Making a Custom Build of MathJax
MathJax provides a number of combined components that load everything you need to run MathJax with a given input and output format. Still, you might find that none of the ones we provide fully suit your needs, and that you would like to include additional components in the build, or perhaps want to include customized configuration options.
You can use the MathJax component build tools to make your own custom component that has exactly the pieces and configuration that you want. You can also use them to make a custom extension, for example a TeX input extension, that takes advantage of the components already loaded, but implements additional functionality. These possibilities are described in Building a Custom Component below.
It is also possible to make a completely custom build of MathJax that doesn’t use the MathJax components at all, but includes direct calls to the MathJax source files. This is described in A Custom MathJax Build below.
If you wish to include MathJax as part of a larger project, you can use either of the techniques to do that, and make a webpacked file that includes your own project code as well as MathJax.
Getting Things Ready
Your first step is to download a copy of MathJax via npm or
git, as described in the section on Acquiring the MathJax Code.
If you use
npm, you will want to install themathjax-fullpackage rather than themathjaxpackage, since the former includes all the source code, in both its original and compiled forms, along with the webpacked components.
If you use
git, be sure to run the commands to compile and make the components, as listed in Getting MathJax via git.
In either case, you should have a js, an es5, and a
components directory, either in the node_modules/mathjax-full
directory (for npm installations) or in the main directory (for
git installations).
Your second step is to obtain the tools needed to package your custom
code using webpack. Use the commands
npm install webpack
npm install webpack-cli
npm install terser-webpack-plugin
npm install babel-loader
npm install @babel/core
npm install @babel/preset-env
to install webpack and its needed libraries. Once this is done,
you should be able to make the components described below. The
building instructions assume you used npm to acquire MathJax; if
you used git, then you will need to remove
node_modules/mathjax-full from the paths that include them.
Building a Custom Component
MathJax comes with a number of predefined components, and you can use their definitions as a starting point for your own custom component. There are also custom component examples (with documentation) in the MathJax web demos repository, which are similar to the ones described here.
There are two kinds of components you could build:
A combined component that brings together several other components (the
tex-chtmlcomponent is a combined component)
A extension component that contains what is needed for one feature and can be loaded along with other components to add that feature to MathJax.
We describe how you can create each of these below. In both cases, you should create a directory to hold your component’s support files. You will need the main control file for the component (that includes the code that defines the component), and a webpack control file that will tell MathJax’s build tools how to handle your component. These will be discussed in the sections below.
A Custom Combined Component
After downloading a copy of MathJax as described in the section on
Getting Things Ready, make the directory for your component and
cd to that directory. We will assume the directory is called
custom-mathjax for this discussion.
For this example, we will create a custom build that has the TeX input
jax and the SVG output jax, and we will load the newcommand,
ams, and configmacros extensions, but will not include
require or autoload, so the user will not be able load any
additional TeX extensions. This component also includes the
contextual menu.
The Control File
Create a javascript file to house the component and call it
custom-mathjax.js. The file should contain the following code (we
assume here that you used npm to install MathJax. If not, you may
need to adjust the locations in the require() commands).
//
// Initialize the MathJax startup code
//
require('mathjax-full/components/src/startup/lib/startup.js');
//
// Get the loader module and indicate the modules that
// will be loaded by hand below
//
const {Loader} = require('mathjax-full/js/components/loader.js');
Loader.preLoad(
'loader', 'startup',
'core',
'input/tex-base',
'[tex]/ams',
'[tex]/newcommand',
'[tex]/configmacros',
'output/svg', 'output/svg/fonts/tex.js',
'ui/menu'
);
//
// Load the components that we want to combine into one component
// (the ones listed in the preLoad() call above)
//
require('mathjax-full/components/src/core/core.js');
require('mathjax-full/components/src/input/tex-base/tex-base.js');
require('mathjax-full/components/src/input/tex/extensions/ams/ams.js');
require('mathjax-full/components/src/input/tex/extensions/newcommand/newcommand.js');
require('mathjax-full/components/src/input/tex/extensions/configmacros/configmacros.js');
require('mathjax-full/components/src/output/svg/svg.js');
require('mathjax-full/components/src/output/svg/fonts/tex/tex.js');
require('mathjax-full/components/src/ui/menu/menu.js');
//
// Update the configuration to include any updated values
//
const {insert} = require('mathjax-full/js/util/Options.js');
insert(MathJax.config, {
tex: {
packages: {'[+]': ['ams', 'newcommand', 'configmacros']}
}
});
//
// Loading this component will cause all the normal startup
// operations to be performed
//
require('mathjax-full/components/src/startup/startup.js');
This loads the various components that we want to include in the combined component, including the standard startup code so that the usual startup process is included.
