tag "v2.0.0-rc5" :git/sha "01c3a55"}}}}}')"

and then feed it to the --classpath argument:

$ nbb --classpath "$classpath" -e "(require '[honey.sql :as sql]) (sql/format {:select :foo :from :bar :where [:= :baz 2]})"
["SELECT foo FROM bar WHERE baz = ?" 2]

Currently nbb only reads from directories, not jar files, so you are encouraged to use git libs. Support for .jar files will be added later.

Current file

The name of the file that is currently being executed is available via nbb.core/*file* or on the metadata of vars:

(ns foo
  (:require [nbb.core :refer [*file*]]))

(prn *file*) ;; "/private/tmp/foo.cljs"

(defn f [])
(prn (:file (meta #'f))) ;; "/private/tmp/foo.cljs"

Reagent

Nbb includes reagent.core which will be lazily loaded when required. You can use this together with ink to create a TUI application:

$ npm install ink

ink-demo.cljs:

(ns ink-demo
  (:require ["ink" :refer [render Text]]
            [reagent.core :as r]))

(defonce state (r/atom 0))

(doseq [n (range 1 11)]
  (js/setTimeout #(swap! state inc) (* n 500)))

(defn hello []
  [:> Text {:color "green"} "Hello, world! " @state])

(render (r/as-element [hello]))

Promesa

Working with callbacks and promises can become tedious. Since nbb v0.0.36 the promesa.core namespace is included with the let and do! macros. An example:

(ns prom
  (:require [promesa.core :as p]))

(defn sleep [ms]
  (js/Promise.
   (fn [resolve _]
     (js/setTimeout resolve ms))))

(defn do-stuff
  []
  (p/do!
   (println "Doing stuff which takes a while")
   (sleep 1000)
   1))

(p/let [a (do-stuff)
        b (inc a)
        c (do-stuff)
        d (+ b c)]
  (prn d))
$ nbb prom.cljs
Doing stuff which takes a while
Doing stuff which takes a while
3

Also see API docs.

Js-interop

Since nbb v0.0.75 applied-science/js-interop is available:

(ns example
  (:require [applied-science.js-interop :as j]))

(def o (j/lit {:a 1 :b 2 :c {:d 1}}))

(prn (j/select-keys o [:a :b])) ;; #js {:a 1, :b 2}
(prn (j/get-in o [:c :d])) ;; 1

Most of this library is supported in nbb, except the following:

  • destructuring using :syms
  • property access using .-x notation. In nbb, you must use keywords.

See the example of what is currently supported.

Examples

See the examples directory for small examples.

Also check out these projects built with nbb:

API

See API documentation.

Migrating to shadow-cljs

See this gist on how to convert an nbb script or project to shadow-cljs.

Build

Prequisites:

  • babashka >= 0.4.0
  • Clojure CLI >= 1.10.3.933
  • Node.js 16.5.0 (lower version may work, but this is the one I used to build)

To build:

  • Clone and cd into this repo
  • bb release

Run bb tasks for more project-related tasks.

Download Details:
Author: borkdude
Download Link: Download The Source Code
Official Website: https://github.com/borkdude/nbb 
License: EPL-1.0

#node #javascript

Eva  Murphy

Eva Murphy

1625674200

Google analytics Setup with Next JS, React JS using Router Events - 14

In this video, we are going to implement Google Analytics to our Next JS application. Tracking page views of an application is very important.

Google analytics will allow us to track analytics information.

