A simple React component for 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": "^2.0.2"
}

... 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>
   )
}

2. 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.

Display math and inline math

Both Latex, AsciiMath and MathML have the notion of display math and inline math where display math uses a style and font where the math is allowed to take up more space

Inline math should be used when math is typeset in the middle of text, which then puts some restrictions on space and style

These styles can be set on individual instances of math in Latex and MathML by the use of different pre-configured delimiters, but in AsciiMath, all the math in an app has to use the same style which is set in the configuration (display math by default). On top of this, the MathJax component has a property inline which controls whether the wrapper element added by the MathJax component uses inline or block display. Since a MathJax component can contain a lot of other things than just a single portion of math, it is important to understand that the inline prop is NOT synonymous with inline math since the former controls an element which may contain a lot of things whereas the latter always controls the typesetting of a specific string of math. Therefore, always use configuration and delimiters to control whether to use display math or inline math and use the inline prop to coordinate with the previous setting and control the appearance of the MathJax component itself. Study the elaborate examples below for more insights.

Exceptions to the above rule is when the MathJax component prop renderMode has the value pre in which case one MathJax component becomes synonymous with a single piece of math (given as the text prop) whereby the inline property controls the math mode of the output. The impact of the inline prop on the wrapper element will be ignored if a style that overrides display is added to a MathJax component.

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

Under the hood

The MathJaxContext component downloads MathJax and provides it to all users of the MathJaxBaseContext, which includes MathJax components. A MathJax component typesets its content only once initially, if the dynamic flag is not set, in which case the content is typeset every time a change might have occurred. To avoid showing the user flashes of non-typeset content, the MathJax component does its work in a layout effect, which runs "before the browser has a chance to paint". Nevertheless, since typesetting operations are asynchronous, both because the MathJax library needs to be downloaded but also because MathJax should typeset asynchronously to not block the UI if it has a lot to typeset, the typesetting taking place before the browser paints the updates cannot be guaranteed. In most situations however, it should.

The MathJax library by default typesets the entire page when it has been downloaded, unless instructed explicitly not to do so (check instructions on how to do this for version 2 here and for version 3 here). However, given React and its dynamic nature, with existing content being rerendered and new content being added, math likely needs to be typeset more often than that; at a minimum when a component is mounted and sometimes also as a result of dynamic updates of an existing component. Since this often doesn't coincide with initial page load, math rerendered or added after this moment (for example when showing a new page or component) would not get typeset. This is where the MathJax component plays an important part by explicitly typesetting its content whenever a change might have occurred. It is recommended to use MathJax components and not only rely on automatic typesetting on startup.

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. You can import the configurations and types of the MathJax objects from versions 2 and 3 as MathJax2Config, MathJax2Object, MathJax3Config and MathJax3Object.

The MathJax types are not always helpful and the user should pay attention even if the compiler does not complain. First of all, several of the types from mathjax-full contain catch-all properties of the form [s: string]: any which effectively allows any props to be passed in. Hence, adding a MathJax 2 configuration to a MathJaxContext using MathJax version 3 will not result in a compile error but instead be accepted even though most of the props won't have the desired effect in MathJax 3.

Also, due to how TypeScript handles excess properties, if a configuration is given in a variable (as opposed to in a literal) where any property matches a property of the required type, the remaining props will be silently ignored. Since MathJax versions share a few configuration properties, it is therefore also possible that a MathJax 3 configuration may be given to a MathJaxContext using MathJax 2 without compiler errors. This can however be avoided by always using literals in which case excess properties are handled differently.

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. The most useful setting here is first since the longest delay in typesetting is likely to occur on page load when MathJax hasn't loaded yet. Nonetheless, with a large amount of math on a page, MathJax might not be able to typeset fast enough in which case non-typeset content might be shown to the user; in this case the setting of every might be handy.

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

• first: The MathJax component is hidden until its content has been typeset the first time after which the component remains visible throughout its lifetime.

