better-react-mathjax

A simple React component for MathJax

Note: The full documentation is available at https://github.com/fast-reflexes/better-react-mathjax

Up-to-date component for using MathJax in latest React (using functional components and hooks API). Focuses on being versatile and making the use of MathJax in React a pleasant experience without flashes of non-typeset content, both with respect to initial rendering as well as dynamic updates. Simple to use but with many configuration options.

Features

• Supports both MathJax version 2 and 3.
• Supports local copy of MathJax or copy supplied via CDN.
• Small imprint on production bundle with dependencies only for types (image shows a size of 6.18 KB and 2.3 KB gzipped in a NextJS project analyzed with their bundle analyzer).

• Built in a modular fashion on top of MathJax with direct access to MathJax via the MathJax configuration.
• Use MathJax functionality either through the MathJax component or by yourself through the MathJaxBaseContext.
• Either put your math into the DOM with React first and let MathJax typeset afterwards (v. 2 and 3), or typeset with MathJax first and add it to the DOM afterwards (v. 3 only).
• Hide your components before they are typeset to avoid flashes of non-typeset content and make the use of MathJax a pleasant experience.
• Complete - no other dependencies related to MathJax are needed to enable the use of MathJax in your React app.

Basic workflow

Installation

Add this library manually as a dependency to package.json...

dependencies: {
    "better-react-mathjax": "^2.0.3"
}

... and then run npm install or let npm or yarn do it for you, depending on which package manager you have chosen to use:

# npm
npm install better-react-mathjax

# yarn
yarn add better-react-mathjax

Usage

better-react-mathjax introduces two React components - MathJaxContext and MathJax. For MathJax to work with React:

1. Wrap your entire app in a MathJaxContext component (only use one in your app).

const App = () => {

   return (
       <MathJaxContext>
           <!-- APP CONTENT -->
       </MathJaxContext>
   )
}

1. Then simply use MathJax components at different levels for the actual math.

const Component = () => {

   return (
       <div>
           <MathJax>{ /* math content */ }</MathJax>
           <h3>This is a header</h3>
           <MathJax>
               <div>
                   <h4>This is a subheader</h4>
                   <span>{ /* math content */ }</span>
                   <h4>This is a second subheader</h4>
                   <span>{ /* math content */ }</span>
                   ...
               </div>
           </MathJax>
           <p>
               This is text which involves math <MathJax>{ /* math content */ }</MathJax> inside the paragraph.
           </p>
       </div>
   )
}

In the typical case, the content of a MathJax component can be everything from a subtree of the DOM to a portion of text in a long paragraph. If you have a lot of math, try to wrap as much as possible in the same MathJax component. The MathJaxContext is responsible for downloading MathJax and providing it to all wrapped MathJax components that typeset math. By default, MathJaxContext imports MathJax from a CDN which allows for use of Latex, AsciiMath and MathML with MathJax version 2 and Latex and MathML with the default MathJax version 3 with HTML output for both. If you need something else or want to host your own copy of MathJax, read more about the src attribute of the MathJaxContext below.

Examples

The first 3 are basic examples with zero configuration standard setup using MathJax version 3 with default MathJax config and no extra options. Note that sandboxes tend to be slower than use in a real environment.

Example 1: Basic example with Latex

Standard setup using MathJax version 3 with default MathJax config and no extra options.

export default function App() {

    return (
        <MathJaxContext>
              <h2>Basic MathJax example with Latex</h2>
              <MathJax>{"\\(\\frac{10}{4x} \\approx 2^{12}\\)"}</MathJax>
        </MathJaxContext>
    );
    
}

Sandbox: https://codesandbox.io/s/better-react-mathjax-basic-example-latex-bj8gd

Example 2: Basic example with AsciiMath

Using AsciiMath with the default version 3 import requires adding an extra loader (see the MathJax documentation for further information). AsciiMath uses the same display mode on the entire page, which is display math by default. It can be changed to inline math by adding asciimath: { displaystyle: false } to the input config.

