get_active_blog_for_user( int $user_id ): WP_Site|void

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

$user_idint

The unique ID of the user

Return value

WP_Site|void

The blog object

Performance profile

How much work a call to get_active_blog_for_user() 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

Heavy

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

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

8–118

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 146.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

3

3 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()one call below get_active_blog_for_user()
• optionoption read or writeget_option()one call below get_active_blog_for_user()
• cacheobject cachewp_cache_delete()one call below get_active_blog_for_user()

Further down the call graph this can also reach serialize, 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 · 30 distinct outcomes

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

Uses · 9

• get_blogs_of_user()Gets the sites a user belongs to.
• is_multisite()Determines whether Multisite is enabled.
• get_current_blog_id()Retrieves the current site ID.
• get_user_meta()Retrieves user meta field for a user.
• update_user_meta()Updates user meta field based on user ID.
• get_site()Retrieves site data given a site ID or site object.
• add_user_to_blog()Adds a user to a blog, along with specifying the user's role.
• is_wp_error()Checks whether the given variable is a WordPress Error.
• get_current_network_id()Retrieves the current network ID.

Used by · 3

• WP_Admin_Bar::initialize()Initializes the admin bar.
• get_dashboard_url()Retrieves the URL to the user's dashboard.
• wp_xmlrpc_server::wp_getUsersBlogs()Retrieves the blogs of the user.

Source code

View on Trac ↗View on GitHub ↗

45function get_active_blog_for_user( $user_id ) {46	$blogs = get_blogs_of_user( $user_id );47	if ( empty( $blogs ) ) {48		return;49	}50 51	if ( ! is_multisite() ) {52		return $blogs[ get_current_blog_id() ];53	}54 55	$primary_blog = get_user_meta( $user_id, 'primary_blog', true );56	$first_blog   = current( $blogs );57	if ( false !== $primary_blog ) {58		if ( ! isset( $blogs[ $primary_blog ] ) ) {59			update_user_meta( $user_id, 'primary_blog', $first_blog->userblog_id );60			$primary = get_site( $first_blog->userblog_id );61		} else {62			$primary = get_site( $primary_blog );63		}64	} else {65		// TODO: Review this call to add_user_to_blog too - to get here the user must have a role on this blog?66		$result = add_user_to_blog( $first_blog->userblog_id, $user_id, 'subscriber' );67 68		if ( ! is_wp_error( $result ) ) {69			update_user_meta( $user_id, 'primary_blog', $first_blog->userblog_id );70			$primary = $first_blog;71		}72	}73 74	if ( ( ! is_object( $primary ) )75		|| ( '1' === $primary->archived || '1' === $primary->spam || '1' === $primary->deleted )76	) {77		$blogs = get_blogs_of_user( $user_id, true ); // If a user's primary blog is shut down, check their other blogs.78		$ret   = false;79 80		if ( is_array( $blogs ) && count( $blogs ) > 0 ) {81			$current_network_id = get_current_network_id();82 83			foreach ( (array) $blogs as $blog_id => $blog ) {84				if ( $blog->site_id !== $current_network_id ) {85					continue;86				}87 88				$details = get_site( $blog_id );89				if ( is_object( $details )90					&& '0' === $details->archived && '0' === $details->spam && '0' === $details->deleted91				) {92					$ret = $details;93					if ( (int) get_user_meta( $user_id, 'primary_blog', true ) !== $blog_id ) {94						update_user_meta( $user_id, 'primary_blog', $blog_id );95					}96					if ( ! get_user_meta( $user_id, 'source_domain', true ) ) {97						update_user_meta( $user_id, 'source_domain', $details->domain );98					}99					break;100				}101			}102		} else {103			return;104		}105 106		return $ret;107	} else {108		return $primary;109	}110}

Changelog

Introduced in MU (3.0.0). One change between 6.7.7 and 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 6.9.7 tag, from src/wp-includes/ms-functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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