Build 10x products in minutes by chatting with AI - beyond just a prototype.
Topics
Syntax highlighting is a feature that displays source code or markup in different colors and fonts according to the category of terms. This feature facilitates developers to understand code structure, identify syntax errors, and improve readability. Modern web standards have made syntax highlighting a common practice in code editors and IDEs, enhancing the overall coding experience.
Prism.js is a lightweight, extensible syntax highlighter built with modern web standards in mind. It's designed to make code in a web page prettier without sacrificing performance. Prism supports a wide range of programming languages and comes with various themes that can be easily customized.
React Prism is the integration of Prism.js within a React application. It allows developers to leverage Prism's syntax highlighting features in their React projects. Using React Prism, developers can create interactive and visually appealing code blocks that enhance the learning and development experience.
Before you can start using React Prism, you need to set up your development environment. This typically involves creating a React application and ensuring that your app's build system supports the necessary transformations for Prism.js.
1// Initialize a new React project 2npx create-react-app my-prism-app 3cd my-prism-app 4
You can use npm or yarn to install Prism.js in your React project. This will add Prism.js to your project's dependencies and allow you to import Prism into your components.
1// Using npm 2npm install prismjs 3 4// Or using yarn 5yarn add prismjs 6
Once Prism.js is installed, you can import it into your React component. You can also import specific languages and themes as needed.
1// Importing Prism.js 2import Prism from 'prismjs'; 3 4// Importing a language 5import 'prismjs/components/prism-javascript'; 6 7// Importing a theme 8import 'prismjs/themes/prism-tomorrow.css'; 9
The Prism React Renderer is a custom component that uses Prism.js to render code blocks within a React application. It provides a render props based API that allows you to customize how the code block is rendered.
1import React from 'react'; 2import { Prism as SyntaxHighlighter } from 'react-syntax-highlighter'; 3 4const CodeBlock = ({ codeString, language }) => ( 5 <SyntaxHighlighter language={language}> 6 {codeString} 7 </SyntaxHighlighter> 8); 9
This component will take a string of code and the language it's written in, and render it with syntax highlighting.
To create a basic code block component with Prism.js, you must define a React component that wraps the highlighted code. You can use Prism to highlight the code and then set the inner HTML of a pre or code element.
1import React, { useEffect } from 'react'; 2import Prism from 'prismjs'; 3 4const CodeBlock = ({ code, language }) => { 5 useEffect(() => { 6 Prism.highlightAll(); 7 }, [code, language]); 8 9 return ( 10 <pre> 11 <code className={`language-${language}`}> 12 {code} 13 </code> 14 </pre> 15 ); 16}; 17 18export default CodeBlock; 19
This component uses the useEffect hook to call Prism.highlightAll() whenever the code or language props change, ensuring the syntax highlighting is applied to the latest code snippet.
Prism.js has a default set of themes that your project can easily include. However, you can customize these themes or create your own to match the style of your application. To do this, you can modify the CSS file directly or create a new css file with your desired styles.
1// Importing the default Prism.js theme 2import 'prismjs/themes/prism.css'; 3 4// Alternatively, you can create a custom CSS file and import it 5import './my-custom-prism-theme.css'; 6
Creating a custom CSS file gives you full control over your code blocks' colors, fonts, and other styles.
To theme the Prism React Renderer, you can pass a theme prop to the component. This theme prop is an object that defines the styles for tokens, languages, and other elements that Prism renders completely.
1import { Prism as SyntaxHighlighter } from 'react-syntax-highlighter'; 2import { dark } from 'react-syntax-highlighter/dist/esm/styles/prism'; 3 4const CodeBlock = ({ codeString, language }) => ( 5 <SyntaxHighlighter language={language} style={dark}> 6 {codeString} 7 </SyntaxHighlighter> 8); 9
In this example, the dark theme is imported and passed to the style prop, applying the dark theme to the rendered code block.
Prism.js supports many languages out of the box, but not all languages. If you need to highlight a language that Prism doesn't support by default, you can extend Prism with custom language definitions.
