install_blog( int $blog_id, string $blog_title = '' )

Description

Compatibility

Deprecated in WordPress 5.1.0. Kept for back-compatibility; avoid it in new code.

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

Parameters

$blog_idint

The value returned by wp_insert_site().

$blog_titlestringoptional

The title of the new site.Default: ''

Performance profile

How much work a call to install_blog() 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

Reaches the database via ->get_results().

Scaling

Constant

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

Instructions

100–147

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 157.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

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

What it touches

• optionnetwork optionget_site_option()called directly
• sqldatabase query->get_results()called directly
• hookthird-party callbacksdo_action()one call below install_blog()
• serializeserialisationmaybe_serialize()one call below install_blog()
• cacheobject cachewp_cache_get()one call below install_blog()

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

What one call costs · 20 distinct outcomes

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

Uses · 17

• _deprecated_function()Marks a function as deprecated and inform when it has been used.
• __()Retrieves the translation of $text.
• get_blogaddress_by_id()Gets a full site URL, given a site ID.
• make_db_current_silent()Updates the database tables to a new schema, but without displaying results.
• populate_options()Create WordPress options and set the default values.
• populate_roles()Execute WordPress role creation for the various WordPress versions.
• untrailingslashit()Removes trailing forward slashes and backslashes if they exist.
• is_subdomain_install()Whether a subdomain configuration is enabled.
• get_site_option()Retrieve an option value for the current network based on name of option.
• set_url_scheme()Sets the scheme for a URL.
• get_home_url()Retrieves the URL for a given site where the front end is accessible.
• get_network()Retrieves network data given a network ID or network object.

Used by · 1

• create_empty_blog()Create an empty blog.

Source code

View on Trac ↗View on GitHub ↗

610function install_blog( $blog_id, $blog_title = '' ) {611	global $wpdb, $wp_roles;612 613	_deprecated_function( __FUNCTION__, '5.1.0' );614 615	// Cast for security.616	$blog_id = (int) $blog_id;617 618	require_once ABSPATH . 'wp-admin/includes/upgrade.php';619 620	$suppress = $wpdb->suppress_errors();621	if ( $wpdb->get_results( "DESCRIBE {$wpdb->posts}" ) ) {622		die( '<h1>' . __( 'Already Installed' ) . '</h1><p>' . __( 'You appear to have already installed WordPress. To reinstall please clear your old database tables first.' ) . '</p></body></html>' );623	}624	$wpdb->suppress_errors( $suppress );625 626	$url = get_blogaddress_by_id( $blog_id );627 628	// Set everything up.629	make_db_current_silent( 'blog' );630	populate_options();631	populate_roles();632 633	// populate_roles() clears previous role definitions so we start over.634	$wp_roles = new WP_Roles();635 636	$siteurl = $home = untrailingslashit( $url );637 638	if ( ! is_subdomain_install() ) {639 640		if ( 'https' === parse_url( get_site_option( 'siteurl' ), PHP_URL_SCHEME ) ) {641			$siteurl = set_url_scheme( $siteurl, 'https' );642		}643		if ( 'https' === parse_url( get_home_url( get_network()->site_id ), PHP_URL_SCHEME ) ) {644			$home = set_url_scheme( $home, 'https' );645		}646	}647 648	update_option( 'siteurl', $siteurl );649	update_option( 'home', $home );650 651	if ( get_site_option( 'ms_files_rewriting' ) ) {652		update_option( 'upload_path', UPLOADBLOGSDIR . "/$blog_id/files" );653	} else {654		update_option( 'upload_path', get_blog_option( get_network()->site_id, 'upload_path' ) );655	}656 657	update_option( 'blogname', wp_unslash( $blog_title ) );658	update_option( 'admin_email', '' );659 660	// Remove all permissions.661	$table_prefix = $wpdb->get_blog_prefix();662	delete_metadata( 'user', 0, $table_prefix . 'user_level', null, true );   // Delete all.663	delete_metadata( 'user', 0, $table_prefix . 'capabilities', null, true ); // Delete all.664}

Changelog

Introduced in MU (3.0.0). 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/ms-deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

Something wrong on this page? Report it and it gets fixed in the next regeneration.