zulip/zerver/lib/markdown/include.py

61 lines
1.9 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 typing_extensions import override
from zerver.lib.exceptions import InvalidMarkdownIncludeStatementError
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
@override
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.MULTILINE)
def __init__(self, parser: BlockParser, base_path: str) -> None:
super().__init__(parser)
self.base_path = base_path
@override
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 InvalidMarkdownIncludeStatementError(m[0].strip()) from e
for prep in self.parser.md.preprocessors:
lines = prep.run(lines)
return "\n".join(lines)
@override
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)