The Webpack Configuration
Next, create the file webpack.config.js that includes the
following:
const PACKAGE = require('mathjax-full/components/webpack.common.js');
module.exports = PACKAGE(
'custom-mathjax', // the name of the package to build
'../node_modules/mathjax-full/js', // location of the mathjax library
[], // packages to link to
__dirname, // our directory
'.' // where to put the packaged component
);
This file gives the name that will be used for this component
(custom-mathjax in this case), a pointer to where the MathJax
javascript code is to be found (adjust this to suit your setup), an
array of components that we assume are already loaded when this one is
loaded (none in this case), the directory name we are working in
(always __dirname), and the directory where we want the final
packaged component to go (the default is the
mathjax-full/es5 directory, but we set it to the directory
containing the source files, and the component will end with
.min.js).
Most of the real work is done by the
mathjax-full/components/webpack.common.js file, which is included in
the first line here.
Building the Component
Once these two files are ready, you are ready to build the component. First, make sure that you have obtained the needed tools as described in Getting Things Ready above. Then you should be able to use the command
node ../node_modules/mathjax-full/components/bin/makeAll
to process your custom build. You should end up with a file
custom-mathjax.min.js in the directory with the other files. If
you put this on your web server, you can load it into your web pages
in place of loading MathJax from a CDN. This file will include all
that you need to run MathJax on your pages. Just add
<script src="custom-mathjax.min.js" id="MathJax-script" async></script>
to your page and you should be in business (adjust the URL to point to
wherever you have placed the custom-mathjax.min.js file).
Configuring the Component
Note that you can still include a MathJax = {...} definition in
your web page before loading this custom MathJax build if you want to
customize the configuration for a specific page. You could also
include configuration within the component itself, as we did for the
TeX packages array. This will override any page-provided
configuration, however, so if you want to provide non-standard
defaults that can still be overridden in the page, use
//
// Update the configuration to include any updated values
//
const {insert} = require('mathjax-full/js/util/Options.js');
insert(MathJax.config, {tex: {packages: {'[+]': ['ams', 'newcommand', 'configmacros']}}}, false);
MathJax.config = insert({
// your default options here
}, MathJax.config);
which will update the TeX packages, and then merge the user’s
configuration options into your defaults and set
MathJax.config to the combined options.
Fonts for CommonHTML
If you include the CommonHTML output jax in your custom build, the
actual web fonts are not included in the webpacked file, so you will
probably need to include fontURL in the chtml
block of your configuration and have it provide a URL where the fonts
can be found. They are in the
mathjax-full/es5/output/chtml/fonts/woff-v2 directory, and
you can put them on your server, or simply point fontURL to one of
the CDN directories for the fonts.
A Custom Extension
Making a custom extension is very similar to making a custom combined component. The main difference is that the extension may rely on other components, so you need to tell the build system about that so that it doesn’t include the code from those other components. You also don’t load the extension file directly (like you do the combined component above), but instead include it in the load array of the loader configuration block, and MathJax loads it itself, as discussed below.
For this example, we make a custom TeX extension that defines new TeX commands implemented by javascript functions.
The commands implemented here provide the ability to generate
MathML token elements from within TeX by hand. This allows more
control over the content and attributes of the elements produced. The
macros are \mi, \mo, \mn, \ms, and \mtext, and
they each take an argument that is the text to be used as the content
of the corresponding MathML element. The text is not further processed
by TeX, but the extension does convert sequences of the form
\uNNNN (where the N are hexadecimal digits) into the
corresponding unicode character; e.g., \mi{\u2460} would produce
U+2460, a circled digit 1, as the content of an mi element.