Frontend: https://github.com/amitavroy/video-reviews
API: https://github.com/amitavdevzone/video-review-api
App link: https://video-reviews.vercel.app

You can find me on:
Twitter: https://twitter.com/amitavroy7​
Discord: https://discord.gg/Em4nuvQk

#next js #js #react js #react #next #google analytics

Lilyan  Streich

Lilyan Streich

1599119110

Next js Tutorial For Beginners

Next js Tutorial For Beginners is the today’s topic. It is no secret that creating single-page applications can be immensely challenging these days. But with the help of some libraries, frameworks, and tools, it is effortless nowadays. React.js is the common frontend libraries among the Front-end developers. Its virtual dom theory makes React faster and gives us the better application performance. Now, one problem is that Single Page Applications are not at all SEO  friendly because it is rendered on the Client side  and not Server side . So when the Search Engine crawlers try to send a request, they cannot get our meta content or description and not even the main content. Search Engines do not care about how your app is architected or whatever ideology was used to adjust and fetch the right material. Their bots are not as smart as using your apps as a real user would. All they care about is that once they send their spiders to crawl and index your site, whatever the server provides on the first request is what gets indexed. In our case, all they get is our div tag with an id and bundled JS file, and we can not index our website correctly. So some how, we need a SSR to tackle this problem and in React js, Next.js is the perfect solution.

#js #react.js #next.js

Eva  Murphy

Eva Murphy

1625751960

Laravel API and React Next JS frontend development - 28

In this video, I wanted to touch upon the functionality of adding Chapters inside a Course. The idea was to not think much and start the development and pick up things as they come.

There are places where I get stuck and trying to find answers to it up doing what every developer does - Google and get help. I hope this will help you understand the flow and also how developers debug while doing development.

App url: https://video-reviews.vercel.app
Github code links below:
Next JS App: https://github.com/amitavroy/video-reviews
Laravel API: https://github.com/amitavdevzone/video-review-api

You can find me on:
Twitter: https://twitter.com/amitavroy7​
Discord: https://discord.gg/Em4nuvQk

#next js #api #react next js #next #frontend #development

Ananya Gupta

Ananya Gupta

1608615386

Top Reasons To Choose ReactJS

The principal concept at the back of ReactJS improvement become to discover a framework that allows in constructing a dynamic library with excessive performance. An appropriate instance of this becomes to offer newsfeeds on equal time whilst human beings are chatting. Optimization of the improvement technique and bringing on JavaScript become all that become required at that time. ReactJS is greater like an open-supply JavaScript library in place of a framework. Used for constructing superb consumer interfaces, it is ideal for rendering performance.

Reasons to pick out React.js/React/ReactJS

Out of the several reasons React.JS can be future of hybrid mobile app, some of the interesting ones are:

  • React’s virtual DOM is faster as it only refreshes a part of the page, rather than the conventional full refresh model
  • Easy to create UI Test Cases
  • Easy to reuse the code components
  • It can display components in large amounts quickly and efficiently
  • Specialized chrome extension makes it easy to debug
  • Any data changes require manual processing
  • It is view oriented
  • It’s one of the top JavaScript frameworks among ReactJS developers and is growing
  • Rendering the code from the server to browser will eventually improve the SEO of the webpage
  • It improves debugging speed, making it easier for developers
  • It covers both iOS and Android
  • As it makes use of reusable components, it becomes easy for the hybrid applications to render natively
  • React Native UI components can be applied without re-writing to an existing app’s code
  • It provides support for both front-end and server-side

Cons of ReactJS Making use of JSX which permits blending HTML with JavaScript is taken into consideration a critical drawback through ReactJS builders as it’s far complicated and has a steep mastering curve. Join ReactJS Online Training and learn the regular launch of the latest tools, documentation nonetheless stays incomplete, which makes it tough for brand spanking new ReactJS builders to apprehend and code. With the excessive tempo of improvement, ReactJS builders have to quickly research new methods of improvement. With rapid evolution, now no longer each developer is capable of preserve tempo. What’s our tackle it?

AngularJS is a featured framework at the same time as ReactJS is a library. You will need to write much less code with ReactJS and it even plays higher because of the implementation of digital DOM. As React has simply commenced its network is developing. Node.js is a JavaScript runtime that is rapid and lightweight. It may be used to create rapid and scalable networking packages. With Client-Side statistics rendering and a top configuration, ReactJS is an outright desire of JavaScript framework Developers.

#react js online training #react js online course #online react js course #online react js training #react js training in noida #react js training in delhi