##// END OF EJS Templates
Use Draft4 JSON Schema for both v3 and v4...
Use Draft4 JSON Schema for both v3 and v4 no longer need jsonpointer

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markdown.py
226 lines | 6.7 KiB | text/x-python | PythonLexer
"""Markdown filters
This file contains a collection of utility filters for dealing with
markdown within Jinja templates.
"""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
from __future__ import print_function
# Stdlib imports
import os
import subprocess
from io import TextIOWrapper, BytesIO
import re
import mistune
from pygments import highlight
from pygments.lexers import get_lexer_by_name
from pygments.formatters import HtmlFormatter
from pygments.util import ClassNotFound
# IPython imports
from IPython.nbconvert.utils.pandoc import pandoc
from IPython.nbconvert.utils.exceptions import ConversionException
from IPython.utils.decorators import undoc
from IPython.utils.process import get_output_error_code
from IPython.utils.py3compat import cast_bytes
from IPython.utils.version import check_version
marked = os.path.join(os.path.dirname(__file__), "marked.js")
_node = None
__all__ = [
'markdown2html',
'markdown2html_pandoc',
'markdown2html_marked',
'markdown2html_mistune',
'markdown2latex',
'markdown2rst',
]
class NodeJSMissing(ConversionException):
"""Exception raised when node.js is missing."""
pass
def markdown2latex(source, extra_args=None):
"""Convert a markdown string to LaTeX via pandoc.
This function will raise an error if pandoc is not installed.
Any error messages generated by pandoc are printed to stderr.
Parameters
----------
source : string
Input string, assumed to be valid markdown.
Returns
-------
out : string
Output as returned by pandoc.
"""
return pandoc(source, 'markdown', 'latex', extra_args=extra_args)
@undoc
class MathBlockGrammar(mistune.BlockGrammar):
block_math = re.compile("^\$\$(.*?)\$\$", re.DOTALL)
latex_environment = re.compile(r"^\\begin\{([a-z]*\*?)\}(.*?)\\end\{\1\}",
re.DOTALL)
@undoc
class MathBlockLexer(mistune.BlockLexer):
default_features = ['block_math', 'latex_environment'] + mistune.BlockLexer.default_features
def __init__(self, rules=None, **kwargs):
if rules is None:
rules = MathBlockGrammar()
super(MathBlockLexer, self).__init__(rules, **kwargs)
def parse_block_math(self, m):
"""Parse a $$math$$ block"""
self.tokens.append({
'type': 'block_math',
'text': m.group(1)
})
def parse_latex_environment(self, m):
self.tokens.append({
'type': 'latex_environment',
'name': m.group(1),
'text': m.group(2)
})
@undoc
class MathInlineGrammar(mistune.InlineGrammar):
math = re.compile("^\$(.+?)\$")
@undoc
class MathInlineLexer(mistune.InlineLexer):
default_features = ['math'] + mistune.InlineLexer.default_features
def __init__(self, renderer, rules=None, **kwargs):
if rules is None:
rules = MathInlineGrammar()
super(MathInlineLexer, self).__init__(renderer, rules, **kwargs)
def output_math(self, m):
return self.renderer.inline_math(m.group(1))
@undoc
class MarkdownWithMath(mistune.Markdown):
def __init__(self, renderer, **kwargs):
if 'inline' not in kwargs:
kwargs['inline'] = MathInlineLexer
if 'block' not in kwargs:
kwargs['block'] = MathBlockLexer
super(MarkdownWithMath, self).__init__(renderer, **kwargs)
def parse_block_math(self):
return self.renderer.block_math(self.token['text'])
def parse_latex_environment(self):
return self.renderer.latex_environment(self.token['name'], self.token['text'])
@undoc
class IPythonRenderer(mistune.Renderer):
def block_code(self, code, lang):
if lang:
try:
lexer = get_lexer_by_name(lang, stripall=True)
except ClassNotFound:
code = lang + '\n' + code
lang = None
if not lang:
return '\n<pre><code>%s</code></pre>\n' % \
mistune.escape(code)
formatter = HtmlFormatter()
return highlight(code, lexer, formatter)
# Pass math through unaltered - mathjax does the rendering in the browser
def block_math(self, text):
return '$$%s$$' % text
def latex_environment(self, name, text):
return r'\begin{%s}%s\end{%s}' % (name, text, name)
def inline_math(self, text):
return '$%s$' % text
def markdown2html_mistune(source):
"""Convert a markdown string to HTML using mistune"""
return MarkdownWithMath(renderer=IPythonRenderer()).render(source)
def markdown2html_pandoc(source, extra_args=None):
"""Convert a markdown string to HTML via pandoc"""
extra_args = extra_args or ['--mathjax']
return pandoc(source, 'markdown', 'html', extra_args=extra_args)
def _find_nodejs():
global _node
if _node is None:
# prefer md2html via marked if node.js >= 0.9.12 is available
# node is called nodejs on debian, so try that first
_node = 'nodejs'
if not _verify_node(_node):
_node = 'node'
return _node
def markdown2html_marked(source, encoding='utf-8'):
"""Convert a markdown string to HTML via marked"""
command = [_find_nodejs(), marked]
try:
p = subprocess.Popen(command,
stdin=subprocess.PIPE, stdout=subprocess.PIPE
)
except OSError as e:
raise NodeJSMissing(
"The command '%s' returned an error: %s.\n" % (" ".join(command), e) +
"Please check that Node.js is installed."
)
out, _ = p.communicate(cast_bytes(source, encoding))
out = TextIOWrapper(BytesIO(out), encoding, 'replace').read()
return out.rstrip('\n')
# The mistune renderer is the default, because it's simple to depend on it
markdown2html = markdown2html_mistune
def markdown2rst(source, extra_args=None):
"""Convert a markdown string to ReST via pandoc.
This function will raise an error if pandoc is not installed.
Any error messages generated by pandoc are printed to stderr.
Parameters
----------
source : string
Input string, assumed to be valid markdown.
Returns
-------
out : string
Output as returned by pandoc.
"""
return pandoc(source, 'markdown', 'rst', extra_args=extra_args)
def _verify_node(cmd):
"""Verify that the node command exists and is at least the minimum supported
version of node.
Parameters
----------
cmd : string
Node command to verify (i.e 'node')."""
try:
out, err, return_code = get_output_error_code([cmd, '--version'])
except OSError:
# Command not found
return False
if return_code:
# Command error
return False
return check_version(out.lstrip('v'), '0.9.12')