• every: The same behaviour as when this property is set to first, but in addition, the MathJax component is now hidden and made visible every time it is typeset. With renderMode set to pre this has no effect and is treated as first. When renderMode is set to post, the component is typeset anew on every render. When MathJax is able to typeset fast enough (which is most often the case), the updates will be seamless and the hiding will be invisible to the human eye. When this is not the case this setting might result in "blinking" content as an alternative to flashes of non-typeset content.

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

• post: All children of the MathJax component are added to the DOM by React first and then MathJax processes the wrapped content (in the DOM). This implies that MathJax cannot know if the content has changed or not between renderings and so typesetting takes place on every render. This mode might give rise to flashes of non-typeset content since the content could enter the DOM before MathJax has typeset it (if MathJax doesn't typeset fast enough). In this renderMode MathJax can inspect the context in the DOM and adapt its output to it in different ways (for example in terms of font size).

• pre: Math is passed via the text property (only strings), which must be set with math without delimiters, and is processed by MathJax before it is inserted into the DOM. This mode also requires typesettingOptions to be set with the name of the function to use for the typesetting as well as an optional configuration object with typesetting details. In this renderMode, MathJax only typesets when the text property changes. Since MathJax cannot look at the context (in the DOM) of the math, limited automatic adaptation to surrounding content can be accomplished and fine-tuning might have to be done via the optional options object of the typesettingOptions property. Note: The pre value can only be used with MathJax version 3.

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)

• fn: The name of the MathJax function to use for typesetting. This is only used, and must be specified, when renderMode is set to pre and should be one of the following strings: tex2chtml, tex2chtmlPromise, tex2svg, tex2svgPromise, tex2mml, tex2mmlPromise, mathml2chtml, mathml2chtmlPromise, mathml2svg, mathml2svgPromise, mathml2mml, mathml2mmlPromise , asciimath2chtml, asciimath2chtmlPromise, asciimath2svg, asciimath2svgPromise, asciimath2mml or asciimath2mmlPromise. The value is the name of a function that MathJax generates based on the input configuration, as given to the wrapping MathJaxContext, as per the docs. For example, for the tex2chtml function to be available, the configuration given to the MathJaxContext component must (explicitly or by use of default) contain a Latex input processor and an HTML output processor.

• options: An object with additional parameters to control the typesetting when renderMode is set to pre. Since this typesetting is done outside of the DOM context in which the resulting math will be inserted, MathJax cannot adapt the output to the surrounding content, which is why this can be done manually by the typesetting function. More information about this object can be found in the the docs.

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). This means that for version 2, the fetched resource (MathJax.js?config=TeX-MML-AM_CHTML) includes support for Latex, MML and AsciiMath with HTML output by default, and for version 3, the fetched resource (tex-mml-chtml.js) supports MML and Latex with HTML output. These correspond to some typical and broad use of MathJax in the browser. If you have a use case where you, using standalone MathJax, would have to use a different source url, then you have to manually supply such a url (local or remote) here. This, in analogy to how you would modify the script import to adjust to your needs in a plain HTML environment with direct use of MathJax. Read more about different configurations here (for MathJax 3) and here (for MathJax 2).

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. This marks the last step of the startup phase in the MathJaxContext component when MathJax is loaded. Can be used to sync page loading state along with onInitTypeset callbacks on 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. When renderMode is post, this refers to the wrapper component that this MathJax component uses (the user might still have both display and inline math inside). If renderMode is set to pre this property applies to both the wrapper component and the content which will be typeset as inline math if this property is set to true and as display math otherwise.

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. Can typically be used for hiding content or showing a loading spinner in a coordinated way across different elements until all are in a representative state.

Default: undefined

onTypeset(() => void) | undefined

Callback for when the content has been typeset (not only initially). Can typically be used for hiding content or showing a loading spinner in a coordinated way across different elements until all are in a representative state. Only used when the dynamic flag is set. Similarly to onInitTypeset, this callback also fires on initial typesetting. If the dynamic is not set, this callback is effectively reduced to having the same effect as onInitTypeset. When the dynamic flag is set, this callback runs after every typesetting, which takes place on every render if renderMode is set to post, and when the text prop changes when renderMode is set to pre.

