TOC extension: Add new boolean option permalink_prepend (#1339)

Boolean flag which, when set to True, will cause permalink anchors
to be inserted at the start of heading elements, rather than at the
end (the default).

docs/change_log/index.md

@@ -3,12 +3,16 @@ title: Change Log
 Python-Markdown Change Log
 =========================
 
+
+*under development*: version 3.5 ([Notes](release-3.5.md))
+
 July 25, 2023: version 3.4.4 (a bug-fix release).
 
 * Add a special case for initial `'s` to smarty extension (#1305).
 * Unescape any backslash escaped inline raw HTML (#1358).
 * Unescape backslash escaped TOC token names (#1360).
 
+
 March 23, 2023: version 3.4.3 (a bug-fix release).
 
 * Restore console script (#1327).

docs/change_log/release-3.5.md

@@ -0,0 +1,20 @@
+title: Release Notes for v3.5
+
+# Python-Markdown 3.5 Release Notes
+
+Python-Markdown version 3.5 supports Python versions 3.7, 3.8, 3.9, 3.10,
+3.11 and PyPy3.
+
+## New features
+
+The following new features have been included in the 3.5 release:
+
+* A new configuration option has been added to the
+  [toc](../extensions/toc.md) extension (#1339):
+
+    * A new boolean option `permalink_leading` controls the position of
+      the permanent link anchors generated with `permalink`. Setting
+      `permalink_leading` to `True` will cause the links to be inserted
+      at the start of the header, before any other header content. The
+      default behavior for `permalink` is to append permanent links to
+      the header, placing them after all other header content.

docs/extensions/toc.md

@@ -174,6 +174,15 @@ The following options are provided to configure the output:
 * **`permalink_title`**:
     Title attribute of the permanent link. Defaults to `Permanent link`.
 
+* **`permalink_leading`**:
+    Set to `True` if the extension should generate leading permanent links.
+    Default is `False`.
+
+    Leading permanent links are placed at the start of the header tag,
+    before any header content. The default `permalink` behavior (when
+    `permalink_leading` is unset or set to `False`) creates trailing
+    permanent links, which are placed at the end of the header content.
+
 * **`baselevel`**:
     Base level for headers. Defaults to `1`.
 

markdown/extensions/toc.py

@@ -168,6 +168,7 @@ def __init__(self, md, config):
             self.use_permalinks = config["permalink"]
         self.permalink_class = config["permalink_class"]
         self.permalink_title = config["permalink_title"]
+        self.permalink_leading = parseBoolValue(config["permalink_leading"], False)
         self.header_rgx = re.compile("[Hh][123456]")
         if isinstance(config["toc_depth"], str) and '-' in config["toc_depth"]:
             self.toc_top, self.toc_bottom = [int(x) for x in config["toc_depth"].split('-')]
@@ -235,7 +236,12 @@ def add_permalink(self, c, elem_id):
         permalink.attrib["class"] = self.permalink_class
         if self.permalink_title:
             permalink.attrib["title"] = self.permalink_title
-        c.append(permalink)
+        if self.permalink_leading:
+            permalink.tail = c.text
+            c.text = ""
+            c.insert(0, permalink)
+        else:
+            c.append(permalink)
 
     def build_toc_div(self, toc_list):
         """ Return a string div given a toc list. """
@@ -347,6 +353,10 @@ def __init__(self, **kwargs):
             "permalink_title": ["Permanent link",
                                 "Title attribute of the permalink - "
                                 "Defaults to 'Permanent link'"],
+            "permalink_leading": [False,
+                                  "True if permalinks should be placed at "
+                                  "the start of the header, rather than the "
+                                  "end - Defaults to False."],
             "baselevel": ['1', 'Base level for headers.'],
             "slugify": [slugify,
                         "Function to generate anchors based on header text - "

mkdocs.yml

@@ -41,6 +41,7 @@ nav:
   - Test Tools: test_tools.md
   - Contributing to Python-Markdown: contributing.md
   - Change Log: change_log/index.md
+  - Release Notes for v.3.5: change_log/release-3.5.md
   - Release Notes for v.3.4: change_log/release-3.4.md
   - Release Notes for v.3.3: change_log/release-3.3.md
   - Release Notes for v.3.2: change_log/release-3.2.md

