跳到主要内容

代码块

Code blocks within documentation are super-powered 💪.

代码的标题

You can add a title to the code block by adding a title key after the language (leave a space between them).

```jsx title="/src/components/HelloCodeTitle.js"
function HelloCodeTitle(props) {
return <h1>Hello, {props.name}</h1>;
}
```
http://localhost:3000
/src/components/HelloCodeTitle.js
function HelloCodeTitle(props) {
return <h1>Hello, {props.name}</h1>;
}

Syntax highlighting

Code blocks are text blocks wrapped around by strings of 3 backticks. You may check out this reference for the specifications of MDX.

```js
console.log('Every repo must come with a mascot.');
```

Use the matching language meta string for your code block, and Docusaurus will pick up syntax highlighting automatically, powered by Prism React Renderer.

http://localhost:3000
console.log('Every repo must come with a mascot.');

Theming

我们默认使用 Prism 的 Palenight 语法高亮主题。你可在 docusaurus.config.js 配置文件中的 themeConfig 配置项中为 prism 字段设置 theme 属性即可更改为另一个主题。

例如,如果你更喜欢使用 dracula 语法高亮主题的话,配置如下:

docusaurus.config.js
module.exports = {
themeConfig: {
prism: {
theme: require('prism-react-renderer/themes/dracula'),
},
},
};

Because a Prism theme is just a JS object, you can also write your own theme if you are not satisfied with the default. Docusaurus enhances the github and vsDark themes to provide richer highlight, and you can check our implementations for the light and dark code block themes.

Supported Languages

默认情况下,Docusaurus 自动支持对部分 常用编程语言 的语法高亮显示。

警告

某些流行的编程语言(例如 Java、C# 或 PHP)并未默认开启支持。

To add syntax highlighting for any of the other Prism-supported languages, define it in an array of additional languages.

备注

Each additional language has to be a valid Prism component name. For example, Prism would map the language cs to csharp, but only prism-csharp.js exists as a component, so you need to use additionalLanguages: ['csharp']. You can look into node_modules/prismjs/components to find all components (languages) available.

For example, if you want to add highlighting for the PowerShell language:

docusaurus.config.js
module.exports = {
// ...
themeConfig: {
prism: {
additionalLanguages: ['powershell'],
},
// ...
},
};

设置 additionalLanguages 之后需要重启 Docusaurus 才能起作用。

如果要为 Prism 尚不支持的编程语言添加语法高亮的话,则可以覆盖(swizzle)prism-include-languages 组件:

npm run swizzle @docusaurus/theme-classic prism-include-languages

这将在你的 src/theme 目录下生成 prism-include-languages.js 文件。你可以通过编辑 prism-include-languages.js 文件来添加对新的编程语言的语法高亮的支持。

src/theme/prism-include-languages.js
const prismIncludeLanguages = (Prism) => {
// ...

additionalLanguages.forEach((lang) => {
require(`prismjs/components/prism-${lang}`);
});

require('/path/to/your/prism-language-definition');

// ...
};

在你为新的编程语言添加语法高亮功能时,可以参考 Prism 官方的语言定义

代码行高亮

Highlighting with comments

You can use comments with highlight-next-line, highlight-start, and highlight-end to select which lines are highlighted.

```js
function HighlightSomeText(highlight) {
if (highlight) {
// highlight-next-line
return 'This text is highlighted!';
}

return 'Nothing highlighted';
}

function HighlightMoreText(highlight) {
// highlight-start
if (highlight) {
return 'This range is highlighted!';
}
// highlight-end

return 'Nothing highlighted';
}
```
http://localhost:3000
function HighlightSomeText(highlight) {
if (highlight) {
return 'This text is highlighted!';
}

return 'Nothing highlighted';
}

function HighlightMoreText(highlight) {
if (highlight) {
return 'This range is highlighted!';
}

return 'Nothing highlighted';
}

Supported commenting syntax:

StyleSyntax
C-style/* ... */ and // ...
JSX-style{/* ... */}
Bash-style# ...
HTML-style<!-- ... -->

We will do our best to infer which set of comment styles to use based on the language, and default to allowing all comment styles. If there's a comment style that is not currently supported, we are open to adding them! Pull requests welcome. Note that different comment styles have no semantic difference, only their content does.

You can set your own background color for highlighted code line in your src/css/custom.css which will better fit to your selected syntax highlighting theme. The color given below works for the default highlighting theme (Palenight), so if you are using another theme, you will have to tweak the color accordingly.

/src/css/custom.css
:root {
--docusaurus-highlighted-code-line-bg: rgb(72, 77, 91);
}

/* If you have a different syntax highlighting theme for dark mode. */
[data-theme='dark'] {
/* Color which works with dark mode syntax highlighting theme */
--docusaurus-highlighted-code-line-bg: rgb(100, 100, 100);
}

If you also need to style the highlighted code line in some other way, you can target on theme-code-block-highlighted-line CSS class.

