A lean Prism highlighter component for React
Comes with everything to render Prismjs highlighted code directly to React (Native) elements, global-pollution-free!

[![Maintenance Status][maintenance-image]](#maintenance-status) ## Why? Maybe you need to render some extra UI with your Prismjs-highlighted code, or maybe you'd like to manipulate what Prism renders completely, or maybe you're just using Prism with React and are searching for an easier, global-pollution-free way? Then you're right where you want to be! ## How? This library tokenises code using Prism and provides a small render-props-driven component to quickly render it out into React. This is why it even works with React Native! It's bundled with a modified version of Prism that won't pollute the global namespace and comes with [a couple of common language syntaxes](./packages/generate-prism-languages/index.ts#L9-L23). _(There's also an [escape-hatch](https://github.com/FormidableLabs/prism-react-renderer#prism) to use your own Prism setup, just in case)_ It also comes with its own [VSCode-like theming format](#theming), which means by default you can easily drop in different themes, use the ones this library ships with, or create new ones programmatically on the fly. _(If you just want to use your Prism CSS-file themes, that's also no problem)_ ## Table of Contents - [Installation](#installation) - [Usage](#usage) - [Custom Language Support](#custom-language-support) - [Basic Props](#basic-props) - [children](#children) - [language](#language) - [code](#code) - [Advanced Props](#advanced-props) - [theme](#theme) - [prism](#prism) - [Children Function](#children-function) - [state](#state) - [prop getters](#prop-getters) - [`getLineProps`](#getlineprops) - [`getTokenProps`](#gettokenprops) - [Utility Functions](#utility-functions) - [`normalizeTokens`](#normalizetokens) - [`useTokenize`](#usetokenize) - [Theming](#theming) - [LICENSE](#license) - [Maintenance Status](#maintenance-status) ## Installation This module is distributed via npm which is bundled with node and should be installed as one of your project's `dependencies`: ```sh # npm npm install --save prism-react-renderer # yarn yarn add prism-react-renderer # pnpm pnpm add prism-react-renderer ``` > Prism React Renderer has a peer dependency on `react` ### Usage Prism React Renderer has a named export for the `` component along with `themes`. To see Prism React Render in action with base styling check out `packages/demo` or run `pnpm run start:demo` from the root of this repository. ```tsx import React from "react" import ReactDOM from "react-dom/client" import { Highlight, themes } from "prism-react-renderer" import styles from 'styles.module.css' const codeBlock = ` const GroceryItem: React.FC = ({ item }) => { return (

## {item.name}

Price: {item.price}

Quantity: {item.quantity}

); } ` export const App = () => ( {({ className, style, tokens, getLineProps, getTokenProps }) => (

            {tokens.map((line, i) => (

                {i + 1}
                {line.map((token, key) => (

                ))}

            ))}

)} ) ReactDOM.createRoot(document.getElementById("root") as HTMLElement) .render() ``` ### Custom Language Support By default `prism-react-renderer` only includes a [base set of languages](https://github.com/FormidableLabs/prism-react-renderer/blob/c914fdea48625ba59c8022174bb3df1ed802ce4d/packages/generate-prism-languages/index.ts#L9-L23) that Prism supports. **Depending on your app's build system you may need to `await` the `import` or use `require` to ensure `window.Prism` exists before importing the custom languages.** You can add support for more by including their definitions from the main `prismjs` package: ```js import { Highlight, Prism } from "prism-react-renderer"; (typeof global !== "undefined" ? global : window).Prism = Prism await import("prismjs/components/prism-applescript") /** or **/ require("prismjs/components/prism-applescript") ``` ## Basic Props This is the list of props that you should probably know about. There are some [advanced props](#advanced-props) below as well. Most of these [advanced props](#advanced-props) are included in the `defaultProps`. ### children > `function({})` | _required_ This is called with an object. Read more about the properties of this object in the section "[Children Function](#children-function)". ### language > `string` | _required_ This is the language that your code will be highlighted as. You can see a list of all languages that are supported out of the box [here](./packages/generate-prism-languages/index.ts#L9-L23). Not all languages are included and the list of languages that are currently is a little arbitrary. You can use the [escape-hatch](https://github.com/FormidableLabs/prism-react-renderer#prism) to use your own Prism setup, just in case, or [add more languages to the bundled Prism.](https://github.com/FormidableLabs/prism-react-renderer#faq) ### code > `string` | _required_ This is the code that will be highlighted. ## Advanced Props ### theme > `PrismTheme` | _optional; default is vsDark_ If a theme is passed, it is used to generate style props which can be retrieved via the prop-getters which are described in "[Children Function](#children-function)". Read more about how to theme `prism-react-renderer` in the section "[Theming](#theming)". ### prism > `prism` | _optional; default is the vendored version_ This is the [Prismjs](https://github.com/PrismJS/prism) library itself. A vendored version of Prism is provided (and also exported) as part of this library. This vendored version doesn't pollute the global namespace, is slimmed down, and doesn't conflict with any installation of `prismjs` you might have. If you're only using `Prism.highlight` you can choose to use `prism-react-renderer`'s exported, vendored version of Prism instead. But if you choose to use your own Prism setup, simply pass Prism as a prop: ```jsx // Whichever way you're retrieving Prism here: import Prism from 'prismjs/components/prism-core'; ``` ## Children Function This is where you render whatever you want to based on the output of ``. You use it like so: ```js const ui = ( {highlight => ( // use utilities and prop getters here, like highlight.className, highlight.getTokenProps, etc.