tests/test_extensions.py

@@ -629,3 +629,117 @@ def testTocInHeaders(self):
             '</div>\n'                                  # noqa
             '<h1 id="toc"><em>[TOC]</em></h1>'          # noqa
         )
+
+    def testPermalink(self):
+        """ Test TOC `permalink` feature. """
+        text = '# Hd 1\n\n## Hd 2'
+        md = markdown.Markdown(
+            extensions=[markdown.extensions.toc.TocExtension(
+                permalink=True, permalink_title="PL")]
+        )
+        self.assertEqual(
+            md.convert(text),
+            '<h1 id="hd-1">'
+                'Hd 1'                                            # noqa
+                '<a class="headerlink" href="#hd-1" title="PL">'  # noqa
+                    '&para;'                                      # noqa
+                '</a>'                                            # noqa
+            '</h1>\n'
+            '<h2 id="hd-2">'
+                'Hd 2'                                            # noqa
+                '<a class="headerlink" href="#hd-2" title="PL">'  # noqa
+                    '&para;'                                      # noqa
+                '</a>'                                            # noqa
+            '</h2>'
+        )
+
+    def testPermalinkLeading(self):
+        """ Test TOC `permalink` with `permalink_leading` option. """
+        text = '# Hd 1\n\n## Hd 2'
+        md = markdown.Markdown(extensions=[
+            markdown.extensions.toc.TocExtension(
+                permalink=True, permalink_title="PL", permalink_leading=True)]
+        )
+        self.assertEqual(
+            md.convert(text),
+            '<h1 id="hd-1">'
+                '<a class="headerlink" href="#hd-1" title="PL">'  # noqa
+                    '&para;'                                      # noqa
+                '</a>'                                            # noqa
+                'Hd 1'                                            # noqa
+            '</h1>\n'
+            '<h2 id="hd-2">'
+                '<a class="headerlink" href="#hd-2" title="PL">'  # noqa
+                    '&para;'                                      # noqa
+                '</a>'                                            # noqa
+                'Hd 2'                                            # noqa
+            '</h2>'
+        )
+
+    def testInlineMarkupPermalink(self):
+        """ Test TOC `permalink` with headers containing markup. """
+        text = '# Code `in` hd'
+        md = markdown.Markdown(
+            extensions=[markdown.extensions.toc.TocExtension(
+                permalink=True, permalink_title="PL")]
+        )
+        self.assertEqual(
+            md.convert(text),
+            '<h1 id="code-in-hd">'
+                'Code <code>in</code> hd'                               # noqa
+                '<a class="headerlink" href="#code-in-hd" title="PL">'  # noqa
+                    '&para;'                                            # noqa
+                '</a>'                                                  # noqa
+            '</h1>'
+        )
+
+    def testInlineMarkupPermalinkLeading(self):
+        """ Test TOC `permalink_leading` with headers containing markup. """
+        text = '# Code `in` hd'
+        md = markdown.Markdown(extensions=[
+            markdown.extensions.toc.TocExtension(
+                permalink=True, permalink_title="PL", permalink_leading=True)]
+        )
+        self.assertEqual(
+            md.convert(text),
+            '<h1 id="code-in-hd">'
+                '<a class="headerlink" href="#code-in-hd" title="PL">'  # noqa
+                    '&para;'                                            # noqa
+                '</a>'                                                  # noqa
+                'Code <code>in</code> hd'                               # noqa
+            '</h1>'
+        )
+
+
+class TestSmarty(unittest.TestCase):
+    def setUp(self):
+        config = {
+            'smarty': [
+                ('smart_angled_quotes', True),
+                ('substitutions', {
+                    'ndash': '\u2013',
+                    'mdash': '\u2014',
+                    'ellipsis': '\u2026',
+                    'left-single-quote': '&sbquo;',  # `sb` is not a typo!
+                    'right-single-quote': '&lsquo;',
+                    'left-double-quote': '&bdquo;',
+                    'right-double-quote': '&ldquo;',
+                    'left-angle-quote': '[',
+                    'right-angle-quote': ']',
+                }),
+            ]
+        }
+        self.md = markdown.Markdown(
+            extensions=['smarty'],
+            extension_configs=config
+        )
+
+    def testCustomSubstitutions(self):
+        text = """<< The "Unicode char of the year 2014"
+is the 'mdash': ---
+Must not be confused with 'ndash'  (--) ... >>
+"""
+        correct = """<p>[ The &bdquo;Unicode char of the year 2014&ldquo;
+is the &sbquo;mdash&lsquo;: \u2014
+Must not be confused with &sbquo;ndash&lsquo;  (\u2013) \u2026 ]</p>"""
+        self.assertEqual(self.md.convert(text), correct)