The unified plugin used to highlight code block in html with Prism.

Usage

This package is ESM only. unified >= 10 is needed to use it. If running on the server side, NodeJS needs to be greater than 12

import { unified } from "unified";
import rehype from "rehype";
import remarkParse from "remark-parse";
import remarkRehype from "remark-rehype";
import rehypePrism from "rehype-prism";
import rehypeStringify from "rehype-stringify";

// you have to load css manual
import "prismjs/themes/prism-coy.css";
import "prismjs/plugins/line-numbers/prism-line-numbers.css";

// load languages manual
// import 'prismjs/components/prism-{language}'
import "prismjs/components/prism-go";
import "prismjs/components/prism-java";
import "prismjs/components/prism-python";

// parse markdown to html
unified()
  .use(remarkParse)
  .use(remarkRehype)
  // it should be after rehype
  .use(rehypePrism, { plugins: ["line-numbers"] })
  .use(rehypeStringify)
  .parse(/* markdown string */);
// .processSync(/* markdown string */)

// parse code block in html string
rehype().use(rehypePrism).use(rehypeStringify).parse(/* html string */);
// .processSync(/* html string */)

Server Side Render

PrismJS will auto highlight all code at pre code after browser document loaded.

Disabled prism autoHighlight before import 'rehype-prism'. there are two way to do this:

• set the window.Prism = { manual: true }

• use the attribute data-manual on the <script> element you used for prism.

  <script src="prism.js" data-manual></script>

Some plugins will not work. Because it's only work in browser.

Load Plugins

The names to use can be found here.

Plugins Reimplemented By rehype-prism

The table list plugins that cannot running on the server side. Therefor it has been re-implemented by rehype-prism.

Plugin Name
line-numbers
toolbar
copy-to-clipboard

I haven't tested all prism plugins. If there are another plugins not work, submit issue on github.

Load More Languages

• Use babel-plugin-prismjs.
• Use loadLanguages() provided by prismjs.(don't use loadLanguages() with Webpack or another bundler)
• Import language manual. e.g. import 'prismjs/components/prism-yaml.js'

Load Themes

• If you use babel-plugin-prismjs. import 'prismjs' will auto load the theme setted in babel-plugin-prismjs config.
• Import theme css manual. e.g. import 'prismjs/themes/prism-coy.css'

See More

shiki is another code highlight tools that support unified. I recommend you try it. It's new, but better suited for modern front-end projects than Prismjs.

This does not mean that I will give up maintaining this library. If you need this library and have any issue, let me know it.

Contributing & Development

If there is any doubt, it is very welcome to discuss the issue together.