is_user_member_of_blog( int $user_id = 0, int $blog_id = 0 ): bool
- Since
- MU (3.0.0)
- Source
wp-includes/user.php:1090
Compatibility
- WordPress
- since MU (3.0.0)
- 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.
Parameters
$user_idintoptional- The unique ID of the user. Defaults to the current user.Default:
0 $blog_idintoptional- ID of the blog to check. Defaults to the current site.Default:
0
Return value
bool
Performance profile
How much work a call to is_user_member_of_blog() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Constant
- Instructions
- 12–59
- Plugin surface
- None
- Called by
- 7
Reaches the database via get_user_by().
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 66.
Nothing here hands control to plugin code.
7 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- querycontent query
get_user_by()one call below is_user_member_of_blog() - hookthird-party callbacks
apply_filters()one call below is_user_member_of_blog()
Further down the call graph this can also reach cache and serialize. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 14 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost is_user_member_of_blog() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 12 | none |
empty($user_id) | 15 | get_current_user_id() |
!empty($user_id) && !($user instanceof) | 18 | get_userdata() |
!empty($user_id) && $user instanceof && !is_multisite() | 21 | get_userdata(), is_multisite() |
!($user instanceof) | 21 | get_current_user_id(), get_userdata() |
$user instanceof && !is_multisite() | 24 | get_current_user_id(), get_userdata(), is_multisite() |
!empty($user_id) && $user instanceof && is_multisite() && !empty($blog_id) | 28–36 | get_userdata(), is_multisite(), get_site() |
!empty($user_id) && $user instanceof && is_multisite() && empty($blog_id) | 31–39 | get_userdata(), is_multisite(), get_current_blog_id(), get_site() |
$user instanceof && is_multisite() && !empty($blog_id) | 31–39 | get_current_user_id(), get_userdata(), is_multisite(), get_site() |
$user instanceof && is_multisite() && empty($blog_id) | 34–42 | get_current_user_id(), get_userdata(), is_multisite(), get_current_blog_id(), get_site() |
!empty($user_id) && $user instanceof && is_multisite() && !empty($blog_id) && isset($blog) && !$blog | 42–53 | get_userdata(), is_multisite(), get_site(), get_user_meta() |
!empty($user_id) && $user instanceof && is_multisite() && empty($blog_id) && isset($blog) && !$blog | 45–56 | get_userdata(), is_multisite(), get_current_blog_id(), get_site(), get_user_meta() |
2 further outcomes, up to 59 instructions
$user instanceof && is_multisite() && !empty($blog_id) && isset($blog) && !$blog | 45–56 | get_current_user_id(), get_userdata(), is_multisite(), get_site(), get_user_meta() |
$user instanceof && is_multisite() && empty($blog_id) && isset($blog) && !$blog | 48–59 | get_current_user_id(), get_userdata(), is_multisite(), get_current_blog_id(), get_site(), get_user_meta() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 66 instructions, 12–59 executed per call, 14 branches. The work does not change between versions.
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.
Uses · 6
- get_current_user_id()Gets the current user's ID.
- get_userdata()Retrieves user info by user ID.
- is_multisite()Determines whether Multisite is enabled.
- get_current_blog_id()Retrieves the current site ID.
- get_site()Retrieves site data given a site ID or site object.
- get_user_meta()Retrieves user meta field for a user.
Used by · 7
- WP::handle_404()Set the Headers for 404, if nothing is found for requested URL.
- WP_REST_Application_Passwords_Controller::get_user()Gets the requested user.
- WP_REST_Users_Controller::get_user()Get the user, if the ID is valid.
- is_blog_user()Checks if the current user belong to a given site.
- wp_admin_bar_site_menu()Adds the "Site Name" menu.
- wp_set_all_user_settings()Private. Sets all user interface settings.
- wp_user_settings()Saves and restores user interface settings stored in a cookie.
Source code
function is_user_member_of_blog( $user_id = 0, $blog_id = 0 ) { global $wpdb; $user_id = (int) $user_id; $blog_id = (int) $blog_id; if ( empty( $user_id ) ) { $user_id = get_current_user_id(); } /* * Technically not needed, but does save calls to get_site() and get_user_meta() * in the event that the function is called when a user isn't logged in. */ if ( empty( $user_id ) ) { return false; } else { $user = get_userdata( $user_id ); if ( ! $user instanceof WP_User ) { return false; } } if ( ! is_multisite() ) { return true; } if ( empty( $blog_id ) ) { $blog_id = get_current_blog_id(); } $blog = get_site( $blog_id ); if ( ! $blog || ! isset( $blog->domain ) || $blog->archived || $blog->spam || $blog->deleted ) { return false; } $keys = get_user_meta( $user_id ); if ( empty( $keys ) ) { return false; } // No underscore before capabilities in $base_capabilities_key. $base_capabilities_key = $wpdb->base_prefix . 'capabilities'; $site_capabilities_key = $wpdb->base_prefix . $blog_id . '_capabilities'; if ( isset( $keys[ $base_capabilities_key ] ) && 1 === $blog_id ) { return true; } if ( isset( $keys[ $site_capabilities_key ] ) ) { return true; } return false;}Changelog
Introduced in MU (3.0.0). Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.7.7 tag, from
src/wp-includes/user.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.