mirror of https://github.com/zulip/zulip.git
553 lines
18 KiB
Python
553 lines
18 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
|
|
from typing import Any, Callable, Dict, Iterable, List, Mapping, MutableSequence, Optional, Sequence
|
|
|
|
import lxml.html
|
|
from django.utils.html import escape
|
|
from markdown import Markdown
|
|
from markdown.extensions import Extension, codehilite
|
|
from markdown.extensions.codehilite import CodeHiliteExtension, parse_hl_lines
|
|
from markdown.preprocessors import Preprocessor
|
|
from pygments.lexers import get_lexer_by_name
|
|
from pygments.util import ClassNotFound
|
|
|
|
from zerver.lib.exceptions import MarkdownRenderingException
|
|
from zerver.lib.tex import render_tex
|
|
|
|
# Global vars
|
|
FENCE_RE = re.compile(
|
|
r"""
|
|
# ~~~ or ```
|
|
(?P<fence>
|
|
^(?:~{3,}|`{3,})
|
|
)
|
|
|
|
[ ]* # spaces
|
|
|
|
(?:
|
|
# language, like ".py" or "{javascript}"
|
|
\{?\.?
|
|
(?P<lang>
|
|
[a-zA-Z0-9_+-./#]+
|
|
) # "py" or "javascript"
|
|
|
|
[ ]* # spaces
|
|
|
|
# header for features that use fenced block header syntax (like spoilers)
|
|
(?P<header>
|
|
[^ ~`][^~`]*
|
|
)?
|
|
\}?
|
|
)?
|
|
$
|
|
""",
|
|
re.VERBOSE,
|
|
)
|
|
|
|
|
|
CODE_WRAP = "<pre><code{}>{}\n</code></pre>"
|
|
LANG_TAG = ' class="{}"'
|
|
|
|
|
|
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 [-](sS)?X "?(GET|DELETE|PATCH|POST)"?'
|
|
if line.startswith("curl"):
|
|
if re.search(regex, line) is None:
|
|
raise MarkdownRenderingException(error_msg.format(command=line.strip()))
|
|
|
|
|
|
CODE_VALIDATORS: Dict[Optional[str], Callable[[List[str]], None]] = {
|
|
"curl": validate_curl_content,
|
|
}
|
|
|
|
|
|
class FencedCodeExtension(Extension):
|
|
def __init__(self, config: Mapping[str, Any] = {}) -> None:
|
|
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) -> 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 ZulipBaseHandler:
|
|
def __init__(
|
|
self,
|
|
processor: "FencedBlockPreprocessor",
|
|
output: MutableSequence[str],
|
|
fence: Optional[str] = None,
|
|
process_contents: bool = False,
|
|
) -> None:
|
|
self.processor = processor
|
|
self.output = output
|
|
self.fence = fence
|
|
self.process_contents = process_contents
|
|
self.lines: List[str] = []
|
|
|
|
def handle_line(self, line: str) -> None:
|
|
if line.rstrip() == self.fence:
|
|
self.done()
|
|
else:
|
|
self.lines.append(line.rstrip())
|
|
|
|
def done(self) -> None:
|
|
if self.lines:
|
|
text = "\n".join(self.lines)
|
|
text = self.format_text(text)
|
|
|
|
# For code blocks, the contents should not receive further
|
|
# processing. Whereas with quote and spoiler blocks, we
|
|
# explicitly want Markdown formatting of the content
|
|
# inside. This behavior is controlled by the
|
|
# process_contents configuration flag.
|
|
if not self.process_contents:
|
|
text = self.processor.placeholder(text)
|
|
|
|
processed_lines = text.split("\n")
|
|
self.output.append("")
|
|
self.output.extend(processed_lines)
|
|
self.output.append("")
|
|
self.processor.pop()
|
|
|
|
def format_text(self, text: str) -> str:
|
|
"""Returns a formatted text.
