Theme Functions

Lamb ships a small library of helper functions that theme parts call to render posts, titles, navigation, and the page <head>. This page is the reference for theme authors. For how themes are structured and selected, see Themes.

Using the helpers

The helpers live in the Lamb\Theme namespace. Import each one with a use function statement at the top of the part before you call it:

<?php
use function Lamb\Theme\site_title;
use function Lamb\Theme\part;
use function Lamb\Theme\escape;
?>
<?= site_title() ?>

The built-in themes (base, 2024, 2026) are the best worked examples — copy the use function lines from the part you are overriding.

Globals available in every part

Every part is included from html.php, so these variables are always in scope:

Variable	Type	Contents
`$config`	`array`	Site config: `site_title`, `author_name`, `author_email`, `menu_items`, `feeds`, `theme`, …
`$data`	`array`	Route-specific data, including `$data['posts']` (an array of post beans), `$data['pagination']`, `$data['title']`, and `$data['intro']`
`$template`	`string`	Current template name (`home`, `status`, `tag`, `search`, `404`, …)

Each entry in $data['posts'] is a post bean. The properties you will use most: $bean->title, $bean->transformed (pre-rendered HTML — render this, never re-render body), $bean->description, $bean->created, $bean->updated, $bean->slug, and $bean->id.

Titles and intro

Function	Returns	Description
`site_title($type = 'html')`	`string`	The site title. Wrapped in `<h1>` for HTML output, or plain text when `$type` is not `'html'`.
`page_title($type = 'html')`	`string`	The current page title (`$data['title']`), falling back to the site title.
`site_or_page_title($type = 'html')`	`string`	The page title when one is set, otherwise the site title.
`page_intro()`	`string`	A `<p>` wrapping `$data['intro']` (used on tag and search pages), or `''`.

Posts and content

Function	Returns	Description
`date_created($bean)`	`string`	An `<a class="u-url">` wrapping a `<time class="dt-published">` element, linking to the post permalink with a human-readable timestamp. `''` when the bean has no created date.
`title_link($bean)`	`string`	An `<a class="p-name title-link">` linking the post title to its permalink, or `''` when the post has no title.
`author_card()`	`string`	A representative author `<a class="p-author h-card">` (name from `$config['author_name']`, linked to the site root), or `''` when no author name is set. Emit it inside each post’s `h-entry`.
`link_source($bean)`	`string`	A “Via …” attribution link for feed-ingested posts (uses `source_url`, falling back to the configured feed URL), or `''` for ordinary posts.
`the_reply_context($bean)`	`string`	A “In reply to …” line with the `u-in-reply-to` microformats class when the post replies to another URL, or `''`.
`anchor_headings($html, $top)`	`string`	Shifts the heading levels in a rendered body so its highest heading sits at level `$top`, keeping the rest relative (clamped at `<h6>`). The built-in themes title posts at `<h2>` and pass `$top = 3`.
`related_posts($body, $exclude_id = 0)`	`array`	`['posts' => OODBBean[]]` — posts that share a hashtag with `$body`, excluding `$exclude_id`.
`human_time($timestamp)`	`string`	A relative time string (“3 hours ago”, “Yesterday at 2:15 pm”, or an absolute date for older posts). Takes a Unix timestamp.

Function	Returns	Description
`li_menu_items()`	`string`	`<li><a>` markup for each entry in `$config['menu_items']`, or `''` when none are configured.

Admin actions (logged-in only)

These return '' for anonymous visitors, so they are safe to call unconditionally in a part — the admin controls only appear when you are logged in.

Function	Returns	Description
`action_edit($bean)`	`string`	An “Edit” button for the post.
`action_delete($bean)`	`string`	A delete `<form>` (with CSRF token) for the post.
`action_restore($bean)`	`string`	A “Restore post” `<form>` — used on the Trash view.
`action_preview($bean)`	`string`	A shareable “Preview” link for an unpublished (draft or scheduled) post that has a valid preview token.
`the_entry_form()`	`void`	Echoes the quick-post `<form>` used to create posts.
`csrf_token()`	`string`	The current session CSRF token, creating one if needed. Include it in any `<form>` that POSTs.

Assets and the `<head>`

Function	Returns	Description
`the_styles()`	`void`	Emits the stylesheet. It always loads `styles/styles.css` from the active theme — small stylesheets are inlined, larger ones linked with a cache-busting hash.
`the_scripts()`	`void`	Emits the application `<script>` tags from `src/scripts/`; logged-in users also get the admin scripts. It does not load scripts from the theme directory.
`the_opengraph()`	`void`	Emits OpenGraph/Twitter `<meta>` tags (status pages only).
`the_preconnect()`	`void`	Emits `<link rel="preconnect">` tags for the origins in `$config['preconnect']`.
`the_reply_context($bean)`	`string`	See “Posts and content” above.

Parts and includes

Function	Returns	Description
`part($name, $dir = 'parts')`	`void`	Includes a theme part, falling back to the base theme when the active theme does not provide it. Pass `$dir = ''` for top-level files such as `html`. `$name` and `$dir` are sanitised to `[a-zA-Z0-9-_]`.

<?php use function Lamb\Theme\part; ?>
<?php part('_items'); ?>          <!-- parts/_items.php -->
<?php part('html', ''); ?>        <!-- html.php (top level) -->

Utility

Function	Returns	Description
`escape($str)`	`string`	`htmlspecialchars` for HTML5 output. Call it on every user-supplied value you print.
`redirect_to()`	`string`	The sanitised `?redirect_to=` query value (used by the login form).
`preload_text()`	`string`	The escaped `?text=` query value, used to pre-fill the entry form.

Microformats2 (h-entry / h-card)

The built-in themes mark each post up with microformats2 so Webmention receivers, readers, and other parsers can extract the author, content, permalink and timestamp. If you build a custom _items.php, mirror this markup so your outgoing mentions stay parseable:

class="h-entry" on the post’s <article>.
class="e-content" on the element wrapping the rendered body.
class="p-name" on the post title (the helpers above already add it).
date_created($bean) supplies u-url + dt-published.
author_card() supplies the p-author h-card, placed inside the h-entry.
the_reply_context($bean) supplies u-in-reply-to for replies.

The classes coexist with the schema.org markup the themes also emit, and can be hidden visually (e.g. with screen-reader-text) without affecting parsers.

Webmentions: how Lamb sends and receives mentions — the microformats2 markup above is what receivers parse.
Themes: how themes are structured, the fallback to base, and the part resolution rules.
Site Configuration: the theme key and the config values exposed in $config.
Post Types: how status posts and page-style posts differ, which affects $bean->slug and permalinks.