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. When set to true, typesetting should be done repeatedly (every render with renderMode set to post and whenever the text property changes with renderMode set to pre). With this property set to false, only initial typesetting will take place and any changes of the content will not get typeset.

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

Fighting flashes of non-typeset content

Using MathJax, as is, is as seen from the basic examples above fairly simple, but the real challenge is to use it in a way so that the user doesn't see flashes of non-typeset content. Apart from making MathJax available to React in a simple and straightforward way, this is what this library focuses on.

Static content

Static content does not have the dynamic property set to true and is typeset once only when the component mounts. If the component remounts, the procedure repeats. Before the content is typeset, the user may see the raw content which might be a negative experience. There are several ways to solve this:

• Set hideUntilTypeSet to first on individual MathJax components or on the MathJaxContext.
• Coordinate hiding with onInitTypeset to show bigger blocks or the entire page once all MathJax components have finished the initial typesetting. Coordinate with MathJaxContext via the onStartUp or onLoad callback.

Dynamic content

Dynamic content might be harder to work with since it, per definition, updates several times during the time a MathJax component is mounted. With this goal, the dynamic property should be set to true which implies that typesetting will be attempted repeatedly (after every render if renderMode is set to post and when the text property changes if renderMode is set to pre). If not handled correctly, updates might look bad to the user if the content is visible before typesetting. As indicated above in the "Under the hood" section, this should usually not happen since MathJax typesets the content in a layout effect. However, MathJax typesets content asynchronously and there might be occasions where the typesetting takes place after the browsers has already updated. This might happen if you have a lot of math on a page for example. Apart from the general considerations below, there are a few strategies to try in order to solve this problem.

Note: these measures should only be taken to battle flashes of non-typeset content where proven necessary.

• Set hideUntilTypeset to every. This might result in a short blink instead but may be a preferable option in some cases than to show content that is not typeset. Try to put your MathJax components outside of parents that often rerender to avoid unnecessary rerenderings (and accompanying blinking).
• Set renderMode to pre. With this mode, the MathJax component typesets the math content before inserting it into the DOM which should remove any flashes of non-typeset content in some scenarios, however not in all as indicated below. One downside with this setting is that MathJax cannot access the context of the math and so it cannot adapt generated content to it; manual fine-tuning might be necessary even though this is not always the case.

General considerations regarding flashes of non-typeset content

• Currently, MathJax version 3 might give rise to subtle flickering in both Chrome and Safari on dynamic updates. This is not connected to this package and does not seem to be related to the actual typesetting but how the CSS is injected into and applied by the browser. Alas, flickering may in some cases be visible despite described methods. In this case, the remedy is to use version 2, where seamless typesetting is still possible in all attempted browsers. Note that this kind of flickering is not a flash of non-typeset content but merely some styling adjustment that is done after typesetting.
• The best cross-browser experience for normal use cases at this time is achieved with version 2, with disabled fast-preview and processSectionDelay set to 0 for a smooth experience. This is done by including "fast-preview": { disabled: true } in the MathJax config object given to the MathJaxContext and adding mathJax => mathJax.Hub.processSectionDelay = 0 as the onStartup callback to the same. Coordinate initial typesetting with hideUntilTypeset set to first and / or onInitTypeset callbacks. Feel free to check out Example 7 above where this is shown, but remember, don't use it if you dont need to.

General Considerations (don't skip)

• Don't nest MathJax components since this will result in the same math content being typeset multiple times by different MathJax components. This is unnecessary work.

• React has an unresolved issue with DOM nodes with mixed literal and expression content, such as <div> This is literal and { "this is in an expression" }</div>, when used together with DOM manipulation via refs. For this reason, when the dynamic property is set to true, always make sure that the expression containing math is not mixed with literal content. The following list summarizes this:

  • Don't: <p>An example is the equation ${num}x^4 = 100$</p> (expression with math not in separate element nor expression)
  • Don't: <p>An example is the equation { "$${num}x^4 = 100$" }</p> (expression with math not in separate element)
  • Don't: <p>An example is the equation <span>${num}x^4 = 100$</span></p> (expression with math not in separate expression - mixed inside span)
  • Don't: <p>An example is the equation <span> { "$${num}x^4 = 100$" }</span></p> (expression with math not in separate element - note the space in the beginning of the span)
  • Do: <p>{ "An example is the equation $${num}x^4 = 100$" }</p> (expression with math in separate element and expression)
  • Do: <p>An example is the equation <span>{ "$${num}x^4 = 100$" }</span></p> (expression with math in separate element and expression)

  For static content, this does not matter since it is the interplay between how React handles updates to this content and the manipulation of the same via refs that causes problems.