1import Prism from 'prismjs'; 2 3// Define a new language grammar 4Prism.languages.myCustomLang = { 5 'comment': /\/\*[\s\S]*?\*\/|\/\/.*/, 6 // Add more token definitions here 7}; 8 9// Now you can use `myCustomLang` as a language for highlighting 10
This code snippet defines a simple grammar for a custom language with single-line and multi-line comments.
To improve the performance of Prism.js in your React application, you can use the babel-plugin-prismjs plugin. This plugin allows you to include only the languages and themes you need, reducing the bundle size.
1// .babelrc configuration 2{ 3 "plugins": [ 4 ["prismjs", { 5 "languages": ["javascript", "css", "markup"], 6 "plugins": ["line-numbers"], 7 "theme": "twilight", 8 "css": true 9 }] 10 ] 11} 12
By configuring .babelrc with the babel-plugin-prismjs, you can specify which languages, plugins, and themes to include in your build.
You can create a lean highlighter component using Prism.js for a more lightweight implementation. This component will focus on the essentials, providing just the syntax highlighting without additional features.
1import React, { useEffect } from 'react'; 2import Prism from 'prismjs'; 3 4const LeanHighlighter = ({ code, language }) => { 5 useEffect(() => { 6 Prism.highlightAll(); 7 }, [code, language]); 8 9 return ( 10 <pre> 11 <code className={`language-${language}`}> 12 {code} 13 </code> 14 </pre> 15 ); 16}; 17 18export default LeanHighlighter; 19
This component is similar to the basic code block component but stripped down to provide only the necessary functionality for highlighting code.
The Prism React Renderer offers a powerful pattern called render props, allowing you to customize your code blocks' rendering. This pattern gives you access to the internal state and logic of the Prism React Renderer without exposing its internal structure.
1import { PrismAsyncLight as SyntaxHighlighter } from 'react-syntax-highlighter'; 2 3const CodeBlock = ({ codeString, language }) => ( 4 <SyntaxHighlighter 5 language={language} 6 children={({ tokens, getLineProps, getTokenProps }) => ( 7 <pre> 8 {tokens.map((line, i) => ( 9 <div key={i} {...getLineProps({ line, key: i })}> 10 {line.map((token, key) => ( 11 <span key={key} {...getTokenProps({ token, key })} /> 12 ))} 13 </div> 14 ))} 15 </pre> 16 )} 17 /> 18); 19
In this example, the children function receives the tokens, getLineProps, and getTokenProps as arguments, which can be used to render the code block with custom components or styles.
Prism supports various languages, but sometimes, you may need to limit which languages are included in your bundle. You can manage language support by selectively importing the languages you need.
1// Importing Prism and the languages you need 2import Prism from 'prismjs'; 3import 'prismjs/components/prism-javascript'; 4import 'prismjs/components/prism-python'; 5
By importing only the required languages, you can keep your application's bundle size smaller and more manageable.
You can use a CSS file or style object when styling code blocks. Using a CSS file is straightforward and involves creating a separate stylesheet for your code block styles.
1/* my-code-block-styles.css */ 2pre[class*="language-"] { 3 /* Your styles here */ 4} 5
Alternatively, you can use a style object to define styles directly within your React component.
1const codeBlockStyles = { 2 // Define your styles as a style object 3}; 4 5const CodeBlock = ({ code, language }) => ( 6 <pre style={codeBlockStyles}> 7 <code className={`language-${language}`}> 8 {code} 9 </code> 10 </pre> 11); 12
Both methods allow you to apply custom styles to your code blocks, and you can choose the one that best fits your workflow.
To dynamically generate style props for Prism components, you can use a function that returns a style object based on certain conditions, such as the language or theme.
1const getStyleProps = (language) => { 2 // Return different styles based on the language 3 return language === 'javascript' ? { backgroundColor: '#f0f0f0' } : {}; 4}; 5 6const CodeBlock = ({ code, language }) => ( 7 <pre style={getStyleProps(language)}> 8 <code className={`language-${language}`}> 9 {code} 10 </code> 11 </pre> 12); 13
This approach allows you to tailor the appearance of code blocks depending on the language or other properties.
