Version: 2.0.0-alpha.39

Markdown Features

Documentation is one of your product's interfaces with your users. A well-written and well-organized set of docs helps your users understand your product quickly. Our aligned goal here is to help your users find and understand the information they need, as quickly as possible.

Docusaurus 2 uses modern tooling to help you compose your interactive documentations with ease. You may embed React components, or build live coding blocks where your users may play with the code on the spot. Start sharing your eureka moments with the code your audience cannot walk away from. It is perhaps the most effective way of attracting potential users.

In this section, we'd like to introduce you to the tools we've picked that we believe will help you build powerful documentation. Let us walk you through with an example.

Note: All the following content assumes you are using docusaurus-preset-classic.

Markdown is a syntax that enables you to write formatted content in a readable syntax. The standard Markdown syntax is supported and we use MDX as the parsing engine, which can do much more than just parsing Markdown. More on that later.

Create a markdown file, greeting.md, and place it under the docs directory.

website # root directory of your site
├── docs
│   └── greeting.md
├── src
│   └── pages
├── docusaurus.config.js
├── ...

In the top of the file, specify id the title in the front matter, so that Docusaurus will pick them up correctly when generating your site.

---
id: greeting
title: Hello
---
## Hello from Docusaurus
Are you ready to create the documentation site for your open source project?
### Headers
will show up on the table of contents on the upper right
So that your users will know what this page is all about without scrolling down or even without reading too much.
### Only h2 and h3 will be in the toc
The headers are well-spaced so that the hierarchy is clear.
- lists will help you
- present the key points
- that you want your users to remember
  - and you may nest them
    - multiple times

This will render in the browser as follows:

Hello from Docusaurus

Are you ready to create the documentation site for your open source project?

Headers

will show up on the table of contents on the upper right

So that your users will know what this page is all about without scrolling down or even without reading too much.

Only h2 and h3 will be in the toc

The headers are well-spaced so that the hierarchy is clear.

lists will help you
present the key points
that you want your users to remember
- and you may nest them
  - multiple times

Markdown Headers

Documents use the following markdown header fields that are enclosed by a line --- on either side:

id: A unique document id. If this field is not present, the document's id will default to its file name (without the extension).
title: The title of your document. If this field is not present, the document's title will default to its id.
hide_title: Whether to hide the title at the top of the doc. By default it is false.
hide_table_of_contents: Whether to hide the table of contents to the right. By default it is false.
sidebar_label: The text shown in the document sidebar and in the next/previous button for this document. If this field is not present, the document's sidebar_label will default to its title.
custom_edit_url: The URL for editing this document. If this field is not present, the document's edit URL will fall back to editUrl from options fields passed to docusaurus-plugin-content-docs.
keywords: Keywords meta tag for the document page, for search engines.
description: The description of your document, which will become the <meta name="description" content="..."/> and <meta property="og:description" content="..."/> in <head>, used by search engines. If this field is not present, it will default to the first line of the contents.
image: Cover or thumbnail image that will be used when displaying the link to your post.

Example:

---
id: doc-markdown
title: Markdown Features
hide_title: false
hide_table_of_contents: false
sidebar_label: Markdown :)
custom_edit_url: https://github.com/facebook/docusaurus/edit/master/docs/api-doc-markdown.md
description: How do I find you when I cannot solve this problem
keywords:
  - docs
  - docusaurus
image: https://i.imgur.com/mErPwqL.png
---

Embedding React components

Docusaurus has built-in support for MDX, which allows you to write JSX within your Markdown files and render them as React components.

Note: While both .md and .mdx files are parsed using MDX, some of the syntax are treated slightly differently. For the most accurate parsing and better editor support, we recommend using the .mdx extension for files containing MDX syntax. Let's rename the previous file to greeting.mdx

Try this block here:

export const Highlight = ({children, color}) => (
  <span
    style={{
      backgroundColor: color,
      borderRadius: '2px',
      color: '#fff',
      padding: '0.2rem',
    }}>
    {children}
  </span>
);
<Highlight color="#25c2a0">Docusaurus green</Highlight> and <Highlight color="#1877F2">Facebook blue</Highlight> are my favorite colors.
I can write **Markdown** alongside my _JSX_!

Notice how it renders both the markup from your React component and the Markdown syntax:

Docusaurus green and Facebook blue are my favorite colors.

I can write Markdown alongside my JSX!

You can also import your own components defined in other files or third-party components installed via npm! Check out the MDX docs to see what other fancy stuff you can do with MDX.

Referencing other documents

If you want to reference another document file, you should use the name of the document you want to reference. Docusaurus will convert the file path to be the final website path (and remove the .md).

For example, if you are in doc2.md and you want to reference doc1.md and folder/doc3.md:

I am referencing a [document](doc1.md). Reference to another [document in a folder](folder/doc3.md)
[Relative document](../doc2.md) referencing works as well.