• Don't wrap any content that may rerender on its own. State changes must come from outside the wrapping MathJax component; if only its children rerender but not the parent MathJax component, math will not be typeset anew. If you have this situation, simply wrap smaller portions of math content in MathJax components instead until the state lies outside all MathJax components.

• In most scenarios, renderMode should be set to post. Use pre when you use dynamic updates and it is crucial that MathJax doesn't typeset all content after every render due to performance reasons, or if you have some other very particular use case when using post is causing you problems.

• If you do not achieve the effect you want, play around with what content you wrap in MathJax components and where in the hierarchy they are kept. You can always replace a larger (more complex) content wrapped in a MathJax component with one or several smaller parts of it wrapped in several MathJax components.

• Remember that MathJax automatically does initial typesetting on the whole document both in version 2 and 3. This can be turned off (check instructions on how to do this for version 2 here and for version 3 here) but with it, a document can be typeset with only a MathJaxContext component. This, however, is not the intended use of the better-react-mathjax library and removes many of the additional options as well as the possibility to typeset content that is not present on the page on initial load; it is therefore recommended to always use MathJax components as well.

• React doesn't translate all HTML5 entities which can cause problems with MathJax. There are often multiple entities for the same symbol and if your chosen entity gives you problems in MathML, try another one.

• The documented API above is only the additional functionality offered in the layer provided by this library. Most other options and behaviours are properties of the MathJax library itself and thus configurable with the config object.

Questions and answers

• Q: Is it fine to use multiple MathJaxContext components in my app?

  A: The MathJaxContext is stateful and will only download MathJax once, no matter if you use multiple instances or unmount and then remount it. Nonetheless, it is more clear from a coding perspective to use a single MathJaxContext in your app which is not unmounted during the lifetime of your app. Therefore, it is recommended to wrap your entire app in a MathJaxContext and then not use the MathJaxContext component anywhere else.

• Q: I have a lot of math and it takes forever for the math to be typeset, what can I do?

  A: This library queues every MathJax component as a sequential typesetting update in MathJax. MathJax can typeset the entire page in no time, but when some of the overhead of typesetting is multiplied many times over, MathJax becomes slower. To solve this, consider using fewer MathJax components and replace many uses of MathJax component with a single MathJax component wrapping a larger portion of a DOM sub-tree. Then the overhead from typesetting many times over will be less and the typesetting will be faster and smoother. The division of math into different MathJax components is ultimately a function of app structure, what parts are updated when, where React state lies and whether math content is dynamic or not, but with a lot of math on a page, it is often the case that we may group expressions. Also remember as a general guideline that loading / showing too much content at the same time in an app is bad from many perspectives and perhaps considering dividing your app into smaller portions which are not all shown at the same time might be a good idea.

• Q: I have only static non-dynamic math, do I have to use MathJax components?

  A: If you haven't configured MathJax to NOT perform typesetting of the whole page on initial load, it will do so and given that all of your math are present on the page at this time, it will be typeset properly. However, depending on you app, even if subsequent updates of parts of the page done by React will not insert new math, the old math might be rewritten to the page in which case it would need to be typeset again. You can always experiment with only using a MathJaxContext and rely on initial typesetting to do all the work you need but in general, it is recommended and more failsafe to rely on MathJax components which will explicitly typeset anew upon rendering.

Last but not least ...

MathJax was not written for use in React and React was not written with MathJax in mind so we have to massage them into getting along and working in tandem!