export default function App() {
    const config = {
        loader: { load: ["input/asciimath"] }
    };
    
    return (
        <MathJaxContext config={config}>
            <h2>Basic MathJax example with AsciiMath</h2>
            <MathJax>{"`frac(10)(4x) approx 2^(12)`"}</MathJax>
        </MathJaxContext>
    );
}

Sandbox: https://codesandbox.io/s/better-react-mathjax-basic-example-asciimath-ddy4r

Example 3: Basic example with MathML

MathML is supported natively by a few but far from all browsers. It might be problematic to use with Typescript (no types for MathML included in this package).

export default function App() {
    return (
        <MathJaxContext>
            <h2>Basic MathJax example with MathML</h2>
            <MathJax>
                <math>
                    <mrow>
                        <mrow>
                            <mfrac>
                                <mn>10</mn>
                                <mi>4x</mi>
                            </mfrac>
                        </mrow>
                        <mo>&asymp;</mo>
                        <mrow>
                            <msup>
                                <mn>2</mn>
                                <mn>12</mn>
                            </msup>
                        </mrow>
                    </mrow>
                </math>
            </MathJax>
        </MathJaxContext>
    );
}

Sandbox: https://codesandbox.io/s/better-react-mathjax-basic-example-mathml-20vv6

Example 4: Elaborate example with Latex

Sandbox: https://codesandbox.io/s/better-react-mathjax-example-latex-3vsr5

Example 5: Elaborate example with AsciiMath

Sandbox: https://codesandbox.io/s/better-react-mathjax-example-asciimath-p0uf1

Example 6: Elaborate example with MathML

Make sure to study the comments in this file as MathML processing is a little bit different from Latex and AsciiMath.

Sandbox link: https://codesandbox.io/s/better-react-mathjax-example-mathml-nprxz

Example 7: Elaborate example with optimal settings for dynamic updates with Latex

This example shows a configuration that in some particular cases has proven to result in a very smooth experience with no flashes of non-typeset content. It is by no means recommended as a first attempt and can be tried if you experience problems with flashes of non-typeset content, long waiting times or other undesired behaviour. Especially for those using MathJax version 2, some of the configuration options can be used as an inspiration.

Sandbox link: https://codesandbox.io/s/better-react-mathjax-example-latex-optimal-8nn9n

TypeScript types

This project has both its own types and MathJax types included in the package. For MathJax version 2, a refactored and updated version of @types/mathjax is used whereas for MathJax version 3, this package depends on the types from mathjax-full. Nonetheless, none of the logic from these are used in this project so after building production code and tree-shaking, these dependencies will not affect the size of the final bundle. If you would prefer a separate @types package for this project, please make a suggestion about this in an issue on the project Github page. Note also that issues with the MathJax 2 types can be addressed and updated within this project whereas the types from mathjax-full are used unaltered.

API

The following three properties can be set on both the MathJaxContext and MathJax components. When set on a MathJaxContext component, they apply to all wrapped MathJax components except those on which the property in question is set on the individual MathJax component, which then takes precedence.

Note: MathJax3Object and MathJax3Config are aliases for MathJaxObject and MathJaxConfig as exported by mathjax-full.

---

hideUntilTypeset: "first" | "every" | undefined

Controls whether the content of the MathJax component should be hidden until after typesetting is finished.

Default: undefined (no content is hidden at any time)

renderMode: "pre" | "post" | undefined

Controls how typesetting by MathJax is done in the DOM. Typically, using the setting of post works well but in rare cases it might be desirable to use pre for performance reasons or to handle very special cases of flashes of non-typeset content.

Default: post

typesettingOptions: { fn: TypesettingFunction, options: OptionList | undefined } | undefined

Used to control typesetting when renderMode is set to pre. Controls which typesetting function to use and an optional object with typesetting details.

