Head and body

The <head> used to belong entirely to the theme. Core could not put a title, a description or a canonical on a page — not even on a page core rendered itself — unless the theme happened to print one. Every theme therefore reimplemented the same block, and a theme that got it slightly wrong got it wrong on every page.

`osc_head()`

Call it as the first thing inside <head>:

<head>
<?php osc_head(); ?>
<meta name="theme-color" content="#1b2c5e">
</head>

It prints, in order:

Part	What
`charset`	`<meta charset="utf-8">`
`viewport`	`<meta name="viewport" content="width=device-width, initial-scale=1">`
`title`	`<title>` from `meta_title()`, escaped
`description`	`<meta name="description">`, omitted when there is none
`keywords`	`<meta name="keywords">`, omitted when there is none
`canonical`	`<link rel="canonical">`, omitted when there is none
`feed`	`<link rel="alternate" type="application/rss+xml">` — the current search’s feed on a results page, the site’s elsewhere

and then runs the header hook, which is where enqueued styles and scripts, the robots meta, and everything plugins add come from.

Do not also call osc_run_hook('header') — osc_head() runs it, and a second call prints every enqueued asset twice.

Keeping a part for yourself

Every part is opt-out. Declare only what you want to keep:

osc_add_theme_support('head', array('feed' => false));

Anything not named stays on, so osc_add_theme_support('head') on its own means “core owns all of it”. The declaration is also how core knows your head is core-managed; osc_head() itself works whether or not you declared anything.

`osc_body_class()`

<body <?php osc_body_class(); ?>>

Prints the whole attribute, so a page with no classes prints nothing rather than an empty class="". Core names the page for you:

the page itself — home, search, search-category, item, item-post, item-edit, item-contact, contact, custom, login, register, recover, forgot-password, user-public-profile, error-404
an account view — its own class and a shared user, so one selector reaches the whole signed-in area: user-dashboard, user-profile, user-items, user-alerts, user-change-email, user-change-password, user-change-username
a static page — page and page-{internal name}
the visitor — logged-in or logged-out
the context — lang-{locale}, theme-{theme}, and rtl on a right-to-left locale

Pass your own alongside them, as a string or a list:

<body <?php osc_body_class('has-sidebar'); ?>>

osc_body_class_list() returns the same classes as an array. Both pass through the body_class filter, which receives the computed list and whatever the caller passed — that is where a plugin adds one.

Every class is lowercased and reduced to [a-z0-9_-]; a static page’s internal name is typed by an admin and lands in an attribute, so it is not trusted.

`osc_language_attributes()`

<html <?php osc_language_attributes(); ?>>

Prints lang="en-US" dir="ltr", with dir="rtl" on a right-to-left locale. Filterable through language_attributes. Pass false to get the string back instead of printing it.

None of this is required

A theme that calls none of these behaves exactly as it did. They exist so a theme stops reimplementing them, and so core can describe a page it renders itself.