Highlighting with metadata string

You can also specify highlighted line ranges within the language meta string (leave a space after the language). To highlight multiple lines, separate the line numbers by commas or use the range syntax to select a chunk of lines. This feature uses the parse-number-range library and you can find more syntax on their project details.

```jsx {1,4-6,11}
import React from 'react';

function MyComponent(props) {
if (props.isBar) {
return <div>Bar</div>;
}

return <div>Foo</div>;
}

export default MyComponent;
```
http://localhost:3000
import React from 'react';

function MyComponent(props) {
if (props.isBar) {
return <div>Bar</div>;
}

return <div>Foo</div>;
}

export default MyComponent;
prefer comments

Prefer highlighting with comments where you can. By inlining highlight in the code, you don't have to manually count the lines if your code block becomes long. If you add/remove lines, you also don't have to offset your line ranges.

- ```jsx {3}
+ ```jsx {4}
function HighlightSomeText(highlight) {
if (highlight) {
+ console.log('Highlighted text found');
return 'This text is highlighted!';
}

return 'Nothing highlighted';
}
```

Below, we will introduce how the magic comment system can be extended to define custom directives and their functionalities. The magic comments would only be parsed if a highlight metastring is not present.

Custom magic comments

// highlight-next-line and // highlight-start etc. are called "magic comments", because they will be parsed and removed, and their purposes are to add metadata to the next line, or the section that the pair of start- and end-comments enclose.

You can declare custom magic comments through theme config. For example, you can register another magic comment that adds a code-block-error-line class name:

module.exports = {
themeConfig: {
prism: {
magicComments: [
// Remember to extend the default highlight class name as well!
{
className: 'theme-code-block-highlighted-line',
line: 'highlight-next-line',
block: {start: 'highlight-start', end: 'highlight-end'},
},
{
className: 'code-block-error-line',
line: 'This will error',
},
],
},
},
};
http://localhost:3000

In JavaScript, trying to access properties on null will error.

const name = null;
console.log(name.toUpperCase());
// Uncaught TypeError: Cannot read properties of null (reading 'toUpperCase')

If you use number ranges in metastring (the {1,3-4} syntax), Docusaurus will apply the first magicComments entry's class name. This, by default, is theme-code-block-highlighted-line, but if you change the magicComments config and use a different entry as the first one, the meaning of the metastring range will change as well.

You can disable the default line highlighting comments with magicComments: []. If there's no magic comment config, but Docusaurus encounters a code block containing a metastring range, it will error because there will be no class name to apply—the highlighting class name, after all, is just a magic comment entry.

Every magic comment entry will contain three keys: className (required), line, which applies to the directly next line, or block (containing start and end), which applies to the entire block enclosed by the two comments.

Using CSS to target the class can already do a lot, but you can unlock the full potential of this feature through swizzling.

npm run swizzle @docusaurus/theme-classic CodeBlock/Line

The Line component will receive the list of class names, based on which you can conditionally render different markup.

Line numbering

You can enable line numbering for your code block by using showLineNumbers key within the language meta string (don't forget to add space directly before the key).

```jsx {1,4-6,11} showLineNumbers
import React from 'react';

function MyComponent(props) {
if (props.isBar) {
return <div>Bar</div>;
}

return <div>Foo</div>;
}

export default MyComponent;
```
http://localhost:3000
import React from 'react';

function MyComponent(props) {
if (props.isBar) {
return <div>Bar</div>;
}

return <div>Foo</div>;
}

export default MyComponent;

交互式代码编辑器

(基于 React Live 实现)

你可以利用 @docusaurus/theme-live-codeblock 插件来创建交互式代码编辑器。首先将该插件添加到项目中。

npm install --save @docusaurus/theme-live-codeblock

你还需要将此插件添加到 docusaurus.config.js 配置文件中。

module.exports = {
// ...
themes: ['@docusaurus/theme-live-codeblock'],
// ...
};

使用此插件时,创建一个代码块并在编程语言标记后面添加 live 字样即可。

```jsx live
function Clock(props) {
const [date, setDate] = useState(new Date());
useEffect(() => {
const timerID = setInterval(() => tick(), 1000);

return function cleanup() {
clearInterval(timerID);
};
});

function tick() {
setDate(new Date());
}

return (
<div>
<h2>It is {date.toLocaleTimeString()}.</h2>
</div>
);
}
```

该代码块将被渲染为一个交互式编辑器。在该编辑器中修改代码的话,在“结果”栏中就能即时看到修改的效果。

http://localhost:3000
实时编辑器
结果
Loading...

Imports

react-live and imports

react-live 代码编辑器是无法直接导入(import)组件的,你必须预先定义并导入(import)组件才能在编辑器中使用。

默认情况下,所有 React 组件都已被导入(import)并可以直接使用了。如果你需要更多额外的组件,请覆盖(swizzle)主题中相应的组件并调整 react-live 导入(import)组件的范围:

npm run swizzle @docusaurus/theme-live-codeblock ReactLiveScope -- --eject
src/theme/ReactLiveScope/index.js
import React from 'react';

const ButtonExample = (props) => (
<button
{...props}
style={{
backgroundColor: 'white',
color: 'black',
border: 'solid red',
borderRadius: 20,
padding: 10,
cursor: 'pointer',
...props.style,
}}
/>
);

// 为 react-live 导入(import)所需要的组件
const ReactLiveScope = {
React,
...React,
ButtonExample,
};

export default ReactLiveScope;

ButtonExample 组件就可以使用了:

http://localhost:3000
实时编辑器
结果
Loading...

Imperative Rendering (noInline)

The noInline option should be used to avoid errors when your code spans multiple components or variables.