Compatibility

Tested with:

• MacOS Catalina 10.15.7:

  • Firefox 86.0.1 (64-bit)
  • Chrome 89.0.4389.90 (64-bit)
  • Safari 14.0.3

• Android 9:

  • Firefox 87.0.0-rc.1
  • Chrome 89.0.4389.105
  • Duck Duck Go 5.78.1
  • Opera 62.3.3146.57763
  • Edge 46.02.4.5152
  • Samsung Internet 13.2.3.2

• iOS:

  • Chrome 87.4280.77
  • Safari 14.4.1

• Windows

  • Firefox 87.0.(64-bit)
  • Chrome 89.0.4389.90 (64-bit)
  • Opera 75.0.3969.93
  • Edge 89.0.774.63 (64-bit)

Wish list

• Investigate whether a custom adaptor (https://github.com/mathjax/MathJax-src/tree/master/ts/adaptors) that can write to React's virtual DOM is a good idea. MathJax's litedom adaptor is probably fairly close already.
• Investigate SSR rendering with mathjax-full (e.g. send preprocessed MathJax nodes to the frontend).
• Test and upgrade list of tested browsers
• Perhaps create some ready-configured mathjax contexts (such as Latex2SVGMathJax3Context, Latex2HTMLMathJax3Context etc..)
• Check whether we could refrain from downloading mathjax and use the bundled mathjax instead? COULD require significant negative impact on production bundle for all other use cases.

MathJax documentation

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

Github

File problems or contribute on Github: https://github.com/fast-reflexes/better-react-mathjax

Changelog

• v. 1.0.0
  • Initial Release
• v. 1.0.1
  • Removed types imported from @types/mathjax and mathjax-full due to several reasons. Custom type declarations will be supplied instead.
• v. 1.0.2
  • Readded types with custom types for MathJax2 based on @types/mathjax and types from mathjax-full for MathJax3.
• v. 1.0.3
  • Fixed missing license.
  • Corrected function signature on MathJax component.
  • Updated default MathJax 3 version provided by CDN to using v. 3.2.0.
  • Updated MathJax 3 types used to v. 3.2.0.
  • Added content to API documentation on property src.
  • Added installation instructions.
  • Added information about AsciiMath display mode.
  • Corrected typo in API documentation on version property.
• v. 2.0.0
  • Breaking change: can no longer use MathJax versions 2 and 3 side by side in different MathJaxContexts. This did typically not work as intended before either and even though this change is breaking, it should not affect many users, if any. Docs have been updated and MathJaxContext now throws an error if it has been initialized with one version and another MathJaxContext (later or simultaneous) has a different value on the version prop.
  • Added support for hot reload by always setting dynamic to true when dynamic is not explicitly set to false and process.env.NODE_ENV is not production.
  • Honoring possible style settings of style.visibility in MathJax component when visibility is not controlled by the component itself.
  • Corrected sandbox example with AsciiMath where Latex default delimiter was used instead of AsciiMath delimiter (still worked because Latex is loaded by default as well).
  • Improved documentation with clarifications:
    • The entire app should be wrapped in the only MathJaxContext that should exist in a project.
    • How to deal with the situation when you have a lot of math on your page.
    • The features available with the default imports from CDN.
    • Difference between inline and display math.
  • Added Q & A section to documentation.
  • Changed all checks for undefined to use typeof X === "undefined" instead of X === undefined.
  • Added support for esm modules as well as the previous cjs modules.
  • Added language tags on code samples
• v. 2.0.1
  • React 18 compatibility
  • Small fix in type for typesettingOptions.options which now does not accept display (should be set via inline prop instead)
• v. 2.0.2
  • Updated default MathJax 3 version provided by CDN to using v. 3.2.2.
  • Project maintenance.
  • Added documentation on how to turn off automatic typesetting on startup.

Migration guides

• v1 to v2:
  • Remove all simultaneous use of MathJax version 2 and 3 in the same app and use only one version of MathJax per loaded page. This means that even if you unmount the MathJaxContext and then remount it, it must have the same version both times. If you load a new page context (e.g. not just change page in a SPA (single-page application)) the version can be determined anew. If you need to use both versions side by side, file an issue on the project Github page.

License

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