/wp-admin/includes/user.php

<?php
/**
 * WordPress user administration API.
 *
 * @package WordPress
 * @subpackage Administration
 */

/**
 * Creates a new user from the "Users" form using $_POST information.
 *
 * @since 2.0
 *
 * @return null|WP_Error|int Null when adding user, WP_Error or User ID integer when no parameters.
 */
function add_user() {
	return edit_user();
}

/**
 * Edit user settings based on contents of $_POST
 *
 * Used on user-edit.php and profile.php to manage and process user options, passwords etc.
 *
 * @since 2.0
 *
 * @param int $user_id Optional. User ID.
 * @return int user id of the updated user
 */
function edit_user( $user_id = 0 ) {
	global $wp_roles, $wpdb;
	$user = new stdClass;
	if ( $user_id ) {
		$update = true;
		$user->ID = (int) $user_id;
		$userdata = get_userdata( $user_id );
		$user->user_login = $wpdb->escape( $userdata->user_login );
	} else {
		$update = false;
	}

	if ( !$update && isset( $_POST['user_login'] ) )
		$user->user_login = sanitize_user($_POST['user_login'], true);

	$pass1 = $pass2 = '';
	if ( isset( $_POST['pass1'] ))
		$pass1 = $_POST['pass1'];
	if ( isset( $_POST['pass2'] ))
		$pass2 = $_POST['pass2'];

	if ( isset( $_POST['role'] ) && current_user_can( 'edit_users' ) ) {
		$new_role = sanitize_text_field( $_POST['role'] );
		$potential_role = isset($wp_roles->role_objects[$new_role]) ? $wp_roles->role_objects[$new_role] : false;
		// Don't let anyone with 'edit_users' (admins) edit their own role to something without it.
		// Multisite super admins can freely edit their blog roles -- they possess all caps.
		if ( ( is_multisite() && current_user_can( 'manage_sites' ) ) || $user_id != get_current_user_id() || ($potential_role && $potential_role->has_cap( 'edit_users' ) ) )
			$user->role = $new_role;

		// If the new role isn't editable by the logged-in user die with error
		$editable_roles = get_editable_roles();
		if ( ! empty( $new_role ) && empty( $editable_roles[$new_role] ) )
			wp_die(__('You can&#8217;t give users that role.'));
	}

	if ( isset( $_POST['email'] ))
		$user->user_email = sanitize_text_field( $_POST['email'] );
	if ( isset( $_POST['url'] ) ) {
		if ( empty ( $_POST['url'] ) || $_POST['url'] == 'http://' ) {
			$user->user_url = '';
		} else {
			$user->user_url = esc_url_raw( $_POST['url'] );
			$user->user_url = preg_match('/^(https?|ftps?|mailto|news|irc|gopher|nntp|feed|telnet):/is', $user->user_url) ? $user->user_url : 'http://'.$user->user_url;
		}
	}
	if ( isset( $_POST['first_name'] ) )
		$user->first_name = sanitize_text_field( $_POST['first_name'] );
	if ( isset( $_POST['last_name'] ) )
		$user->last_name = sanitize_text_field( $_POST['last_name'] );
	if ( isset( $_POST['nickname'] ) )
		$user->nickname = sanitize_text_field( $_POST['nickname'] );
	if ( isset( $_POST['display_name'] ) )
		$user->display_name = sanitize_text_field( $_POST['display_name'] );

	if ( isset( $_POST['description'] ) )
		$user->description = trim( $_POST['description'] );

	foreach ( _wp_get_user_contactmethods( $user ) as $method => $name ) {
		if ( isset( $_POST[$method] ))
			$user->$method = sanitize_text_field( $_POST[$method] );
	}

	if ( $update ) {
		$user->rich_editing = isset( $_POST['rich_editing'] ) && 'false' == $_POST['rich_editing'] ? 'false' : 'true';
		$user->admin_color = isset( $_POST['admin_color'] ) ? sanitize_text_field( $_POST['admin_color'] ) : 'fresh';
		$user->show_admin_bar_front = isset( $_POST['admin_bar_front'] ) ? 'true' : 'false';
	}

