# collections URL: /api/rendering/template_functions/collections/ Section: template_functions -------------------------------------------------------------------------------- collections - Bengal window.BENGAL_THEME_DEFAULTS = { appearance: 'dark', palette: 'snow-lynx' }; // Progressive Enhancement System Configuration window.Bengal = window.Bengal || {}; window.Bengal.enhanceBaseUrl = '/bengal/assets/js/enhancements'; window.Bengal.watchDom = true; window.Bengal.debug = false; (function () { try { var defaults = window.BENGAL_THEME_DEFAULTS || { appearance: 'system', palette: '' }; var defaultAppearance = defaults.appearance; if (defaultAppearance === 'system') { defaultAppearance = (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) ? 'dark' : 'light'; } var storedTheme = localStorage.getItem('bengal-theme'); var storedPalette = localStorage.getItem('bengal-palette'); var theme = storedTheme ? 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Provides 15+ functions for filtering, sorting, and transforming lists and dicts. Includes advanced page querying and manipulation functions. View source 18 Functions Functions register Register collection functions with Jinja2 environment. 2 None Caret Right def register(env: Environment, site: Site) -> None Register collection functions with Jinja2 environment. Parameters 2 Name Type Default Description env Environment — site Site — _get_nested_value Get nested value using dot notation (e.g., 'metadata.track_id'). 2 Any Caret Right def _get_nested_value(obj: Any, path: str) -> Any Get nested value using dot notation (e.g., 'metadata.track_id'). Parameters 2 Name Type Default Description obj Any — path str — Returns Any where Filter items where key matches value using specified operator. Supports nested attribute access (e… 4 list[dict[str, Any]] Caret Right def where(items: list[dict[str, Any]], key: str, value: Any = None, operator: str = 'eq') -> list[dict[str, Any]] Filter items where key matches value using specified operator. Supports nested attribute access (e.g., 'metadata.track_id') and comparison operators. Parameters 4 Name Type Default Description items list[dict[str, Any]] — List of dictionaries or objects to filter key str — Dictionary key or attribute path to check (supports dot notation like 'metadata.track_id') value Any None Value to compare against (required for all operators) operator str 'eq' Comparison operator: 'eq' (default), 'ne', 'gt', 'gte', 'lt', 'lte', 'in', 'not in' Returns list[dict[str, Any]] — Filtered list where_not Filter items where key does not equal value. Supports nested attribute access (e.g., 'metadata.tra… 3 list[dict[str, Any]] Caret Right def where_not(items: list[dict[str, Any]], key: str, value: Any) -> list[dict[str, Any]] Filter items where key does not equal value. Supports nested attribute access (e.g., 'metadata.track_id'). Parameters 3 Name Type Default Description items list[dict[str, Any]] — List of dictionaries or objects to filter key str — Dictionary key or attribute path to check (supports dot notation like 'metadata.track_id') value Any — Value to exclude Returns list[dict[str, Any]] — Filtered list group_by Group items by key value. 2 dict[Any, list[dict… Caret Right def group_by(items: list[dict[str, Any]], key: str) -> dict[Any, list[dict[str, Any]]] Group items by key value. Parameters 2 Name Type Default Description items list[dict[str, Any]] — List of dictionaries to group key str — Dictionary key to group by Returns dict[Any, list[dict[str, Any]]] — Dictionary mapping key values to lists of items sort_by Sort items by key. 3 list[Any] Caret Right def sort_by(items: list[Any], key: str, reverse: bool = False) -> list[Any] Sort items by key. Parameters 3 Name Type Default Description items list[Any] — List to sort key str — Dictionary key or object attribute to sort by reverse bool False Sort in descending order (default: False) Returns list[Any] — Sorted list limit Limit items to specified count. 2 list[Any] Caret Right def limit(items: list[Any], count: int) -> list[Any] Limit items to specified count. Parameters 2 Name Type Default Description items list[Any] — List to limit count int — Maximum number of items Returns list[Any] — First N items offset Skip first N items. 2 list[Any] Caret Right def offset(items: list[Any], count: int) -> list[Any] Skip first N items. Parameters 2 Name Type Default Description items list[Any] — List to skip from count int — Number of items to skip Returns list[Any] — Items after offset uniq Remove duplicate items while preserving order. 