From 1a1aad9cc9ad5e155d7565db7d83aa4c1eb92454 Mon Sep 17 00:00:00 2001
From: Sebastian Wagner <sebix@sebix.at>
Date: Fri, 25 Jul 2025 18:31:24 +0200
Subject: [PATCH] Configuration option for markdown extensions

Introduces a new optional configuration parameter to specify any
instance-specific extensions for the markdown parser

based on https://github.com/moinwiki/moin/pull/1964

implements https://github.com/moinwiki/moin/issues/1957
---
 docs/user/markdown.rst                            | 12 ++++++++++++
 src/moin/config/default.py                        |  1 +
 src/moin/converters/_tests/test_markdown_in.py    | 15 ++++++++++++++-
 .../converters/_tests/test_markdown_in_out.py     | 15 ++++++++++++++-
 src/moin/converters/markdown_in.py                |  7 ++++++-
 5 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/docs/user/markdown.rst b/docs/user/markdown.rst
index 48703426b..038e1a9d8 100644
--- a/docs/user/markdown.rst
+++ b/docs/user/markdown.rst
@@ -753,3 +753,15 @@ The following types are supported:
 
 .. note::
    You should note that the title will be automatically capitalized.
+
+Instance-specific extensions
+----------------------------
+
+You can specify a list of additional extensions to the markdown parser per instance.
+A list of potentially interesting extensions can be access in `Python-markdown's wiki <https://github.com/Python-Markdown/markdown/wiki/Third-Party-Extensions>`_.
+
+For example, to automatically link URLs: ::
+
+    class Config(DefaultConfig):
+        ...
+        markdown_extensions = ['pymdownx.magiclink']
diff --git a/src/moin/config/default.py b/src/moin/config/default.py
index 1c469c5a8..79f88b8fb 100644
--- a/src/moin/config/default.py
+++ b/src/moin/config/default.py
@@ -54,6 +54,7 @@ class for the benefit of the WikiConfig macro.
     auth_have_login = None
     auth_login_inputs = None
     _site_plugin_lists = None
+    markdown_extensions = []
 
     def __init__(self):
         """Init Config instance"""
diff --git a/src/moin/converters/_tests/test_markdown_in.py b/src/moin/converters/_tests/test_markdown_in.py
index 033b20d87..af7d5166c 100644
--- a/src/moin/converters/_tests/test_markdown_in.py
+++ b/src/moin/converters/_tests/test_markdown_in.py
@@ -6,7 +6,9 @@
 MoinMoin - Tests for moin.converters.markdown_in
 """
 
+from collections import namedtuple
 import pytest
+from flask import Flask
 
 from . import serialize, XMLNS_RE
 
@@ -15,13 +17,24 @@
 from ..markdown_in import Converter
 
 
+DefaultConfig = namedtuple("DefaultConfig", ("markdown_extensions",))
+config = DefaultConfig(markdown_extensions=[])
+
+
 class TestConverter:
     namespaces = {moin_page: "", xlink: "xlink", xinclude: "xinclude", html: "html"}
 
     output_re = XMLNS_RE
 
     def setup_class(self):
-        self.conv = Converter()
+        # mock patching flask.current_app.cfg does not work here as for speccing the original object is called and that causes a "RuntimeError: working outside of application context"
+        app = Flask(__name__)
+        # DefaultConfig doesn't work here as it does not provide all the defaults required to be initialized
+        app.cfg = config
+        ctx = app.app_context()
+        ctx.push()
+        with ctx:
+            self.conv = Converter()
 
     data = [
         ("Text", "<p>Text</p>"),
diff --git a/src/moin/converters/_tests/test_markdown_in_out.py b/src/moin/converters/_tests/test_markdown_in_out.py
index 36ac80b48..e46f35d75 100644
--- a/src/moin/converters/_tests/test_markdown_in_out.py
+++ b/src/moin/converters/_tests/test_markdown_in_out.py
@@ -7,7 +7,9 @@
 MoinMoin - Tests for markdown->DOM->markdown using markdown_in and markdown_out converters
 """
 
+from collections import namedtuple
 import pytest
+from flask import Flask
 
 from emeraldtree import ElementTree as ET
 
@@ -18,6 +20,10 @@
 from moin.converters.markdown_out import Converter as conv_out
 
 
+DefaultConfig = namedtuple("DefaultConfig", ("markdown_extensions",))
+config = DefaultConfig(markdown_extensions=[])
+
+
 class TestConverter:
 
     input_namespaces = 'xmlns="{}" xmlns:page="{}" xmlns:xlink="{}" xmlns:xinclude="{}" xmlns:html="{}"'.format(
@@ -36,7 +42,14 @@ class TestConverter:
     output_re = XMLNS_RE
 
     def setup_class(self):
-        self.conv_in = conv_in()
+        # mock patching flask.current_app.cfg does not work here as for speccing the original object is called and that causes a "RuntimeError: working outside of application context"
+        app = Flask(__name__)
+        # DefaultConfig doesn't work here as it does not provide all the defaults required to be initialized
+        app.cfg = config
+        ctx = app.app_context()
+        ctx.push()
+        with ctx:
+            self.conv_in = conv_in()
         self.conv_out = conv_out()
 
     data = [
diff --git a/src/moin/converters/markdown_in.py b/src/moin/converters/markdown_in.py
index 2d83dcef3..b2f6753f1 100644
--- a/src/moin/converters/markdown_in.py
+++ b/src/moin/converters/markdown_in.py
@@ -17,6 +17,7 @@
 from ._util import decode_data
 from moin.utils.iri import Iri
 from moin.converters.html_in import Converter as HTML_IN_Converter
+from flask import current_app
 
 from emeraldtree import ElementTree as ET
 
@@ -558,8 +559,12 @@ def convert_invalid_p_nodes(self, node):
                 self.convert_invalid_p_nodes(child)
 
     def __init__(self):
+        # The Moin configuration
+        self.app_configuration = current_app.cfg
+
         self.markdown = Markdown(
-            extensions=[ExtraExtension(), CodeHiliteExtension(guess_lang=False), "mdx_wikilink_plus", "admonition"],
+            extensions=[ExtraExtension(), CodeHiliteExtension(guess_lang=False), "mdx_wikilink_plus", "admonition"]
+            + self.app_configuration.markdown_extensions,
             extension_configs={
                 "mdx_wikilink_plus": {
                     "html_class": None,