```jsx live noInline
const project = 'Docusaurus';

const Greeting = () => <p>Hello {project}!</p>;

render(<Greeting />);
```

Unlike an ordinary interactive code block, when using noInline React Live won't wrap your code in an inline function to render it.

You will need to explicitly call render() at the end of your code to display the output.

http://localhost:3000
实时编辑器
结果
Loading...

Using JSX markup in code blocks

Code block in Markdown always preserves its content as plain text, meaning you can't do something like:

type EditUrlFunction = (params: {
// This doesn't turn into a link (for good reason!)
version: <a href="/docs/versioning">Version</a>;
versionDocsDirPath: string;
docPath: string;
permalink: string;
locale: string;
}) => string | undefined;

If you want to embed HTML markup such as anchor links or bold type, you can use the <pre> tag, <code> tag, or <CodeBlock> component.

<pre>
<b>Input: </b>1 2 3 4{'\n'}
<b>Output: </b>"366300745"{'\n'}
</pre>
http://localhost:3000
Input: 1 2 3 4
Output: "366300745"
MDX is whitespace insensitive

MDX is in line with JSX behavior: line break characters, even when inside <pre>, are turned into spaces. You have to explicitly write the new line character for it to be printed out.

警告

Syntax highlighting only works on plain strings. Docusaurus will not attempt to parse code block content containing JSX children.

Multi-language support code blocks

With MDX, you can easily create interactive components within your documentation, for example, to display code in multiple programming languages and switch between them using a tabs component.

我们没有为实现代码块的多语言支持而开发专用的组件,而是在 classic 主题中实现了一个通用的 <Tabs> 组件,以便将其用于其它非代码场景。

The following example is how you can have multi-language code tabs in your docs. Note that the empty lines above and below each language block are intentional. This is a current limitation of MDX: you have to leave empty lines around Markdown syntax for the MDX parser to know that it's Markdown syntax and not JSX.

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';

<Tabs>
<TabItem value="js" label="JavaScript">

```js
function helloWorld() {
console.log('Hello, world!');
}
```

</TabItem>
<TabItem value="py" label="Python">

```py
def hello_world():
print("Hello, world!")
```

</TabItem>
<TabItem value="java" label="Java">

```java
class HelloWorld {
public static void main(String args[]) {
System.out.println("Hello, World");
}
}
```

</TabItem>
</Tabs>

渲染效果如下:

http://localhost:3000
function helloWorld() {
console.log('Hello, world!');
}

如果你有多个这样的多编程语言代码标签组,并且想要在各标签组之间实现当前所选编程语言的同步,请参阅 同步标签卡的状态章节

Docusaurus npm2yarn remark plugin

Displaying CLI commands in both npm and Yarn is a very common need, for example:

npm install @docusaurus/remark-plugin-npm2yarn

Docusaurus provides such a utility out of the box, freeing you from using the Tabs component every time. To enable this feature, first install the @docusaurus/remark-plugin-npm2yarn package as above, and then in docusaurus.config.js, for the plugins where you need this feature (doc, blog, pages, etc.), register it in the remarkPlugins option. (See Docs configuration for more details on configuration format)

docusaurus.config.js
module.exports = {
// ...
presets: [
[
'@docusaurus/preset-classic',
{
docs: {
remarkPlugins: [
[require('@docusaurus/remark-plugin-npm2yarn'), {sync: true}],
],
},
pages: {
remarkPlugins: [require('@docusaurus/remark-plugin-npm2yarn')],
},
blog: {
// ...
},
},
],
],
};

And then use it by adding the npm2yarn key to the code block:

```bash npm2yarn
npm install @docusaurus/remark-plugin-npm2yarn
```

Using the {sync: true} option would make all tab choices synced. Because the choice is stored under the same namespace npm2yarn, different npm2yarn plugin instances would also sync their choices.

Usage in JSX

Outside of Markdown, you can use the @theme/CodeBlock component to get the same output.

import CodeBlock from '@theme/CodeBlock';

export default function MyReactPage() {
return (
<div>
<CodeBlock
language="jsx"
title="/src/components/HelloCodeTitle.js"
showLineNumbers>
{`function HelloCodeTitle(props) {
return <h1>Hello, {props.name}</h1>;
}`}
</CodeBlock>
</div>
);
}
http://localhost:3000
/src/components/HelloCodeTitle.js
function HelloCodeTitle(props) {
return <h1>Hello, {props.name}</h1>;
}

The props accepted are language, title and showLineNumbers, in the same way as you write Markdown code blocks.

Although discouraged, you can also pass in a metastring prop like metastring='{1-2} title="/src/components/HelloCodeTitle.js" showLineNumbers', which is how Markdown code blocks are handled under the hood. However, we recommend you use comments for highlighting lines.

As previously stated, syntax highlighting is only applied when the children is a simple string.