snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/lib/markdown/include.py

@@ -0,0 +1,60 @@
+import os
+import re
+from re import 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)