bengal-taxonomy

name	bengal-taxonomy
description	Configures and uses taxonomy (tags, categories, indexes) in Bengal sites. Use when adding tags, categories, or querying content by section, author, or date.

Bengal Taxonomy

Use tags, categories, and built-in indexes to organize and query content.

Frontmatter

Add taxonomy fields to content:

---
title: My Post
tags: [python, bengal, ssg]
category: tutorial
params:
  author: Jane Doe
date: '2026-01-01'
---

Built-in Indexes

Bengal provides O(1) query indexes. Use site.indexes.*.get(key) | resolve_pages:

Index	Key	Use Case
section	Section name	site.indexes.section.get('posts')
author	Author name	site.indexes.author.get('Jane Doe')
category	Category	site.indexes.category.get('tutorial')
date_range	Year or Year-Month	site.indexes.date_range.get('2026-01')

Template Queries

Section listing (e.g., blog posts):

{% let blog_posts = site.indexes.section.get('posts') | resolve_pages %}
{% for post in blog_posts | sort_by('date', reverse=true) %}
  <h2>{{ post.title }}</h2>
  <p>{{ post.description }}</p>
{% end %}

Author archive:

{% let author_posts = site.indexes.author.get('Jane Doe') | resolve_pages %}
<p>{{ author_posts | length }} posts</p>

Monthly archive:

{% let jan_posts = site.indexes.date_range.get('2026-01') | resolve_pages %}

Displaying Tags on a Page

{% let safe_tags = page.tags ?? [] %}
{% for tag in safe_tags %}
  {% if tag %}
  <a href="/tags/{{ tag }}">{{ tag }}</a>
  {% end %}
{% endfor %}

Use ?? [] and {% if tag %} to guard against malformed frontmatter.

Tag Index Pages

Bengal's default theme generates tag index pages at /tags/<tag>/. Ensure your theme has a tag list template. Tags are derived from frontmatter; no config needed.

Checklist

• Add tags, category, params.author to frontmatter
• Use site.indexes for O(1) queries (not where filters)
• Use resolve_pages filter after index lookup
• Guard tag iteration with ?? [] and {% if tag %}

Additional Resources

See references/taxonomy-index.md for index details.