zulip/zerver/lib/bugdown/fenced_code.py

381 lines
12 KiB
Python

"""
Fenced Code Extension for Python Markdown
=========================================
This extension adds Fenced Code Blocks to Python-Markdown.
>>> import markdown
>>> text = '''
... A paragraph before a fenced code block:
...
... ~~~
... Fenced code block
... ~~~
... '''
>>> html = markdown.markdown(text, extensions=['fenced_code'])
>>> print html
<p>A paragraph before a fenced code block:</p>
<pre><code>Fenced code block
</code></pre>
Works with safe_mode also (we check this because we are using the HtmlStash):
>>> print markdown.markdown(text, extensions=['fenced_code'], safe_mode='replace')
<p>A paragraph before a fenced code block:</p>
<pre><code>Fenced code block
</code></pre>
Include tilde's in a code block and wrap with blank lines:
>>> text = '''
... ~~~~~~~~
...
... ~~~~
... ~~~~~~~~'''
>>> print markdown.markdown(text, extensions=['fenced_code'])
<pre><code>
~~~~
</code></pre>
Removes trailing whitespace from code blocks that cause horizontal scrolling
>>> import markdown
>>> text = '''
... A paragraph before a fenced code block:
...
... ~~~
... Fenced code block \t\t\t\t\t\t\t
... ~~~
... '''
>>> html = markdown.markdown(text, extensions=['fenced_code'])
>>> print html
<p>A paragraph before a fenced code block:</p>
<pre><code>Fenced code block
</code></pre>
Language tags:
>>> text = '''
... ~~~~{.python}
... # Some python code
... ~~~~'''
>>> print markdown.markdown(text, extensions=['fenced_code'])
<pre><code class="python"># Some python code
</code></pre>
Copyright 2007-2008 [Waylan Limberg](http://achinghead.com/).
Project website: <http://packages.python.org/Markdown/extensions/fenced_code_blocks.html>
Contact: markdown@freewisdom.org
License: BSD (see ../docs/LICENSE for details)
Dependencies:
* [Python 2.4+](http://python.org)
* [Markdown 2.0+](http://packages.python.org/Markdown/)
* [Pygments (optional)](http://pygments.org)
"""
import re
import markdown
from django.utils.html import escape
from markdown.extensions.codehilite import CodeHilite, CodeHiliteExtension
from zerver.lib.exceptions import BugdownRenderingException
from zerver.lib.tex import render_tex
from typing import Any, Dict, Iterable, List, MutableSequence, Optional
# Global vars
FENCE_RE = re.compile("""
# ~~~ or ```
(?P<fence>
^(?:~{3,}|`{3,})
)
[ ]* # spaces
(
\\{?\\.?
(?P<lang>
[a-zA-Z0-9_+-./#]*
) # "py" or "javascript"
\\}?
) # language, like ".py" or "{javascript}"
[ ]* # spaces
$
""", re.VERBOSE)
CODE_WRAP = '<pre><code%s>%s\n</code></pre>'
LANG_TAG = ' class="%s"'
def validate_curl_content(lines: List[str]) -> None:
error_msg = """
Missing required -X argument in curl command:
{command}
""".strip()
for line in lines:
regex = r'curl [-]X "?(GET|DELETE|PATCH|POST)"?'
if line.startswith('curl'):
if re.search(regex, line) is None:
raise BugdownRenderingException(error_msg.format(command=line.strip()))
CODE_VALIDATORS = {
'curl': validate_curl_content,
}
class FencedCodeExtension(markdown.Extension):
def __init__(self, config: Optional[Dict[str, Any]]=None) -> None:
if config is None:
config = {}
self.config = {
'run_content_validators': [
config.get('run_content_validators', False),
'Boolean specifying whether to run content validation code in CodeHandler'
]
}
for key, value in config.items():
self.setConfig(key, value)
def extendMarkdown(self, md: markdown.Markdown, md_globals: Dict[str, Any]) -> None:
""" Add FencedBlockPreprocessor to the Markdown instance. """
md.registerExtension(self)
processor = FencedBlockPreprocessor(
md, run_content_validators=self.config['run_content_validators'][0])
md.preprocessors.register(processor, 'fenced_code_block', 25)
class BaseHandler:
def handle_line(self, line: str) -> None:
raise NotImplementedError()
def done(self) -> None:
raise NotImplementedError()
def generic_handler(processor: Any, output: MutableSequence[str],
fence: str, lang: str,
run_content_validators: Optional[bool]=False) -> BaseHandler:
if lang in ('quote', 'quoted'):
return QuoteHandler(processor, output, fence)
elif lang in ('math', 'tex', 'latex'):
return TexHandler(processor, output, fence)
else:
return CodeHandler(processor, output, fence, lang, run_content_validators)
def check_for_new_fence(processor: Any, output: MutableSequence[str], line: str,
run_content_validators: Optional[bool]=False) -> None:
m = FENCE_RE.match(line)
if m:
fence = m.group('fence')
lang = m.group('lang')
handler = generic_handler(processor, output, fence, lang, run_content_validators)
processor.push(handler)
else:
output.append(line)
class OuterHandler(BaseHandler):
def __init__(self, processor: Any, output: MutableSequence[str],
run_content_validators: Optional[bool]=False) -> None:
self.output = output
self.processor = processor
self.run_content_validators = run_content_validators
def handle_line(self, line: str) -> None:
check_for_new_fence(self.processor, self.output, line,
self.run_content_validators)
def done(self) -> None:
self.processor.pop()
class CodeHandler(BaseHandler):
def __init__(self, processor: Any, output: MutableSequence[str],
