"""Allow `MathJax`_ to be used to display math in Sphinx's HTML writer.
This requires the MathJax JavaScript library on your webserver/computer.
.. _MathJax: https://www.mathjax.org/
"""
from __future__ import annotations
import json
from types import NoneType
from typing import TYPE_CHECKING, cast
from docutils import nodes
import sphinx
from sphinx.errors import ExtensionError
from sphinx.locale import _
from sphinx.util.math import get_node_equation_number
if TYPE_CHECKING:
from typing import Any
from sphinx.application import Sphinx
from sphinx.builders.html import StandaloneHTMLBuilder
from sphinx.util.typing import ExtensionMetadata
from sphinx.writers.html5 import HTML5Translator
# more information for mathjax secure url is here:
# https://docs.mathjax.org/en/latest/web/start.html#using-mathjax-from-a-content-delivery-network-cdn
MATHJAX_URL = 'https://cdn.jsdelivr.net/npm/mathjax@4/tex-mml-chtml.js'
logger = sphinx.util.logging.getLogger(__name__)
def html_visit_math(self: HTML5Translator, node: nodes.math) -> None:
self.body.append(
self.starttag(node, 'span', '', CLASS='math notranslate nohighlight')
)
self.body.append(
self.builder.config.mathjax_inline[0]
+ self.encode(node.astext())
+ self.builder.config.mathjax_inline[1]
+ ''
)
raise nodes.SkipNode
def html_visit_displaymath(self: HTML5Translator, node: nodes.math_block) -> None:
self.body.append(self.starttag(node, 'div', CLASS='math notranslate nohighlight'))
if node.get('no-wrap', node.get('nowrap', False)):
self.body.append(self.encode(node.astext()))
self.body.append('')
raise nodes.SkipNode
# necessary to e.g. set the id property correctly
if node['number']:
number = get_node_equation_number(self, node)
self.body.append('(%s)' % number)
self.add_permalink_ref(node, _('Link to this equation'))
self.body.append('')
self.body.append(self.builder.config.mathjax_display[0])
parts = [prt for prt in node.astext().split('\n\n') if prt.strip()]
if len(parts) > 1: # Add alignment if there are more than 1 equation
self.body.append(r' \begin{align}\begin{aligned}')
for i, part in enumerate(parts):
part = self.encode(part)
if r'\\' in part:
self.body.append(r'\begin{split}' + part + r'\end{split}')
else:
self.body.append(part)
if i < len(parts) - 1: # append new line if not the last equation
self.body.append(r'\\')
if len(parts) > 1: # Add alignment if there are more than 1 equation
self.body.append(r'\end{aligned}\end{align} ')
self.body.append(self.builder.config.mathjax_display[1])
self.body.append('\n')
raise nodes.SkipNode
def install_mathjax(
app: Sphinx,
pagename: str,
templatename: str,
context: dict[str, Any],
event_arg: Any,
) -> None:
if app.builder.format != 'html':
return
if app.builder.math_renderer_name != 'mathjax': # type: ignore[attr-defined]
return
if not app.config.mathjax_path:
msg = 'mathjax_path config value must be set for the mathjax extension to work'
raise ExtensionError(msg)
builder = cast('StandaloneHTMLBuilder', app.builder)
page_has_equations = context.get('has_maths_elements', False)
# Enable mathjax only if equations exists
if app.registry.html_assets_policy == 'always' or page_has_equations:
if app.config.mathjax2_config:
if app.config.mathjax_path == MATHJAX_URL:
logger.warning(
'mathjax_config/mathjax2_config does not work '
'for the current MathJax version, use mathjax4_config instead'
)
body = f'MathJax.Hub.Config({json.dumps(app.config.mathjax2_config)})'
builder.add_js_file('', type='text/x-mathjax-config', body=body)
if app.config.mathjax3_config:
body = f'window.MathJax = {json.dumps(app.config.mathjax3_config)}'
builder.add_js_file('', body=body)
if app.config.mathjax4_config:
body = f'window.MathJax = {json.dumps(app.config.mathjax4_config)}'
builder.add_js_file('', body=body)
if app.config.mathjax_config_path:
config_path = app.confdir / app.config.mathjax_config_path
if not config_path.exists():
msg = f'mathjax_config_path file not found: {config_path}'
raise ExtensionError(msg)
if not config_path.is_file() or config_path.suffix != '.js':
msg = f'mathjax_config_path: expected a .js file, but got {config_path}'
raise ExtensionError(msg)
body = config_path.read_text(encoding='utf-8')
builder.add_js_file('', body=body)
options = {}
if app.config.mathjax_options:
options.update(app.config.mathjax_options)
if 'async' not in options and 'defer' not in options:
if app.config.mathjax2_config or app.config.mathjax_config:
# Load old MathJax versions via the 'async' method
options['async'] = 'async'
else:
# Load MathJax v3+ via the 'defer' method
options['defer'] = 'defer'
builder.add_js_file(app.config.mathjax_path, **options)
def setup(app: Sphinx) -> ExtensionMetadata:
app.add_html_math_renderer(
'mathjax',
inline_renderers=(html_visit_math, None),
block_renderers=(html_visit_displaymath, None),
)
app.add_config_value('mathjax_path', MATHJAX_URL, 'html', types=frozenset({str}))
app.add_config_value('mathjax_options', {}, 'html', types=frozenset({dict}))
app.add_config_value(
'mathjax_inline', [r'\(', r'\)'], 'html', types=frozenset({list, tuple})
)
app.add_config_value(
'mathjax_display', [r'\[', r'\]'], 'html', types=frozenset({list, tuple})
)
app.add_config_value(
'mathjax_config', None, 'html', types=frozenset({dict, NoneType})
)
app.add_config_value(
'mathjax2_config',
lambda c: c.mathjax_config,
'html',
types=frozenset({dict, NoneType}),
)
app.add_config_value(
'mathjax3_config', None, 'html', types=frozenset({dict, NoneType})
)
app.add_config_value(
'mathjax4_config', None, 'html', types=frozenset({dict, NoneType})
)
app.add_config_value('mathjax_config_path', '', 'html', types=frozenset({str}))
app.connect('html-page-context', install_mathjax)
return {
'version': sphinx.__display_version__,
'parallel_read_safe': True,
}