src/librarian/embeds/mathml.py

   1 # -*- coding: utf-8 -*-
   2 from __future__ import unicode_literals
   3
   4 from lxml import etree
   5 import six
   6 from librarian import get_resource
   7 from . import TreeEmbed, create_embed, downgrades_to
   8
   9
  10 class MathML(TreeEmbed):
  11     @downgrades_to('application/x-latex')
  12     def to_latex(self):
  13         """
  14         >>> print(MathML(etree.fromstring(
  15                 '<mat>a &lt; b</mat>'
  16             )).to_latex().data.strip())
  17         a < b
  18
  19         >>> print(MathML(etree.fromstring(
  20                 '<mat>&lt; &amp; &amp;lt; &#65;</mat>'
  21             )).to_latex().data.strip())
  22         < & &lt; A
  23
  24         """
  25         xslt = etree.parse(get_resource('res/embeds/mathml/mathml2latex.xslt'))
  26         output = self.tree.xslt(xslt)
  27         text = six.text_type(output)
  28         # Workaround for entities being preserved in output.
  29         # But there should be a better way.
  30         text = text.replace('&lt;', '<').replace('&amp;', '&')
  31         return create_embed('application/x-latex', data=text)