Default: undefined (no conversion function is supplied which throws an error when renderMode is pre)

MathJaxContext component

---

config: MathJax2Config | MathJax3Config | undefined

Controls MathJax and is passed to MathJax as its config.

Default: undefined (default MathJax configuration is used)

MathJax configuration object. Make sure it corresponds to the version used. More information can be found in the docs.

src: string | undefined

The location of MathJax.

Default: undefined (default CDN https://cdnjs.cloudflare.com is used)

Local or remote url to fetch MathJax from. More information about hosting your own copy of MathJax can be found in the MathJax documentation and more in particular on the better-react-mathjax Github page.

A source url may contain both some specific file and some query parameters corresponding to a configuration which, in turn, governs which additional assets MathJax fetches. The default sources used when this property is omitted are the same as those listed in the MathJax instruction (however from a different CDN).

version: 2 | 3 | undefined

MathJax version to use. Must be synced with any config passed.

Default: 3

Version of MathJax to use. If set, make sure that any configuration and url to MathJax uses the same version. If src is not specified, setting versionto 2 currently makes use of version 2.7.9 and setting it to 3 uses 3.2.0.

onStartUp: (mathJax: MathJax2Object | MathJax3Object) => void) | undefined

Callback to be called when MathJax has loaded successfully but before the MathJax object has been made available to wrapped MathJax components. The MathJax object is handed as an argument to this callback which is a good place to do any further configuration which cannot be done through the config object.

Default: undefined

onLoad: () => void) | undefined

Callback to be called when MathJax has loaded successfully and after the MathJax object has been made available to the wrapped MathJax components.

Default: undefined

onError: (error: any) => void) | undefined

Callback to handle errors in the startup phase when MathJax is loaded.

Default: undefined

MathJax component

---

inline: boolean | undefined

Whether the wrapped content should be in an inline or block element.

Note: Currently only MathML and Latex can switch between inline mode and math mode in the same document. This means that AsciiMath will use the document default for content, no matter the setting of this property. The property will still affect the wrapper nonetheless.

Default: false

onInitTypeset: () => void) | undefined

Callback for when the content has been typeset for the first time.

Default: undefined

onTypeset: () => void) | undefined

Callback for when the content has been typeset (not only initially).

Default: undefined

text: string | undefined

Required and only used when renderMode is set to pre. Should be the math string to convert without any delimiters. Requires typesettingOptions to be set and version to be 3. If renderMode is post, this property is ignored.

Default: undefined

dynamic: boolean | undefined

Indicates whether the content of the MathJax component may change after initial rendering.

Default: false

---

Any additional props will be spread to the root element of the MathJax component which is a span with display set to inline when the inline property is set to true, otherwise block. The display can be overridden via style prop if needed (then the inline property does not affect the wrapper). A ref is not possible to set as this functionality is used by the MathJax component itself.

Custom use of MathJax directly

You can use the underlying MathJax object directly (not through the MathJax component) if you want as well. The following snippet illustrates how to use MathJaxBaseContext to accomplish this.

// undefined or MathJaxSubscriberProps with properties version, hideUntilTypeset, renderMode, typesettingOptions and promise
const mjContext = useContext(MathJaxBaseContext)
if(mjContext)
  mjContext.promise.then(mathJaxObject => { /* do work with the MathJax object here */ })

This requires only a MathJaxContext, supplying the MathJaxBaseContext, to be in the hierarchy. The object passed from the promise property is the MathJax object for the version in use.

Sandbox example: https://codesandbox.io/s/better-react-mathjax-custom-example-latex-e5kym

MathJax documentation

• Version 3: https://docs.mathjax.org/en/latest/
• Version 2: https://docs.mathjax.org/en/v2.7-latest/

Github

Read full documentation, file problems or contribute on Github: https://github.com/fast-reflexes/better-react-mathjax

License

This project is licensed under the terms of the MIT license.