|
|
Subclasses should override this method.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
|
|
def generic_handler(
|
|
processor: "FencedBlockPreprocessor",
|
|
output: MutableSequence[str],
|
|
fence: str,
|
|
lang: Optional[str],
|
|
header: Optional[str],
|
|
run_content_validators: bool = False,
|
|
default_language: Optional[str] = None,
|
|
) -> ZulipBaseHandler:
|
|
if lang is not None:
|
|
lang = lang.lower()
|
|
if lang in ("quote", "quoted"):
|
|
return QuoteHandler(processor, output, fence, default_language)
|
|
elif lang == "math":
|
|
return TexHandler(processor, output, fence)
|
|
elif lang == "spoiler":
|
|
return SpoilerHandler(processor, output, fence, header)
|
|
else:
|
|
return CodeHandler(processor, output, fence, lang, run_content_validators)
|
|
|
|
|
|
def check_for_new_fence(
|
|
processor: "FencedBlockPreprocessor",
|
|
output: MutableSequence[str],
|
|
line: str,
|
|
run_content_validators: bool = False,
|
|
default_language: Optional[str] = None,
|
|
) -> None:
|
|
m = FENCE_RE.match(line)
|
|
if m:
|
|
fence = m.group("fence")
|
|
lang: Optional[str] = m.group("lang")
|
|
header: Optional[str] = m.group("header")
|
|
if not lang and default_language:
|
|
lang = default_language
|
|
handler = generic_handler(
|
|
processor, output, fence, lang, header, run_content_validators, default_language
|
|
)
|
|
processor.push(handler)
|
|
else:
|
|
output.append(line)
|
|
|
|
|
|
class OuterHandler(ZulipBaseHandler):
|
|
def __init__(
|
|
self,
|
|
processor: "FencedBlockPreprocessor",
|
|
output: MutableSequence[str],
|
|
run_content_validators: bool = False,
|
|
default_language: Optional[str] = None,
|
|
) -> None:
|
|
self.run_content_validators = run_content_validators
|
|
self.default_language = default_language
|
|
super().__init__(processor, output)
|
|
|
|
def handle_line(self, line: str) -> None:
|
|
check_for_new_fence(
|
|
self.processor, self.output, line, self.run_content_validators, self.default_language
|
|
)
|
|
|
|
|
|
class CodeHandler(ZulipBaseHandler):
|
|
def __init__(
|
|
self,
|
|
processor: "FencedBlockPreprocessor",
|
|
output: MutableSequence[str],
|
|
fence: str,
|
|
lang: Optional[str],
|
|
run_content_validators: bool = False,
|
|
) -> None:
|
|
self.lang = lang
|
|
self.run_content_validators = run_content_validators
|
|
super().__init__(processor, output, fence)
|
|
|
|
def done(self) -> None:
|
|
# run content validators (if any)
|
|
if self.run_content_validators:
|
|
validator = CODE_VALIDATORS.get(self.lang, lambda text: None)
|
|
validator(self.lines)
|
|
super().done()
|
|
|
|
def format_text(self, text: str) -> str:
|
|
return self.processor.format_code(self.lang, text)
|
|
|
|
|
|
class QuoteHandler(ZulipBaseHandler):
|
|
def __init__(
|
|
self,
|
|
processor: "FencedBlockPreprocessor",
|
|
output: MutableSequence[str],
|
|
fence: str,
|
|
default_language: Optional[str] = None,
|
|
) -> None:
|
|
self.default_language = default_language
|
|
super().__init__(processor, output, fence, process_contents=True)
|
|
|
|
def handle_line(self, line: str) -> None:
|
|
if line.rstrip() == self.fence:
|
|
self.done()
|
|
else:
|
|
check_for_new_fence(
|
|
self.processor, self.lines, line, default_language=self.default_language
|
|
)
|
|
|
|
def format_text(self, text: str) -> str:
|
|
return self.processor.format_quote(text)
|
|
|
|
|
|
class SpoilerHandler(ZulipBaseHandler):
|
|
def __init__(
|
|
self,
|
|
processor: "FencedBlockPreprocessor",
|
|
output: MutableSequence[str],
|
|
fence: str,
|
|
spoiler_header: Optional[str],
|
|
) -> None:
|
|
self.spoiler_header = spoiler_header
|
|
super().__init__(processor, output, fence, process_contents=True)
|
|
|
|
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 format_text(self, text: str) -> str:
|
|
return self.processor.format_spoiler(self.spoiler_header, text)
|
|
|
|
|
|
class TexHandler(ZulipBaseHandler):
|
|
def format_text(self, text: str) -> str:
|
|
return self.processor.format_tex(text)
|
|
|
|
|
|
class CodeHilite(codehilite.CodeHilite):
|
|
def _parseHeader(self) -> None:
|
|
# Python-Markdown has a feature to parse-and-hide shebang
|
|
# lines present in code blocks:
|
|
#
|
|
# https://python-markdown.github.io/extensions/code_hilite/#shebang-no-path
|
|
#
|
|
# While using shebang lines for language detection is
|
|
# reasonable, we don't want this feature because it can be
|
|
# really confusing when doing anything else in a one-line code
|
|
# block that starts with `!` (which would then render as an
|
|
# empty code block!). So we disable the feature, by
|
|
# overriding this function, which implements it in CodeHilite
|
|
# upstream.
|
|
|
|
# split text into lines
|
|
lines = self.src.split("\n")
|
|
# Python-Markdown pops out the first line which we are avoiding here.
|
|
# Examine first line
|
|
fl = lines[0]
|
|
|
|
c = re.compile(
|
|
r"""
|
|
(?:(?:^::+)|(?P<shebang>^[#]!)) # Shebang or 2 or more colons
|
|
(?P<path>(?:/\w+)*[/ ])? # Zero or 1 path
|
|
(?P<lang>[\w#.+-]*) # The language
|
|
\s* # Arbitrary whitespace
|
|
# Optional highlight lines, single- or double-quote-delimited
|
|
(hl_lines=(?P<quot>"|')(?P<hl_lines>.*?)(?P=quot))?
