normalize tag

Author: tylerdave

src/rockgarden/output/tags.py

@@ -1,28 +1,11 @@
 """Tag index page generation."""
 
-import re
 from pathlib import Path
 
 from jinja2 import Environment
 
 from rockgarden.content.models import Page
-from rockgarden.urls import get_tag_url, get_tags_root_url, get_url
-
-
-def normalize_tag(tag: str) -> str:
-    """Normalize a tag to a URL-safe slug.
-
-    Strips leading '#', lowercases, and replaces any character that is not
-    alphanumeric, hyphen, or underscore with a hyphen. This prevents path
-    traversal via tags containing '/' or '..'.
-
-    Tags 'Python', '#python', and 'python' all normalize to 'python'.
-    Obsidian nested tags like 'character/pc' normalize to 'character-pc'.
-    """
-    slug = tag.lstrip("#").lower()
-    slug = re.sub(r"[^a-z0-9_-]", "-", slug)
-    slug = re.sub(r"-+", "-", slug)
-    return slug.strip("-")
+from rockgarden.urls import get_tag_url, get_tags_root_url, get_url, normalize_tag
 
 
 def collect_tags(pages: list[Page]) -> dict[str, list[Page]]:

src/rockgarden/render/engine.py

@@ -10,7 +10,7 @@
 from rockgarden.config import Config
 from rockgarden.content.models import Page
 from rockgarden.nav.tree import NavNode
-from rockgarden.urls import get_tag_url, get_tags_root_url
+from rockgarden.urls import get_tag_url, get_tags_root_url, normalize_tag
 
 
 def _make_format_datetime(tz_name: str):
@@ -64,6 +64,7 @@ def create_engine(
     )
     env.filters["format_datetime"] = _make_format_datetime(config.dates.timezone)
     clean_urls = config.site.clean_urls
+    env.globals["normalize_tag"] = normalize_tag
     env.globals["tag_url"] = lambda slug: get_tag_url(slug, clean_urls)
     env.globals["tags_root_url"] = get_tags_root_url(clean_urls)
     return env

src/rockgarden/templates/folder_index.html

@@ -49,7 +49,7 @@
             {% if child.tags %}
             <div class="flex flex-wrap gap-1">
               {% for tag in child.tags %}
-              {% set tag_slug = tag.lstrip('#').lower() %}
+              {% set tag_slug = normalize_tag(tag) %}
               {% if site.tag_index %}
               <a href="{{ tag_url(tag_slug) }}" class="badge badge-sm badge-ghost hover:badge-primary">{{ tag.lstrip('#') }}</a>
               {% else %}

src/rockgarden/templates/page.html

@@ -26,7 +26,7 @@
                 {% if tags %}
                 <div class="flex flex-wrap gap-1">
                     {% for tag in tags %}
-                    {% set tag_slug = tag.lstrip('#').lower() %}
+                    {% set tag_slug = normalize_tag(tag) %}
                     {% if site.tag_index %}
                     <a href="{{ tag_url(tag_slug) }}" class="badge badge-sm badge-ghost hover:badge-primary">{{ tag.lstrip('#') }}</a>
                     {% else %}

src/rockgarden/urls.py

@@ -3,6 +3,22 @@
 import re
 
 
+def normalize_tag(tag: str) -> str:
+    """Normalize a tag to a URL-safe slug.
+
+    Strips leading '#', lowercases, and replaces any character that is not
+    alphanumeric, hyphen, or underscore with a hyphen. Prevents path traversal
+    via tags containing '/' or '..'.
+
+    Tags 'Python', '#python', and 'python' all normalize to 'python'.
+    Obsidian nested tags like 'character/pc' normalize to 'character-pc'.
+    """
+    slug = tag.lstrip("#").lower()
+    slug = re.sub(r"[^a-z0-9_-]", "-", slug)
+    slug = re.sub(r"-+", "-", slug)
+    return slug.strip("-")
+
+
 def generate_slug(relative_path: str) -> str:
     """Generate URL-safe slug from a relative file path.