add_user_to_blog

Adds a user to a blog.

Description

(true|WP_Error) add_user_to_blog( (int) $blog_id, (int) $user_id, (string) $role );

Use the action to fire an event when users are added to a blog.

Returns (true|WP_Error)

Parameters (3)

0. $blog_id (int): ID of the blog you're adding the user to.
1. $user_id (int): ID of the user you're adding.
2. $role (string): The role you want the user to have

Usage

if ( !function_exists( 'add_user_to_blog' ) ) { 
    require_once ABSPATH . WPINC . '/ms-functions.php'; 
} 
  
// ID of the blog you're adding the user to. 
$blog_id = -1; 
  
// ID of the user you're adding. 
$user_id = -1; 
  
// The role you want the user to have 
$role = ''; 
  
// NOTICE! Understand what this does before running. 
$result = add_user_to_blog($blog_id, $user_id, $role);

Defined (1)

The function is defined in the following location(s).

/wp-includes/ms-functions.php

function add_user_to_blog( $blog_id, $user_id, $role ) { 
    switch_to_blog($blog_id); 
 
    $user = get_userdata( $user_id ); 
 
    if ( ! $user ) { 
        restore_current_blog(); 
        return new WP_Error( 'user_does_not_exist', __( 'The requested user does not exist.' ) ); 
    } 
 
    if ( !get_user_meta($user_id, 'primary_blog', true) ) { 
        update_user_meta($user_id, 'primary_blog', $blog_id); 
        $site = get_site( $blog_id ); 
        update_user_meta( $user_id, 'source_domain', $site->domain ); 
    } 
 
    $user->set_role($role); 
 
    /** 
     * Fires immediately after a user is added to a site. 
     * 
     * @since MU 
     * 
     * @param int    $user_id User ID. 
     * @param string $role    User role. 
     * @param int    $blog_id Blog ID. 
     */ 
    do_action( 'add_user_to_blog', $user_id, $role, $blog_id ); 
    wp_cache_delete( $user_id, 'users' ); 
    wp_cache_delete( $blog_id . '_user_count', 'blog-details' ); 
    restore_current_blog(); 
    return true; 
}