# Template Functions Reference

URL: /docs/theming/templating/functions/
Section: templating
Tags: reference, templates, filters, jinja2

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Template Functions Reference Bengal provides powerful template filters for querying, filtering, and transforming content collections. Collection Filters These filters work with lists of pages, dictionaries, or any iterable. where Filter items where a key matches a value. Supports comparison operators. Basic Usage: 1 2 3 4 5{# Filter by exact value (default) #} &#123;% set tutorials = site.pages | where(&#39;category&#39;, &#39;tutorial&#39;) %&#125; {# Filter by nested attribute #} &#123;% set track_pages = site.pages | where(&#39;metadata.track_id&#39;, &#39;getting-started&#39;) %&#125; With Comparison Operators: Operator Description Example eq Equal (default) where('status', 'published', 'eq') ne Not equal where('status', 'draft', 'ne') gt Greater than where('date', one_year_ago, 'gt') gte Greater than or equal where('priority', 5, 'gte') lt Less than where('weight', 100, 'lt') lte Less than or equal where('order', 10, 'lte') in Value in list where('tags', 'python', 'in') not_in Value not in list where('status', ['archived'], 'not_in') Operator Examples: 1 2 3 4 5 6 7 8{# Pages newer than a year ago #} &#123;% set recent = site.pages | where(&#39;date&#39;, one_year_ago, &#39;gt&#39;) %&#125; {# Pages tagged with &#39;python&#39; #} &#123;% set python_posts = site.pages | where(&#39;tags&#39;, &#39;python&#39;, &#39;in&#39;) %&#125; {# Exclude archived pages #} &#123;% set live = site.pages | where(&#39;status&#39;, [&#39;archived&#39;, &#39;draft&#39;], &#39;not_in&#39;) %&#125; where_not Filter items where a key does NOT equal a value. 1 2{# Exclude drafts #} &#123;% set published = site.pages | where_not(&#39;draft&#39;, true) %&#125; sort_by Sort items by a key, with optional reverse order. 1 2 3 4 5{# Sort by date, newest first #} &#123;% set recent = site.pages | sort_by(&#39;date&#39;, reverse=true) %&#125; {# Sort alphabetically by title #} &#123;% set alphabetical = site.pages | sort_by(&#39;title&#39;) %&#125; group_by Group items by a key value, returning a dictionary. 1 2 3 4 5 6 7 8 9 10&#123;% set by_category = site.pages | group_by(&#39;category&#39;) %&#125; &#123;% for category, pages in by_category.items() %&#125; &lt;h2&gt;{{ category }}&lt;/h2&gt; &lt;ul&gt; &#123;% for page in pages %&#125; &lt;li&gt;&lt;a href=&quot;{{ page.url }}&quot;&gt;{{ page.title }}&lt;/a&gt;&lt;/li&gt; &#123;% endfor %&#125; &lt;/ul&gt; &#123;% endfor %&#125; limit Take the first N items from a list. 1 2{# Latest 5 posts #} &#123;% set latest = site.pages | sort_by(&#39;date&#39;, reverse=true) | limit(5) %&#125; offset Skip the first N items from a list. 1 2{# Skip first 10 items (pagination page 2) #} &#123;% set page_2 = items | offset(10) | limit(10) %&#125; first / last Get the first or last item from a list. 1 2&#123;% set featured = site.pages | where(&#39;metadata.featured&#39;, true) | first %&#125; &#123;% set oldest = site.pages | sort_by(&#39;date&#39;) | last %&#125; reverse Reverse a list (returns a new list). &#123;% set newest_first = chronological | reverse %&#125; uniq Remove duplicate items while preserving order. &#123;% set unique_tags = all_tags | uniq %&#125; flatten Flatten nested lists into a single list. &#123;% set all_tags = nested_tags | flatten | uniq %&#125; Set Operations Perform set operations on lists. union Combine two lists, removing duplicates. &#123;% set combined = featured | union(recent) %&#125; intersect Get items that appear in both lists. &#123;% set featured_python = featured | intersect(python) %&#125; complement Get items in the first list that are NOT in the second list. &#123;% set regular = all_posts | complement(featured) %&#125; Chaining Filters Filters can be chained for powerful queries: 1 2 3 4 5 6&#123;% set result = site.pages | where(&#39;category&#39;, &#39;tutorial&#39;) | where(&#39;tags&#39;, &#39;python&#39;, &#39;in&#39;) | where(&#39;draft&#39;, false) | sort_by(&#39;date&#39;, reverse=true) | limit(10) %&#125; Quick Reference Filter Purpose Example where(key, val) Filter by value pages \| where('type', 'post') where(key, val, 'gt') Greater than pages \| where('date', cutoff, 'gt') where(key, val, 'in') Value in list pages \| where('tags', 'python', 'in') where_not(key, val) Exclude value pages \| where_not('draft', true) sort_by(key) Sort ascending pages \| sort_by('title') sort_by(key, reverse=true) Sort descending pages \| sort_by('date', reverse=true) group_by(key) Group by value pages \| group_by('category') limit(n) Take first N pages \| limit(5) offset(n) Skip first N pages \| offset(10) first First item pages \| first last Last item pages \| last reverse Reverse order pages \| reverse uniq Remove duplicates tags \| uniq flatten Flatten nested lists nested \| flatten union(list2) Combine lists list1 \| union(list2) intersect(list2) Common items list1 \| intersect(list2) complement(list2) Difference list1 \| complement(list2) Info Seealso Variables Reference — Available template variables Templating — Template basics

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- Author: lbliii
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