wppaste
WordPress

_wp_admin_bar_init(): bool

Since
3.1.0
Source
wp-includes/admin-bar.php:23
Instantiates the admin bar object and set it up as a global for access elsewhere.

Description

UNHOOKING THIS FUNCTION WILL NOT PROPERLY REMOVE THE ADMIN BAR.
For that, use show_admin_bar(false) or the 'show_admin_bar' filter.

Compatibility

WordPress
since 3.1.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Return value

bool
Whether the admin bar was successfully initialized.

Performance profile

How much work a call to _wp_admin_bar_init() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class
Trivial

Touches nothing outside its own arguments.

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
5–26

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 28.

Plugin surface
1 hook

Third-party callbacks on 'wp_admin_bar_class' run inside this call, and their cost is not bounded by anything here.

Called by
0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

  • hookthird-party callbacksapply_filters()called directly

Further down the call graph this can also reach query, option, cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 3 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost _wp_admin_bar_init() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
!is_admin_bar_showing()5is_admin_bar_showing()
is_admin_bar_showing() && !$admin_bar_class17is_admin_bar_showing(), apply_filters()
is_admin_bar_showing() && $admin_bar_class26is_admin_bar_showing(), apply_filters(), ->initialize(), ->add_menus()

Across PHP versions

PHPCompiledExecutedBranchesNotes
8.6-dev285–262
8.5285–262
8.4285–2622 fewer instructions than PHP 8.3
8.3305–282
8.2305–282
8.1305–282
7.4305–282

An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.

Hooks and filters fired · 1

One hook fires while _wp_admin_bar_init() runs, in this order:

  1. apply_filters( wp_admin_bar_class )filterline 42 (+19 into the body)

    Filters the admin bar class to instantiate.

Uses · 2

Source code

View on Trac View on GitHub 

function _wp_admin_bar_init() {	global $wp_admin_bar; 	if ( ! is_admin_bar_showing() ) {		return false;	} 	/* Load the admin bar class code ready for instantiation */	require_once ABSPATH . WPINC . '/class-wp-admin-bar.php'; 	/* Instantiate the admin bar */ 	/**	 * Filters the admin bar class to instantiate.	 *	 * @since 3.1.0	 *	 * @param string $wp_admin_bar_class Admin bar class to use. Default 'WP_Admin_Bar'.	 */	$admin_bar_class = apply_filters( 'wp_admin_bar_class', 'WP_Admin_Bar' );	if ( class_exists( $admin_bar_class ) ) {		$wp_admin_bar = new $admin_bar_class();	} else {		return false;	} 	$wp_admin_bar->initialize();	$wp_admin_bar->add_menus(); 	return true;}

Changelog

Introduced in 3.1.0. Unchanged from 6.7.7 through 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data
Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/admin-bar.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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