wp_initialize_site( int|WP_Site $site_id, array $args = array() ): true|WP_Error

Description

Compatibility

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

Parameters

$site_idint|WP_Site

Site ID or object.

$argsarrayoptional

Arguments to modify the initialization behavior.Default: array()

• $user_idint

  Required. User ID for the site administrator.

• $titlestringdefault: is 'Site %d' where %d is the site ID

  Site title.

• $optionsarraydefault: empty array

  Custom option $key => $value pairs to use.

• $metaarraydefault: empty array

  Custom site metadata $key => $value pairs to use.

Return value

true|WP_Error

True on success, or error object on failure.

Performance profile

How much work a call to wp_initialize_site() 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

Moderate

Reads stored settings via get_network_option(), cached per request but not free on a cold cache.

Scaling

Constant

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

Instructions

14–242

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 273.

Plugin surface

1 hook

Third-party callbacks on 'wp_initialize_site_args' 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
• optionnetwork optionget_network_option()called directly
• cacheobject cachewp_cache_switch_to_blog()one call below wp_initialize_site()
• serializeserialisationmaybe_unserialize()one call below wp_initialize_site()

Further down the call graph this can also reach query 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 · 195 distinct outcomes

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

Hooks and filters fired · 1

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

1. 1
   apply_filters( wp_initialize_site_args )filterline 694 (+41 into the body)

   Filters the arguments for initializing a site.

Uses · 29

• __()Retrieves the translation of $text.
• get_site()Retrieves site data given a site ID or site object.
• wp_is_site_initialized()Checks whether a site is initialized.
• get_network()Retrieves network data given a network ID or network object.
• wp_parse_args()Merges user defined arguments into defaults array.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• wp_installing()Checks or sets whether WordPress is in "installation" mode.
• get_current_blog_id()Retrieves the current site ID.
• switch_to_blog()Switches the current blog.
• make_db_current_silent()Updates the database tables to a new schema, but without displaying results.
• is_subdomain_install()Whether a subdomain configuration is enabled.
• get_home_url()Retrieves the URL for a given site where the front end is accessible.

Source code

View on Trac ↗View on GitHub ↗

653function wp_initialize_site( $site_id, array $args = array() ) {654	global $wpdb, $wp_roles;655 656	if ( empty( $site_id ) ) {657		return new WP_Error( 'site_empty_id', __( 'Site ID must not be empty.' ) );658	}659 660	$site = get_site( $site_id );661	if ( ! $site ) {662		return new WP_Error( 'site_invalid_id', __( 'Site with the ID does not exist.' ) );663	}664 665	if ( wp_is_site_initialized( $site ) ) {666		return new WP_Error( 'site_already_initialized', __( 'The site appears to be already initialized.' ) );667	}668 669	$network = get_network( $site->network_id );670	if ( ! $network ) {671		$network = get_network();672	}673 674	$args = wp_parse_args(675		$args,676		array(677			'user_id' => 0,678			/* translators: %d: Site ID. */679			'title'   => sprintf( __( 'Site %d' ), $site->id ),680			'options' => array(),681			'meta'    => array(),682		)683	);684 685	/**686	 * Filters the arguments for initializing a site.687	 *688	 * @since 5.1.0689	 *690	 * @param array      $args    Arguments to modify the initialization behavior.691	 * @param WP_Site    $site    Site that is being initialized.692	 * @param WP_Network $network Network that the site belongs to.693	 */694	$args = apply_filters( 'wp_initialize_site_args', $args, $site, $network );695 696	$orig_installing = wp_installing();697	if ( ! $orig_installing ) {698		wp_installing( true );699	}700 701	$switch = false;702	if ( get_current_blog_id() !== $site->id ) {703		$switch = true;704		switch_to_blog( $site->id );705	}706 707	require_once ABSPATH . 'wp-admin/includes/upgrade.php';708 709	// Set up the database tables.710	make_db_current_silent( 'blog' );711 712	$home_scheme    = 'http';713	$siteurl_scheme = 'http';714	if ( ! is_subdomain_install() ) {715		if ( 'https' === parse_url( get_home_url( $network->site_id ), PHP_URL_SCHEME ) ) {716			$home_scheme = 'https';717		}718		if ( 'https' === parse_url( get_network_option( $network->id, 'siteurl' ), PHP_URL_SCHEME ) ) {719			$siteurl_scheme = 'https';720		}721	}722 723	// Populate the site's options.724	populate_options(725		array_merge(726			array(727				'home'        => untrailingslashit( $home_scheme . '://' . $site->domain . $site->path ),728				'siteurl'     => untrailingslashit( $siteurl_scheme . '://' . $site->domain . $site->path ),729				'blogname'    => wp_unslash( $args['title'] ),730				'admin_email' => '',731				'upload_path' => get_network_option( $network->id, 'ms_files_rewriting' ) ? UPLOADBLOGSDIR . "/{$site->id}/files" : get_blog_option( $network->site_id, 'upload_path' ),732				'blog_public' => (int) $site->public,

Changelog

Introduced in 5.1.0. 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 7.0.4 tag, from src/wp-includes/ms-site.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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