One benefit of this approach is that the links to external files will still work if you are viewing the file on GitHub.

Syntax highlighting

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

```jsx
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.

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

By default, the Prism syntax highlighting theme we use is Palenight. You can change this to another theme by passing theme field in prism as themeConfig in your docusaurus.config.js.

For example, if you prefer to use the dracula highlighting theme:

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

By default, Docusaurus comes with this subset of commonly used languages.

To add syntax highlighting for any of the other Prism supported languages, install the prismjs npm package, then swizzle the CodeBlock component and add the desired language(s) there.

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

// src/theme/CodeBlock/index.js
import Prism from 'prism-react-renderer/prism';
(typeof global !== 'undefined' ? global : window).Prism = Prism;
require('prismjs/components/prism-powershell');

Line highlighting

You can bring emphasis to certain lines of code by specifying line ranges after the language meta string (leave a space after the language).

```jsx {3}
function HighlightSomeText(highlight) {
  if (highlight) {
    return 'This text is highlighted!';
  }
  return 'Nothing highlighted';
}
```

function HighlightSomeText(highlight) {
  if (highlight) {
    return 'This text is highlighted!';
  }
  return 'Nothing highlighted';
}

To accomplish this, Docusaurus adds the docusaurus-highlight-code-line class to the highlighted lines. You will need to define your own styling for this CSS, possibly in your src/css/custom.css with a custom background color which is dependent on your selected syntax highlighting theme. The color given below works for the default highlighting theme (Palenight), so if you are using another theme will have to tweak the color accordingly.

/* /src/css/custom.css */
.docusaurus-highlight-code-line {
  background-color: rgb(72, 77, 91);
  display: block;
  margin: 0 calc(-1 * var(--ifm-pre-padding));
  padding: 0 var(--ifm-pre-padding);
}

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;
```

import React from 'react';
function MyComponent(props) {
  if (props.isBar) {
    return <div>Bar</div>;
  }
  return <div>Foo</div>;
}
export default MyComponent;

Interactive code editor

(Powered by React Live)

You can create an interactive coding editor with the @docusaurus/theme-live-codeblock plugin.

First, add the plugin to your package.

npm
Yarn

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

You will also need to add the plugin to your docusaurus.config.js.

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

To use the plugin, create a code block with live attached to the language meta string.

```jsx live
function Clock(props) {
  const [date, setDate] = useState(new Date());
  useEffect(() => {
    var timerID = setInterval(() => tick(), 1000);
    return function cleanup() {
      clearInterval(timerID);
    };
  });
  function tick() {
    setDate(new Date());
  }
  return (
    <div>
      <h2>It is {date.toLocaleTimeString()}.</h2>
    </div>
  );
}
```

The code block will be rendered as an interactive editor. Changes to the code will reflect on the result panel live.

Live Editor
function Clock(props) {
  const [date, setDate] = useState(new Date());
  useEffect(() => {
    var timerID = setInterval(() => tick(), 1000);

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

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

  return (
    <div>
      <h2>It is {date.toLocaleTimeString()}.</h2>
    </div>
  );
}function Clock(props) {
  const [date, setDate] = useState(new Date());
  useEffect(() => {
    var timerID = setInterval(() => tick(), 1000);
    return function cleanup() {
      clearInterval(timerID);
    };
  });
  function tick() {
    setDate(new Date());
  }
  return (
    <div>
      <h2>It is {date.toLocaleTimeString()}.</h2>
    </div>
  );
}
Result
It is 14:51:09.

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 switching between them using a tabs component.

Instead of implementing a dedicated component for multi-language support code blocks, we've implemented a generic Tabs component in the classic theme so that you can use it for other non-code scenarios as well.

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 is 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
  defaultValue="js"
  values={[
    { label: 'JavaScript', value: 'js', },
    { label: 'Python', value: 'py', },
    { label: 'Java', value: 'java', },
  ]
}>
<TabItem value="js">
```js
function helloWorld() {
  console.log('Hello, world!');
}
```
</TabItem>
<TabItem value="py">
```py
def hello_world():
  print 'Hello, world!'
```
</TabItem>
<TabItem value="java">
```java
class HelloWorld {
  public static void main(String args[]) {
    System.out.println("Hello, World");
  }
}
```
</TabItem>
</Tabs>

And you will get the following:

JavaScript
Python
Java

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

You may want to implement your own <MultiLanguageCode /> abstraction if you find the above approach too verbose. We might just implement one in future for convenience.

Hello from Docusaurus

Headers

Only h2 and h3 will be in the toc

#Markdown Headers

#Embedding React components

#Referencing other documents

#Syntax highlighting

#Line highlighting

#Interactive code editor

It is 14:51:09.

#Multi-language support code blocks