The Extension File
After downloading a copy of MathJax as described in the section on
Getting Things Ready, create a directory for the extension named
custom-extension and cd to it. Then create the file mml.js
containing the following text:
import {Configuration} from '../node_modules/mathjax-full/js/input/tex/Configuration.js';
import {CommandMap} from '../node_modules/mathjax-full/js/input/tex/SymbolMap.js';
import TexError from '../node_modules/mathjax-full/js/input/tex/TexError.js';
/**
* This function prevents multi-letter mi elements from being
* interpreted as TEXCLASS.OP
*/
function classORD(node) {
this.getPrevClass(node);
return this;
}
/**
* Convert \uXXXX to corresponding unicode characters within a string
*/
function convertEscapes(text) {
return text.replace(/\\u([0-9A-F]{4})/gi, (match, hex) => String.fromCharCode(parseInt(hex,16)));
}
/**
* Allowed attributes on any token element other than the ones with default values
*/
const ALLOWED = {
style: true,
href: true,
id: true,
class: true
};
/**
* Parse a string as a set of attribute="value" pairs.
*/
function parseAttributes(text, type) {
const attr = {};
if (text) {
let match;
while ((match = text.match(/^\s*((?:data-)?[a-z][-a-z]*)\s*=\s*(?:"([^"]*)"|(.*?))(?:\s+|,\s*|$)/i))) {
const name = match[1], value = match[2] || match[3]
if (type.defaults.hasOwnProperty(name) || ALLOWED.hasOwnProperty(name) || name.substr(0,5) === 'data-') {
attr[name] = convertEscapes(value);
} else {
throw new TexError('BadAttribute', 'Unknown attribute "%1"', name);
}
text = text.substr(match[0].length);
}
if (text.length) {
throw new TexError('BadAttributeList', 'Can\'t parse as attributes: %1', text);
}
}
return attr;
}
/**
* The mapping of control sequence to function calls
*/
const MmlMap = new CommandMap('mmlMap', {
mi: ['mmlToken', 'mi'],
mo: ['mmlToken', 'mo'],
mn: ['mmlToken', 'mn'],
ms: ['mmlToken', 'ms'],
mtext: ['mmlToken', 'mtext']
}, {
mmlToken(parser, name, type) {
const typeClass = parser.configuration.nodeFactory.mmlFactory.getNodeClass(type);
const def = parseAttributes(parser.GetBrackets(name), typeClass);
const text = convertEscapes(parser.GetArgument(name));
const mml = parser.create('node', type, [parser.create('text', text)], def);
if (type === 'mi') mml.setTeXclass = classORD;
parser.Push(mml);
}
});
/**
* The configuration used to enable the MathML macros
*/
const MmlConfiguration = Configuration.create(
'mml', {handler: {macro: ['mmlMap']}}
);
The comments explain what this code is doing. The main piece needed
to make it a TeX extension is the Configuration created in the
last few lines. It creates a TeX package named mml that handles
macros through a CommandMap named mmlMap that is defined just
above it. That command map defines five macros described at the
beginning of this section, each of which is tied to a method named
mmlToken in the object that follows, passing it the name of the
MathML token element to create. The mmlToken method is the one
that is called by the TeX parser when the \mi and other macros are
called. It gets the argument to the macro, and any optional
attributes, and creates the MathML element with the attributes, using
the argument as the text of the element.
The Webpack Configuration
Next, create the file webpack.config.js that includes the
following:
const PACKAGE = require('mathjax-full/components/webpack.common.js');
module.exports = PACKAGE(
'mml', // the name of the package to build
'../node_modules/mathjax-full/js', // location of the mathjax library
[ // packages to link to
'components/src/core/lib',
'components/src/input/tex-base/lib'
],
__dirname, // our directory
'.' // where to put the packaged component
);
This file gives the name that will be used for this component (mml
in this case), a pointer to where the MathJax javascript code is to be
found (adjust this to suit your setup), an array of components that we
assume are already loaded when this one is loaded (the core and
tex-base components in this case), the directory name we are
working in (always __dirname), and the directory where we want the
final packaged component to go (the default is the
mathjax-full/es5 directory, but we set it to the directory
containing the source files, and the component will end with
.min.js).
Most of the real work is done by the
mathjax-full/components/webpack.common.js file, which is included in
the first line here.
Building the Extension
Once these two files are ready, you are ready to build the component. First, make sure that you have obtained the needed tools as described in Getting Things Ready above. Then you should be able to use the command
node ../node_modules/mathjax-full/components/bin/makeAll
to process your custom build. You should end up with a file
mml.min.js in the directory with the other files. If
you put this on your web server, you can load it as a component by
putting it in the load array of the loader block of your
configuration, as descrinbed below.
Loading the Extension
To load your custom extension, you will need to tell MathJax where it
is located, and include it in the file to be loaded on startup.
