Varia's website, varia.zone or vvvvvvaria.org
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

158 lines
6.8 KiB

# -*- coding: utf-8 -*-
"""
Pelican Mathjax Markdown Extension
==================================
An extension for the Python Markdown module that enables
the Pelican python blog to process mathjax. This extension
gives Pelican the ability to use Mathjax as a "first class
citizen" of the blog
"""
import markdown
from markdown.util import etree
from markdown.util import AtomicString
class PelicanMathJaxPattern(markdown.inlinepatterns.Pattern):
"""Inline markdown processing that matches mathjax"""
def __init__(self, pelican_mathjax_extension, tag, pattern):
super(PelicanMathJaxPattern,self).__init__(pattern)
self.math_tag_class = pelican_mathjax_extension.getConfig('math_tag_class')
self.pelican_mathjax_extension = pelican_mathjax_extension
self.tag = tag
def handleMatch(self, m):
node = markdown.util.etree.Element(self.tag)
node.set('class', self.math_tag_class)
prefix = '\\(' if m.group('prefix') == '$' else m.group('prefix')
suffix = '\\)' if m.group('suffix') == '$' else m.group('suffix')
node.text = markdown.util.AtomicString(prefix + m.group('math') + suffix)
# If mathjax was successfully matched, then JavaScript needs to be added
# for rendering. The boolean below indicates this
self.pelican_mathjax_extension.mathjax_needed = True
return node
class PelicanMathJaxCorrectDisplayMath(markdown.treeprocessors.Treeprocessor):
"""Corrects invalid html that results from a <div> being put inside
a <p> for displayed math"""
def __init__(self, pelican_mathjax_extension):
self.pelican_mathjax_extension = pelican_mathjax_extension
def correct_html(self, root, children, div_math, insert_idx, text):
"""Separates out <div class="math"> from the parent tag <p>. Anything
in between is put into its own parent tag of <p>"""
current_idx = 0
for idx in div_math:
el = markdown.util.etree.Element('p')
el.text = text
el.extend(children[current_idx:idx])
# Test to ensure that empty <p> is not inserted
if len(el) != 0 or (el.text and not el.text.isspace()):
root.insert(insert_idx, el)
insert_idx += 1
text = children[idx].tail
children[idx].tail = None
root.insert(insert_idx, children[idx])
insert_idx += 1
current_idx = idx+1
el = markdown.util.etree.Element('p')
el.text = text
el.extend(children[current_idx:])
if len(el) != 0 or (el.text and not el.text.isspace()):
root.insert(insert_idx, el)
def run(self, root):
"""Searches for <div class="math"> that are children in <p> tags and corrects
the invalid HTML that results"""
math_tag_class = self.pelican_mathjax_extension.getConfig('math_tag_class')
for parent in root:
div_math = []
children = list(parent)
for div in parent.findall('div'):
if div.get('class') == math_tag_class:
div_math.append(children.index(div))
# Do not process further if no displayed math has been found
if not div_math:
continue
insert_idx = list(root).index(parent)
self.correct_html(root, children, div_math, insert_idx, parent.text)
root.remove(parent) # Parent must be removed last for correct insertion index
return root
class PelicanMathJaxAddJavaScript(markdown.treeprocessors.Treeprocessor):
"""Tree Processor for adding Mathjax JavaScript to the blog"""
def __init__(self, pelican_mathjax_extension):
self.pelican_mathjax_extension = pelican_mathjax_extension
def run(self, root):
# If no mathjax was present, then exit
if (not self.pelican_mathjax_extension.mathjax_needed):
return root
# Add the mathjax script to the html document
mathjax_script = etree.Element('script')
mathjax_script.set('type','text/javascript')
mathjax_script.text = AtomicString(self.pelican_mathjax_extension.getConfig('mathjax_script'))
root.append(mathjax_script)
# Reset the boolean switch to false so that script is only added
# to other pages if needed
self.pelican_mathjax_extension.mathjax_needed = False
return root
class PelicanMathJaxExtension(markdown.Extension):
"""A markdown extension enabling mathjax processing in Markdown for Pelican"""
def __init__(self, config):
try:
# Needed for markdown versions >= 2.5
self.config['mathjax_script'] = ['', 'Mathjax JavaScript script']
self.config['math_tag_class'] = ['math', 'The class of the tag in which mathematics is wrapped']
self.config['auto_insert'] = [True, 'Determines if mathjax script is automatically inserted into content']
super(PelicanMathJaxExtension,self).__init__(**config)
except AttributeError:
# Markdown versions < 2.5
config['mathjax_script'] = [config['mathjax_script'], 'Mathjax JavaScript script']
config['math_tag_class'] = [config['math_tag_class'], 'The class of the tag in which mathematic is wrapped']
config['auto_insert'] = [config['auto_insert'], 'Determines if mathjax script is automatically inserted into content']
super(PelicanMathJaxExtension,self).__init__(config)
# Used as a flag to determine if javascript
# needs to be injected into a document
self.mathjax_needed = False
def extendMarkdown(self, md, md_globals):
# Regex to detect mathjax
mathjax_inline_regex = r'(?P<prefix>\$)(?P<math>.+?)(?P<suffix>(?<!\s)\2)'
mathjax_display_regex = r'(?P<prefix>\$\$|\\begin\{(.+?)\})(?P<math>.+?)(?P<suffix>\2|\\end\{\3\})'
# Process mathjax before escapes are processed since escape processing will
# intefer with mathjax. The order in which the displayed and inlined math
# is registered below matters
md.inlinePatterns.add('mathjax_displayed', PelicanMathJaxPattern(self, 'div', mathjax_display_regex), '<escape')
md.inlinePatterns.add('mathjax_inlined', PelicanMathJaxPattern(self, 'span', mathjax_inline_regex), '<escape')
# Correct the invalid HTML that results from teh displayed math (<div> tag within a <p> tag)
md.treeprocessors.add('mathjax_correctdisplayedmath', PelicanMathJaxCorrectDisplayMath(self), '>inline')
# If necessary, add the JavaScript Mathjax library to the document. This must
# be last in the ordered dict (hence it is given the position '_end')
if self.getConfig('auto_insert'):
md.treeprocessors.add('mathjax_addjavascript', PelicanMathJaxAddJavaScript(self), '_end')