    {/* more jsx here */}

)} ); ``` The properties of this `highlight` object can be split into two categories as indicated below: ### state These properties are the flat output of ``. They're generally "state" and are what you'd usually expect from a render-props-based API. | property | type | description | | ----------- | ----------- | ---------------------------------------------------------------------------------------------------------------------------- | | `tokens` | `Token[][]` | This is a doubly nested array of tokens. The outer array is for separate lines, the inner for tokens, so the actual content. | | `className` | `string` | This is the class you should apply to your wrapping element, typically a `

    `                                             |

    A "Token" is an object that represents a piece of content for Prism. It has a `types` property, which is an array
    of types that indicate the purpose and styling of a piece of text, and a `content` property, which is the actual
    text.

    You'd typically iterate over `tokens`, rendering each line, and iterate over its items, rendering out each token, which is a piece of
    this line.

    ### prop getters

    > See
    > [Kent C. Dodds' blog post about prop getters](https://blog.kentcdodds.com/how-to-give-rendering-control-to-users-with-prop-getters-549eaef76acf)

    These functions are used to apply props to the elements that you render. This
    gives you maximum flexibility to render what, when, and wherever you like.

    You'd typically call these functions with some dictated input and add on all other
    props that it should pass through. It'll correctly override and modify the props
    that it returns to you, so passing props to it instead of adding them directly is
    advisable.

    | property        | type           | description                                                                                           |
    | --------------- | -------------- | ----------------------------------------------------------------------------------------------------- |
    | `getLineProps`  | `function({})` | returns the props you should apply to any list of tokens, i.e. the element that contains your tokens. |
    | `getTokenProps` | `function({})` | returns the props you should apply to the elements displaying tokens that you render.                 |

    #### `getLineProps`

    You need to add a `line` property (type: `Token[]`) to the object you're passing to
    `getLineProps`; It's also advisable to add a `key`.

    This getter will return you props to spread onto your line elements (typically `s`).

    It will typically return a `className` (if you pass one it'll be appended), `children`,
    `style` (if you pass one it'll be merged). It also passes on all other props you pass
    to the input.

    The `className` will always contain `.token-line`.

    #### `getTokenProps`

    You need to add a `token` property (type: `Token`) to the object you're passing to
    `getTokenProps`; It's also advisable to add a `key`.

    This getter will return you props to spread onto your token elements (typically `s`).

    It will typically return a `className` (if you pass one it'll be appended), `children`,
    `style` (if you pass one it'll be merged). It also passes on all other props you pass
    to the input.

    The `className` will always contain `.token`. This also provides full compatibility with
    your old Prism CSS-file themes.

    ## Utility Functions

    ### `useTokenize`

    > `(options: TokenizeOptions) => Token[][]`

    ```ts
    type TokenizeOptions = {
      prism: PrismLib
      code: string
      grammar?: PrismGrammar
      language: Language
    }

    ```

    This is a React hook that tokenizes code using Prism. It returns an array of tokens that can be rendered using the built-in `` component or your own custom component. It uses `normalizeTokens` internally to convert the tokens into a shape that can be rendered.

    - `prism: PrismLib`: the Prism library to use for tokenization. This can be the vendored version of Prism that is included with `prism-react-renderer` or a custom version of Prism that you have configured.

    - `code: string`: a string containing the code to tokenize.
    - `grammar?: PrismGrammar`: a Prism grammar object to use for tokenization. If this is omitted, the tokens will just be normalized. A grammar can be obtained from `Prism.languages` or by importing a language from `prismjs/components/`.
    - `language: Language`: the language to use for tokenization. This should be a language that Prism supports.

    ### `normalizeTokens`

    > `(tokens: (PrismToken | string)[]) => Token[][]`

    Takes an array of Prism’s tokens and groups them by line, converting strings into tokens. Tokens can become recursive in some cases which means that their types are concatenated. Plain-string tokens however are always of type `plain`.

    - `PrismToken` is an internal alias for `Token` exported by `prismjs` and is defined [here](https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/prismjs/index.d.ts#L347).

    - `Token` is an internal object that represents a slice of tokenized content for Prism with three properties:
      - `types: string[]`: an array of types that indicate the purpose and styling of a piece of text
      - `content: string`: the content of the token
      - `empty: boolean`: a flag indicating whether the token is empty or not.

    ## Theming

    The `defaultProps` you'd typically apply in a basic use-case, contain a default theme.
    This theme is [vsDark](./packages/prism-react-renderer/src/themes/vsDark.ts).

    While all `className`s are provided with ``, so that you could use your good
    old Prism CSS-file themes, you can also choose to use `prism-react-renderer`'s themes like so:

    ```jsx
    import { Highlight, themes } from 'prism-react-renderer';

    ```

    These themes are JSON-based and are heavily inspired by VSCode's theme format.

    Their syntax, expressed in Flow looks like the following:

    ```js
    {
      plain: StyleObj,
      styles: Array<{
        types: string[],
        languages?: string[],
        style: StyleObj
      }>
    }
    ```

    The `plain` property provides a base style-object. This style object is directly used
    in the `style` props that you'll receive from the prop getters, if a `theme` prop has
    been passed to ``.

    The `styles` property contains an array of definitions. Each definition contains a `style`
    property, that is also just a style object. These styles are limited by the `types`
    and `languages` properties.

    The `types` properties is an array of token types that Prism outputs. The `languages`
    property limits styles to highlighted languages.

    When converting a Prism CSS theme it's mostly just necessary to use classes as
    `types` and convert the declarations to object-style-syntax and put them on `style`.

    ## LICENSE

    MIT

    ## Maintenance Status

    **Active:** Formidable is actively working on this project, and we expect to continue for work for the foreseeable future. Bug reports, feature requests and pull requests are welcome.

    [maintenance-image]: https://img.shields.io/badge/maintenance-active-green.svg