MathJax allows you to define paths to locations where your extensions
are stored, and then you can refer to the extensions in that location
by using a prefix that represents that location. MathJax has a
pre-defined prefix, mathjax that is the default prefix when none
is specified explicitly, and it refers to the location where the main
MathJax file was loaded (e.g., the file tex-svg.js, or
startup.js).
You can define your own prefix to point to the location of your
extensions by using the paths object in the loader block of
your configuration. In our case (see code below), we add a custom
prefix, and have it point to the URL of our extension (in this case,
the same directory as the HTML file that loads it, represented by the
URL .). We use the custom prefix to specify
[custom]/mml.min.js in the load array so that our extension
will be loaded.
Finally, we add the mml extension to the packages array in the
tex block of our configuration via the special notation {'[+]':
[...]} that tells MathJax to append the given array to the existing
packages array that is already in the configuration by default.
So this uses all the packages that were already specified, plus our
new mml package that is defined in our extension.
The configuration and loading of MathJax now looks something like this:
<script>
MathJax = {
loader: {
load: ['[custom]/mml.min.js'],
paths: {custom: '.'}
},
tex: {
packages: {'[+]': ['mml']}
}
};
</script>
<script type="text/javascript" id="MathJax-script" async
src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js">
</script>
You should change the custom: '.' line to point to the actual URL for
your server.
This example loads the tex-chtml.js combined component, so the TeX
input is already loaded when our extension is loaded. If you are
using startup.js instead, and including input/tex in the
load array, you will need to tell MathJax that your extension
depends on the input/tex extension so that it waits to load your
extension until after the TeX input jax is loaded. To do that, add a
dependencies block to your configuration like the following:
<script>
MathJax = {
loader: {
load: ['input/tex', 'output/chtml', '[custom]/mml.min.js'],
paths: {custom: '.'},
dependencies: {'[custom]/mml.min.js': ['input/tex']}
},
tex: {
packages: {'[+]': ['mml']}
}
};
</script>
<script type="text/javascript" id="MathJax-script" async
src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/startup.js">
</script>
This example can be seen live in the MathJax 3 demos repository.
A Custom MathJax Build
It is possible to make a completely custom build of MathJax that is not based on other MathJax components at all. The following example shows how to make a custom build that provides a function for obtaining the speech string for a given TeX math string. This example is similar to one in the MathJax3 demos repository.
After downloading a copy of MathJax as described in the section on
Getting Things Ready, create a directory called mathjax-speech and
cd into it.
The Custom Build File
Create the custom MathJax file named mathjax-speech.js containing
the following:
//
// Load the desired components
//
const mathjax = require('mathjax-full/js/mathjax.js').mathjax; // MathJax core
const TeX = require('mathjax-full/js/input/tex.js').TeX; // TeX input
const MathML = require('mathjax-full/js/input/mathml.js').MathML; // MathML input
const browser = require('mathjax-full/js/adaptors/browserAdaptor.js').browserAdaptor; // browser DOM
const Enrich = require('mathjax-full/js/a11y/semantic-enrich.js').EnrichHandler; // semantic enrichment
const Register = require('mathjax-full/js/handlers/html.js').RegisterHTMLHandler; // the HTML handler
const AllPackages = require('mathjax-full/js/input/tex/AllPackages').AllPackages; // all TeX packages
const STATE = require('mathjax-full/js/core/MathItem.js').STATE;
const sreReady = require('mathjax-full/js/a11y/sre.js').sreReady(); // SRE promise;
//
// Register the HTML handler with the browser adaptor and add the semantic enrichment
//
Enrich(Register(browser()), new MathML());
//
// Initialize mathjax with a blank DOM.