Prism's tokens are the building blocks of syntax highlighting. They represent the smallest unit of text that can be styled individually. Tokens are typically organized in a doubly nested array, where the outer array represents lines and the inner arrays represent tokens within those lines.
1const tokens = [ 2 // First line of tokens 3 [ 4 { types: ['keyword'], content: 'const' }, 5 { types: ['plain'], content: ' ' }, 6 // More tokens... 7 ], 8 // More lines... 9]; 10
You can typically iterate over these tokens to apply the appropriate styles and create the highlighted code block when rendering.
Prism provides plugins to handle line numbers and separate lines, which can help display code with a more editor-like appearance.
1import 'prismjs/plugins/line-numbers/prism-line-numbers.css'; 2 3const CodeBlock = ({ code, language }) => ( 4 <pre className="line-numbers"> 5 <code className={`language-${language}`}> 6 {code} 7 </code> 8 </pre> 9); 10
By adding the line-numbers class to your pre element and including the corresponding CSS, Prism will automatically add line numbers to your code block.
You can create your own custom component for Prism highlighting to have more control over the rendering process and to encapsulate the highlighting logic.
1import React, { useEffect } from 'react'; 2import Prism from 'prismjs'; 3 4const CustomCodeBlock = ({ code, language }) => { 5 useEffect(() => { 6 Prism.highlightAll(); 7 }, [code, language]); 8 9 return ( 10 <pre className={`language-${language}`}> 11 <code> 12 {code} 13 </code> 14 </pre> 15 ); 16}; 17 18export default CustomCodeBlock; 19
This custom component uses the useEffect hook to trigger Prism's highlighting whenever the code or language changes. It encapsulates the highlighting logic, making it reusable across your application.
Prism can also be used with React Native to highlight syntax in mobile applications. While the setup may differ slightly due to the mobile environment, the core concepts remain the same.
1// Importing Prism into a React Native component 2import Prism from 'prismjs'; 3 4const CodeBlock = ({ code, language }) => { 5 // Highlight code using Prism 6 const highlightedCode = Prism.highlight(code, Prism.languages[language], language); 7 8 return ( 9 <Text style={styles.codeBlock}> 10 {highlightedCode} 11 </Text> 12 ); 13}; 14 15// Define your styles for the code block 16const styles = StyleSheet.create({ 17 codeBlock: { 18 // Your styles here 19 }, 20}); 21
In this example, the highlight method manually highlights the code, which is rendered within a Text component styled to resemble a code block.
When working with Prism components, passing props efficiently is essential to avoid unnecessary re-renders and performance issues.
1const CodeBlock = React.memo(({ code, language }) => { 2 useEffect(() => { 3 Prism.highlightAll(); 4 }, [code, language]); 5 6 return ( 7 <pre className={`language-${language}`}> 8 <code> 9 {code} 10 </code> 11 </pre> 12 ); 13}); 14
Using React.memo can help to prevent re-renders if the code and language props haven't changed, improving the performance of your Prism components.
To override the default styles provided by Prism, you can define your styles and ensure they are correctly applied to your code blocks.
1// Custom styles for Prism code blocks 2const customStyles = { 3 // Your custom styles here 4}; 5 6const CodeBlock = ({ code, language }) => ( 7 <pre style={customStyles}> 8 <code className={`language-${language}`}> 9 {code} 10 </code> 11 </pre> 12); 13
By passing a style object with your custom styles to the pre element, you can ensure that your styles take precedence over the default Prism styles.
Prism offers a variety of themes that can be included in your project by importing the corresponding CSS files. You can explore different themes to find the one best fits your application's design.
1// Importing a Prism theme 2import 'prismjs/themes/prism-okaidia.css'; 3
By importing different Prism CSS file themes, you can quickly switch between themes and test various styles for your code blocks.
In conclusion, using Prism in React projects allows developers to implement syntax highlighting easily. Best practices include:
By following these guidelines, developers can enhance the readability and aesthetics of code blocks in their React applications, providing a better experience for users and fellow developers.
Also, to speed up your React app development, try DhiWise React Builder , a smart UI builder that can help you get the app to market faster.
Happy coding!
