159 lines
6.8 KiB
Python
159 lines
6.8 KiB
Python
|
# -*- 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')
|