Leveraging Styled JSX in Next.js

1. Introduction

In this tutorial, we aim to explore the usage of Styled JSX in Next.js. Styled JSX is a CSS-in-JS library that allows you to write encapsulated and scoped CSS inside your JSX code. This results in better component encapsulation as each component's style is defined within the component itself.

By the end of this tutorial, you will learn how to:

• Write scoped CSS within your JSX code
• Use global styles with Styled JSX
• Dynamically change styles with props

Prerequisites: Basic knowledge of JavaScript, JSX, and CSS is required. Familiarity with Next.js would be beneficial but not necessary.

2. Step-by-Step Guide

To begin with, you need to understand that Styled JSX provides a unique approach to styling in React and Next.js. It allows you to write standard CSS in your components without worrying about class name collisions.

Here is a typical example of what a Styled JSX component looks like:

function ExampleComponent() {
  return (
    <div>
      <p>Hello, Next.js</p>
      <style jsx>{`
        p {
          color: blue;
        }
      `}</style>
    </div>
  )
}

In the above code, the style tag is used along with the JSX attribute to write CSS within a component. The CSS written will only apply to the component in which it is defined.

Best Practices and Tips

• Always encapsulate your styles within the component they're needed to avoid unnecessary global styles.
• Take advantage of dynamic styles with props to create reusable and customizable components.

3. Code Examples

Example 1: Basic Styled JSX

function BasicStyledComponent() {
  return (
    <div>
      <p>Hello, Next.js</p>
      <style jsx>{`
        p {
          color: blue;
        }
      `}</style>
    </div>
  )
}

In this example, the <p> tag within the BasicStyledComponent will be styled with blue text. No other <p> tags in other components will be affected.

Example 2: Global Styles

function GlobalStyleComponent() {
  return (
    <div>
      <p>Hello, Next.js</p>
      <style jsx global>{`
        p {
          color: blue;
        }
      `}</style>
    </div>
  )
}

In this example, the global keyword is used. This means that all <p> tags in the entire application will have blue text.

4. Summary

Throughout this tutorial, we've learned how to use Styled JSX to write encapsulated and scoped CSS in our JSX code. We've also looked at how to apply global styles and dynamically change styles with props.

For further learning, it would be beneficial to look into more complex uses of Styled JSX, such as theming and CSS animations.

5. Practice Exercises

1. Create a component with a <h1> tag and use Styled JSX to change its color.
2. Create a component with a <button> tag and use Styled JSX to add hover effects.
3. Create a component that takes in a prop named 'color'. Use this prop to dynamically change the color of a <p> tag.

Solutions

1. Solution to Exercise 1:

function HeadingComponent() {
  return (
    <div>
      <h1>Hello, Next.js</h1>
      <style jsx>{`
        h1 {
          color: blue;
        }
      `}</style>
    </div>
  )
}

1. Solution to Exercise 2:

function ButtonComponent() {
  return (
    <div>
      <button>Click me</button>
      <style jsx>{`
        button {
          background: blue;
          color: white;
        }
        button:hover {
          background: white;
          color: blue;
        }
      `}</style>
    </div>
  )
}

1. Solution to Exercise 3:

function ColorfulText({color}) {
  return (
    <div>
      <p>Hello, Next.js</p>
      <style jsx>{`
        p {
          color: ${color};
        }
      `}</style>
    </div>
  )
}

In this exercise, the 'color' prop is used to dynamically set the color of the <p> tag. If you use the ColorfulText component with a 'color' prop of 'red', the text will be red.