1 list[Any] Caret Right def uniq(items: list[Any]) -> list[Any] Remove duplicate items while preserving order. Parameters 1 Name Type Default Description items list[Any] — List with potential duplicates Returns list[Any] — List with duplicates removed flatten Flatten nested lists into single list. Only flattens one level deep. 1 list[Any] Caret Right def flatten(items: list[list[Any]]) -> list[Any] Flatten nested lists into single list. Only flattens one level deep. Parameters 1 Name Type Default Description items list[list[Any]] — List of lists Returns list[Any] — Flattened list first Get first item from list. 1 Any Caret Right def first(items: list[Any]) -> Any Get first item from list. Parameters 1 Name Type Default Description items list[Any] — List to get first item from Returns Any — First item or None if list is empty last Get last item from list. 1 Any Caret Right def last(items: list[Any]) -> Any Get last item from list. Parameters 1 Name Type Default Description items list[Any] — List to get last item from Returns Any — Last item or None if list is empty reverse Reverse a list. 1 list[Any] Caret Right def reverse(items: list[Any]) -> list[Any] Reverse a list. Parameters 1 Name Type Default Description items list[Any] — List to reverse Returns list[Any] — Reversed copy of list _get_item_key Get unique key for an item (for set operations). 1 Any Caret Right def _get_item_key(item: Any) -> Any Get unique key for an item (for set operations). Parameters 1 Name Type Default Description item Any — Returns Any union Combine two lists, removing duplicates (set union). Preserves order from first list, then adds ite… 2 list[Any] Caret Right def union(items1: list[Any], items2: list[Any]) -> list[Any] Combine two lists, removing duplicates (set union). Preserves order from first list, then adds items from second list that aren't already present. Parameters 2 Name Type Default Description items1 list[Any] — First list items2 list[Any] — Second list Returns list[Any] — Combined list with duplicates removed intersect Get items that appear in both lists (set intersection). 2 list[Any] Caret Right def intersect(items1: list[Any], items2: list[Any]) -> list[Any] Get items that appear in both lists (set intersection). Parameters 2 Name Type Default Description items1 list[Any] — First list items2 list[Any] — Second list Returns list[Any] — List of items present in both lists complement Get items in first list that are not in second list (set difference). 2 list[Any] Caret Right def complement(items1: list[Any], items2: list[Any]) -> list[Any] Get items in first list that are not in second list (set difference). Parameters 2 Name Type Default Description items1 list[Any] — First list (items to keep) items2 list[Any] — Second list (items to exclude) Returns list[Any] — List of items in first list but not in second list resolve_pages Resolve page paths to Page objects. Used with query indexes to convert O(1) path lookups into Page… 2 list[Any] Caret Right def resolve_pages(page_paths: list[str], site: Site) -> list[Any] Resolve page paths to Page objects. Used with query indexes to convert O(1) path lookups into Page objects: {% set blog_paths = site.indexes.section.get('blog') %} {% set blog_pages = blog_paths | resolve_pages %} PERFORMANCE: Uses cached page path map from Site for O(1) lookups. The cache is automatically invalidated when pages are added/removed. Parameters 2 Name Type Default Description page_paths list[str] — List of page source paths (strings) site Site — Site instance with pages Returns list[Any] — List of Page objects ← Previous autodoc Next → content List © 2025 Bengal ᓚᘏᗢ window.BENGAL_LAZY_ASSETS = { tabulator: '/bengal/assets/js/tabulator.min.js', dataTable: '/bengal/assets/js/data-table.js', mermaidToolbar: '/bengal/assets/js/mermaid-toolbar.9de5abba.js', mermaidTheme: '/bengal/assets/js/mermaid-theme.344822c5.js', graphMinimap: '/bengal/assets/js/graph-minimap.cc7e42e3.js', graphContextual: '/bengal/assets/js/graph-contextual.440e59c6.js' }; window.BENGAL_ICONS = { close: '/bengal/assets/icons/close.911d4fe1.svg', enlarge: '/bengal/assets/icons/enlarge.652035e5.svg', copy: '/bengal/assets/icons/copy.3d56e945.svg', 'download-svg': '/bengal/assets/icons/download.04f07e1b.svg', 'download-png': '/bengal/assets/icons/image.c34dfd40.svg', 'zoom-in': '/bengal/assets/icons/zoom-in.237b4a83.svg', 'zoom-out': '/bengal/assets/icons/zoom-out.38857c77.svg', reset: '/bengal/assets/icons/reset.d26dba29.svg' }; Arrow Up X -------------------------------------------------------------------------------- Metadata: - Author: lbliii - Word Count: 2021 - Reading Time: 10 minutes