fence: str, lang: str, run_content_validators: Optional[bool]=False) -> None:
self.processor = processor
self.output = output
self.fence = fence
self.lang = lang
self.lines = [] # type: List[str]
self.run_content_validators = run_content_validators
def handle_line(self, line: str) -> None:
if line.rstrip() == self.fence:
self.done()
else:
self.lines.append(line.rstrip())
def done(self) -> None:
text = '\n'.join(self.lines)
# run content validators (if any)
if self.run_content_validators:
validator = CODE_VALIDATORS.get(self.lang, lambda text: None)
validator(self.lines)
text = self.processor.format_code(self.lang, text)
text = self.processor.placeholder(text)
processed_lines = text.split('\n')
self.output.append('')
self.output.extend(processed_lines)
self.output.append('')
self.processor.pop()
class QuoteHandler(BaseHandler):
def __init__(self, processor: Any, output: MutableSequence[str], fence: str) -> None:
self.processor = processor
self.output = output
self.fence = fence
self.lines = [] # type: List[str]
def handle_line(self, line: str) -> None:
if line.rstrip() == self.fence:
self.done()
else:
check_for_new_fence(self.processor, self.lines, line)
def done(self) -> None:
text = '\n'.join(self.lines)
text = self.processor.format_quote(text)
processed_lines = text.split('\n')
self.output.append('')
self.output.extend(processed_lines)
self.output.append('')
self.processor.pop()
class TexHandler(BaseHandler):
def __init__(self, processor: Any, output: MutableSequence[str], fence: str) -> None:
self.processor = processor
self.output = output
self.fence = fence
self.lines = [] # type: List[str]
def handle_line(self, line: str) -> None:
if line.rstrip() == self.fence:
self.done()
else:
self.lines.append(line)
def done(self) -> None:
text = '\n'.join(self.lines)
text = self.processor.format_tex(text)
text = self.processor.placeholder(text)
processed_lines = text.split('\n')
self.output.append('')
self.output.extend(processed_lines)
self.output.append('')
self.processor.pop()
class FencedBlockPreprocessor(markdown.preprocessors.Preprocessor):
def __init__(self, md: markdown.Markdown, run_content_validators: Optional[bool]=False) -> None:
markdown.preprocessors.Preprocessor.__init__(self, md)
self.checked_for_codehilite = False
self.run_content_validators = run_content_validators
self.codehilite_conf = {} # type: Dict[str, List[Any]]
def push(self, handler: BaseHandler) -> None:
self.handlers.append(handler)
def pop(self) -> None:
self.handlers.pop()
def run(self, lines: Iterable[str]) -> List[str]:
""" Match and store Fenced Code Blocks in the HtmlStash. """
output = [] # type: List[str]
processor = self
self.handlers = [] # type: List[BaseHandler]
handler = OuterHandler(processor, output, self.run_content_validators)
self.push(handler)
for line in lines:
self.handlers[-1].handle_line(line)
while self.handlers:
self.handlers[-1].done()
# This fiddly handling of new lines at the end of our output was done to make
# existing tests pass. Bugdown is just kind of funny when it comes to new lines,
# but we could probably remove this hack.
if len(output) > 2 and output[-2] != '':
output.append('')
return output
def format_code(self, lang: str, text: str) -> str:
if lang:
langclass = LANG_TAG % (lang,)
else:
langclass = ''
# Check for code hilite extension
if not self.checked_for_codehilite:
for ext in self.markdown.registeredExtensions:
if isinstance(ext, CodeHiliteExtension):
self.codehilite_conf = ext.config
break
self.checked_for_codehilite = True
# If config is not empty, then the codehighlite extension
# is enabled, so we call it to highlite the code
if self.codehilite_conf:
highliter = CodeHilite(text,
linenums=self.codehilite_conf['linenums'][0],
guess_lang=self.codehilite_conf['guess_lang'][0],
css_class=self.codehilite_conf['css_class'][0],
style=self.codehilite_conf['pygments_style'][0],
use_pygments=self.codehilite_conf['use_pygments'][0],
lang=(lang or None),
noclasses=self.codehilite_conf['noclasses'][0])
code = highliter.hilite()
else:
code = CODE_WRAP % (langclass, self._escape(text))
return code
def format_quote(self, text: str) -> str:
paragraphs = text.split("\n\n")
quoted_paragraphs = []
for paragraph in paragraphs:
lines = paragraph.split("\n")
quoted_paragraphs.append("\n".join("> " + line for line in lines if line != ''))
return "\n\n".join(quoted_paragraphs)
def format_tex(self, text: str) -> str:
paragraphs = text.split("\n\n")
tex_paragraphs = []
for paragraph in paragraphs:
html = render_tex(paragraph, is_inline=False)
if html is not None:
tex_paragraphs.append(html)
else:
tex_paragraphs.append('<span class="tex-error">' +
escape(paragraph) + '</span>')
return "\n\n".join(tex_paragraphs)
def placeholder(self, code: str) -> str:
return self.markdown.htmlStash.store(code)
def _escape(self, txt: str) -> str:
""" basic html escaping """
txt = txt.replace('&', '&amp;')
txt = txt.replace('<', '&lt;')
txt = txt.replace('>', '&gt;')
txt = txt.replace('"', '&quot;')
return txt
def makeExtension(*args: Any, **kwargs: None) -> FencedCodeExtension:
return FencedCodeExtension(kwargs)
if __name__ == "__main__":
import doctest
doctest.testmod()