//
const html = mathjax.document('', {
sre: {
speech: 'shallow', // add speech to the enriched MathML
},
InputJax: new TeX({
packages: AllPackages.filter((name) => name !== 'bussproofs'), // Bussproofs needs an output jax
macros: {require: ['', 1]} // Make \require a no-op since all packages are loaded
})
});
//
// The user's configuration object
//
const CONFIG = window.MathJax || {};
//
// The global MathJax object
//
window.MathJax = {
version: mathjax.version,
html: html,
sreReady: sreReady,
tex2speech(tex, display = true) {
const math = new html.options.MathItem(tex, html.inputJax[0], display);
return mathjax.handleRetriesFor(() => math.convert(html, STATE.CONVERT)).then(() => {
let speech = '';
math.root.walkTree(node => {
const attributes = node.attributes.getAllAttributes();
console.log(attributes);
if (!speech && attributes['data-semantic-speech'] &&
!attributes['data-semantic-parent']) {
speech = attributes['data-semantic-speech'];
}
});
return speech || 'no speech text generated';
});
}
};
//
// Perform ready function, if there is one
//
if (CONFIG.ready) {
sreReady.then(CONFIG.ready);
}
Unlike the component-based example above, this custom build calls on
the MathJax source files directly. The require commands at the
beginning of the file load the needed objects, and the rest of the
code instructs MathJax to create a MathDocument object for
handling the conversions that we will be doing (using a TeX input
jax), and then defines a global MathJax object that has the
tex2speech() function that our custom build offers.
The Webpack Configuration
Next, create the file webpack.config.js that includes the
following:
const PACKAGE = require('mathjax-full/components/webpack.common.js');
module.exports = PACKAGE(
'mathjax-speech', // the name of the package to build
'../node_modules/mathjax-full/js', // location of the mathjax library
[], // packages to link to
__dirname, // our directory
'.' // where to put the packaged component
);
This file gives the name that will be used for this component
(mathjax-speech in this case), a pointer to where the MathJax
javascript code is to be found (adjust this to suit your setup), an
array of components that we assume are already loaded when this one is
loaded (none, since this is a self-contained build), the directory
name we are working in (always __dirname), and the directory where
we want the final packaged component to go (the default is the
mathjax-full/es5 directory, but we set it to the directory
containing the source files, and the component will end with
.min.js).
Most of the real work is done by the
mathjax-full/components/webpack.common.js file, which is included in
the first line here.
Building the Custom File
Once these two files are ready, you are ready to make your custom build. First, make sure that you have obtained the needed tools as described in Getting Things Ready above. Then you should be able to use the command
node ../node_modules/mathjax-full/components/bin/makeAll
to process your custom build. You should end up with a file
mathjax-speech.min.js in the directory with the other files. it
will contain just the parts of MathJax that are needed to implement
the MathJax.tex2speech() command defined in the file above.
Note that this is not enough to do normal typesetting (for example, no
output jax has been included), so this is a minimal file for producing
the speech strings from TeX input.
Using the File in a Web Page
If you put the mathjax-speech.min.js file on your web server, you
can load it into your web pages in place of loading MathJax from a
CDN. This fill will include all that you need to use the
MathJax.tex2speech() command in your pages. Just add
<script src="mathjax-speech.min.js" id="MathJax-script" async></script>
to your page (adjust the URL to point to wherever you have placed the
custom-mathjax.min.js file). Then you can use javascript calls
like
const speech = await MathJax.tex2speech('\\sqrt{x^2+1}', true);
to obtain a text string that contains the speech text for the square root given in the TeX string.
Note, however, that the Speech-Rule Engine (SRE) that underlies the
speech generation loads asynchronously, so you have to be sure that
SRE is ready before you make such a call. The mathjax-speech.js
file provides two ways of handling the synchronization with SRE. The
first is to use the global MathJax variable to include a
ready() function that is called when SRE is ready. For
example,
window.speechReady = false;
window.MathJax = {
ready: () => {
window.speechReady = true;
}
};
would set the global variable speechReady to true when SRE is
ready to run (so you can check that value to see if speech can be
generated yet). A more sophisticated ready() function could
allow you to queue translations to be performed, and when SRE is ready,
it performs them. Alternatively, if you have a user interface that
allows users to transform TeX expressions, for example, then you could
initially disable to buttons that trigger speech generation, and use
the ready() function to enable them. That way, the user can’t
ask for speech translation until it can be produced.
The second method of synchronizing with SRE is through the fact that
the code sets MathJax.sreReady to a promise that is resolves
when SRE is ready, which you can use to make sure SRE is ready when you
want to do speech generation. For example
function showSpeech(tex, display = false) {
MathJax.sreReady = MathJax.sreReady.then(async () => {
const speech = await MathJax.tex2speech(tex, display);
const output = document.getElementById('speech');
output.innerHTML = '';
output.appendChild(document.createTextNode(speech));
});
}
provides a function that lets you specify a TeX string to translate,
and then (asynchronously) generates the speech for it and displays it
as the contents of the DOM element with id="speech" in the page.