zulip/zerver/lib/markdown/include.py

57 lines
1.8 KiB
Python

import os
import re
from typing import List, Match
from xml.etree.ElementTree import Element
from markdown import Extension, Markdown
from markdown.blockparser import BlockParser
from markdown.blockprocessors import BlockProcessor
from zerver.lib.exceptions import InvalidMarkdownIncludeStatement
from zerver.lib.markdown.priorities import BLOCK_PROCESSOR_PRIORITIES
class IncludeExtension(Extension):
def __init__(self, base_path: str) -> None:
super().__init__()
self.base_path = base_path
def extendMarkdown(self, md: Markdown) -> None:
md.parser.blockprocessors.register(
IncludeBlockProcessor(md.parser, self.base_path),
"include",
BLOCK_PROCESSOR_PRIORITIES["include"],
)
class IncludeBlockProcessor(BlockProcessor):
RE = re.compile(r"^ {,3}\{!([^!]+)!\} *$", re.M)
def __init__(self, parser: BlockParser, base_path: str) -> None:
super().__init__(parser)
self.base_path = base_path
def test(self, parent: Element, block: str) -> bool:
return bool(self.RE.search(block))
def expand_include(self, m: Match[str]) -> str:
try:
with open(os.path.normpath(os.path.join(self.base_path, m[1]))) as f:
lines = f.read().splitlines()
except OSError as e:
raise InvalidMarkdownIncludeStatement(m[0].strip()) from e
for prep in self.parser.md.preprocessors:
lines = prep.run(lines)
return "\n".join(lines)
def run(self, parent: Element, blocks: List[str]) -> None:
self.parser.state.set("include")
self.parser.parseChunk(parent, self.RE.sub(self.expand_include, blocks.pop(0)))
self.parser.state.reset()
def makeExtension(base_path: str) -> IncludeExtension:
return IncludeExtension(base_path=base_path)