|
|
""",
|
|
re.VERBOSE,
|
|
)
|
|
# Search first line for shebang
|
|
m = c.search(fl)
|
|
if m:
|
|
# We have a match
|
|
try:
|
|
self.lang = m.group("lang").lower()
|
|
except IndexError: # nocoverage
|
|
self.lang = None
|
|
|
|
if self.options["linenos"] is None and m.group("shebang"):
|
|
# Overridable and Shebang exists - use line numbers
|
|
self.options["linenos"] = True
|
|
|
|
self.options["hl_lines"] = parse_hl_lines(m.group("hl_lines"))
|
|
|
|
self.src = "\n".join(lines).strip("\n")
|
|
|
|
|
|
class FencedBlockPreprocessor(Preprocessor):
|
|
def __init__(self, md: Markdown, run_content_validators: bool = False) -> None:
|
|
super().__init__(md)
|
|
|
|
self.checked_for_codehilite = False
|
|
self.run_content_validators = run_content_validators
|
|
self.codehilite_conf: Mapping[str, Sequence[Any]] = {}
|
|
|
|
def push(self, handler: ZulipBaseHandler) -> 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: List[str] = []
|
|
|
|
processor = self
|
|
self.handlers: List[ZulipBaseHandler] = []
|
|
|
|
default_language = None
|
|
try:
|
|
default_language = self.md.zulip_realm.default_code_block_language
|
|
except AttributeError:
|
|
pass
|
|
handler = OuterHandler(processor, output, self.run_content_validators, default_language)
|
|
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. Markdown 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: Optional[str], text: str) -> str:
|
|
if lang:
|
|
langclass = LANG_TAG.format(lang)
|
|
else:
|
|
langclass = ""
|
|
|
|
# Check for code hilite extension
|
|
if not self.checked_for_codehilite:
|
|
for ext in self.md.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().rstrip("\n")
|
|
else:
|
|
code = CODE_WRAP.format(langclass, self._escape(text))
|
|
|
|
# To support our "view in playground" feature, the frontend
|
|
# needs to know what Pygments language was used for
|
|
# highlighting this code block. We record this in a data
|
|
# attribute attached to the outer `pre` element.
|
|
# Unfortunately, the pygments API doesn't offer a way to add
|
|
# this, so we need to do it in a post-processing step.
|
|
if lang:
|
|
div_tag = lxml.html.fromstring(code)
|
|
|
|
# For the value of our data element, we get the lexer
|
|
# subclass name instead of directly using the language,
|
|
# since that canonicalizes aliases (Eg: `js` and
|
|
# `javascript` will be mapped to `JavaScript`).
|
|
try:
|
|
code_language = get_lexer_by_name(lang).name
|
|
except ClassNotFound:
|
|
# If there isn't a Pygments lexer by this name, we
|
|
# still tag it with the user's data-code-language
|
|
# value, since this allows hooking up a "playground"
|
|
# for custom "languages" that aren't known to Pygments.
|
|
code_language = lang
|
|
|
|
div_tag.attrib["data-code-language"] = code_language
|
|
code = lxml.html.tostring(div_tag, encoding="unicode")
|
|
return code
|
|
|
|
def format_quote(self, text: str) -> str:
|
|
paragraphs = text.split("\n")
|
|
quoted_paragraphs = []
|
|
for paragraph in paragraphs:
|
|
lines = paragraph.split("\n")
|
|
quoted_paragraphs.append("\n".join("> " + line for line in lines))
|
|
return "\n".join(quoted_paragraphs)
|
|
|
|
def format_spoiler(self, header: Optional[str], text: str) -> str:
|
|
output = []
|
|
header_div_open_html = '<div class="spoiler-block"><div class="spoiler-header">'
|
|
end_header_start_content_html = '</div><div class="spoiler-content" aria-hidden="true">'
|
|
footer_html = "</div></div>"
|
|
|
|
output.append(self.placeholder(header_div_open_html))
|
|
if header is not None:
|
|
output.append(header)
|
|
output.append(self.placeholder(end_header_start_content_html))
|
|
output.append(text)
|
|
output.append(self.placeholder(footer_html))
|
|
return "\n\n".join(output)
|
|
|
|
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.md.htmlStash.store(code)
|
|
|
|
def _escape(self, txt: str) -> str:
|
|
"""basic html escaping"""
|
|
txt = txt.replace("&", "&")
|
|
txt = txt.replace("<", "<")
|
|
txt = txt.replace(">", ">")
|
|
txt = txt.replace('"', """)
|
|
return txt
|
|
|
|
|
|
def makeExtension(*args: Any, **kwargs: None) -> FencedCodeExtension:
|
|
return FencedCodeExtension(kwargs)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod()
|