markdown: use wikilink extension

For easier internal wiki links, activate the wikilink extension https://github.com/neurobin/mdx_wikilink_plus
Previously, an internal link had to be: `[OtherPage](OtherPage)`
now, this works too `[[OtherPage]]` and `[[Page/Subpage]]`

The wikilink extension of python-markdown itself (https://python-markdown.github.io/extensions/wikilinks/)
is very limited and does not handle links with slashes in their name, so
no sub pages

docs/user/markdown.rst

@@ -165,6 +165,22 @@ Inline links use the form: ::
 **reST NOTE**: Links with title attributes and images as links are not supported in reST.
 The internal links above are broken.
 
+Wikilinks
+---------
+
+Wikilinks use the form: ::
+
+    [[PageName]]
+
+===========================================   ===============================================
+ **Markup**                                    **Result**
+===========================================   ===============================================
+ [[Page]]                                      `Page <http:Page>`_
+ [[Page/Subpage]]                              `Subpage <http:Page/Subpage>`_
+===========================================   ===============================================
+
+This features uses the `mdx_wikilink_plus <https://github.com/neurobin/mdx_wikilink_plus>`_ extension.
+
 Reference Links
 ---------------
 

setup.py

@@ -75,6 +75,7 @@
         'blinker>=1.1',  # event signalling (e.g. for change notification trigger)
         'docutils>=0.18.1',  # reST markup processing
         'Markdown>=3.4.1',  # Markdown markup processing
+        'mdx_wikilink_plus' >= mdx_wikilink_plus, # Markdown Wikilinks extension
         'Flask<2.3.0',  # micro framework
         'Flask-Babel<3.0.0',  # i18n support
         'Flask-Caching>=1.2.0',  # caching support

src/moin/converters/_tests/test_markdown_in.py

@@ -134,6 +134,15 @@ def test_list(self, input, output):
     def test_image(self, input, output):
         self.do(input, output)
 
+    data = [('[[Bracketed]]',
+             '<p><a xlink:href="wiki.local:Bracketed">Bracketed</a></p>'),
+            ('[[Main/sub]]',  # check if label is kept lower case, check if slash in link is detected
+             '<p><a xlink:href="wiki.local:Main/sub">sub</a></p>')]
+    @pytest.mark.parametrize('input,output', data)
+    def test_wikilinks(self, input, output):
+        """ Test the Wikilinks extension: https://python-markdown.github.io/extensions/wikilinks/"""
+        self.do(input, output)
+
     def serialize_strip(self, elem, **options):
         result = serialize(elem, namespaces=self.namespaces, **options)
         return self.output_re.sub('', result)

src/moin/converters/markdown_in.py

@@ -28,6 +28,7 @@
 import markdown.util as md_util
 from markdown.extensions.extra import ExtraExtension
 from markdown.extensions.codehilite import CodeHiliteExtension
+from markdown.extensions.wikilinks import WikiLinkExtension
 
 from . import default_registry
 from moin.utils.mime import Type, type_moin_document
@@ -530,9 +531,18 @@ def convert_invalid_p_nodes(self, node):
 
     def __init__(self):
         self.markdown = Markdown(extensions=[
-            ExtraExtension(),
-            CodeHiliteExtension(guess_lang=False),
-        ])
+                ExtraExtension(),
+                CodeHiliteExtension(guess_lang=False),
+                'mdx_wikilink_plus',
+            ],
+            extension_configs={
+                'mdx_wikilink_plus': {
+                    'html_class': None,
+                    'image_class': None,
+                    'label_case': 'none',  # do not automatically CamelCase the label, keep it untouched
+                }
+            },
+        )
 
     @classmethod
     def _factory(cls, input, output, **kw):