	$user->comment_shortcuts = isset( $_POST['comment_shortcuts'] ) && 'true' == $_POST['comment_shortcuts'] ? 'true' : '';

	$user->use_ssl = 0;
	if ( !empty($_POST['use_ssl']) )
		$user->use_ssl = 1;

	$errors = new WP_Error();

	/* checking that username has been typed */
	if ( $user->user_login == '' )
		$errors->add( 'user_login', __( '<strong>ERROR</strong>: Please enter a username.' ));

	/* checking the password has been typed twice */
	do_action_ref_array( 'check_passwords', array ( $user->user_login, & $pass1, & $pass2 ));

	if ( $update ) {
		if ( empty($pass1) && !empty($pass2) )
			$errors->add( 'pass', __( '<strong>ERROR</strong>: You entered your new password only once.' ), array( 'form-field' => 'pass1' ) );
		elseif ( !empty($pass1) && empty($pass2) )
			$errors->add( 'pass', __( '<strong>ERROR</strong>: You entered your new password only once.' ), array( 'form-field' => 'pass2' ) );
	} else {
		if ( empty($pass1) )
			$errors->add( 'pass', __( '<strong>ERROR</strong>: Please enter your password.' ), array( 'form-field' => 'pass1' ) );
		elseif ( empty($pass2) )
			$errors->add( 'pass', __( '<strong>ERROR</strong>: Please enter your password twice.' ), array( 'form-field' => 'pass2' ) );
	}

	/* Check for "\" in password */
	if ( false !== strpos( stripslashes($pass1), "\\" ) )
		$errors->add( 'pass', __( '<strong>ERROR</strong>: Passwords may not contain the character "\\".' ), array( 'form-field' => 'pass1' ) );

	/* checking the password has been typed twice the same */
	if ( $pass1 != $pass2 )
		$errors->add( 'pass', __( '<strong>ERROR</strong>: Please enter the same password in the two password fields.' ), array( 'form-field' => 'pass1' ) );

	if ( !empty( $pass1 ) )
		$user->user_pass = $pass1;

	if ( !$update && isset( $_POST['user_login'] ) && !validate_username( $_POST['user_login'] ) )
		$errors->add( 'user_login', __( '<strong>ERROR</strong>: This username is invalid because it uses illegal characters. Please enter a valid username.' ));

	if ( !$update && username_exists( $user->user_login ) )
		$errors->add( 'user_login', __( '<strong>ERROR</strong>: This username is already registered. Please choose another one.' ));

	/* checking e-mail address */
	if ( empty( $user->user_email ) ) {
		$errors->add( 'empty_email', __( '<strong>ERROR</strong>: Please enter an e-mail address.' ), array( 'form-field' => 'email' ) );
	} elseif ( !is_email( $user->user_email ) ) {
		$errors->add( 'invalid_email', __( '<strong>ERROR</strong>: The e-mail address isn&#8217;t correct.' ), array( 'form-field' => 'email' ) );
	} elseif ( ( $owner_id = email_exists($user->user_email) ) && ( !$update || ( $owner_id != $user->ID ) ) ) {
		$errors->add( 'email_exists', __('<strong>ERROR</strong>: This email is already registered, please choose another one.'), array( 'form-field' => 'email' ) );
	}

	// Allow plugins to return their own errors.
	do_action_ref_array('user_profile_update_errors', array ( &$errors, $update, &$user ) );

	if ( $errors->get_error_codes() )
		return $errors;

	if ( $update ) {
		$user_id = wp_update_user( get_object_vars( $user ) );
	} else {
		$user_id = wp_insert_user( get_object_vars( $user ) );
		wp_new_user_notification( $user_id, isset($_POST['send_password']) ? $pass1 : '' );
	}
	return $user_id;
}

/**
 * Fetch a filtered list of user roles that the current user is
 * allowed to edit.
 *
 * Simple function who's main purpose is to allow filtering of the
 * list of roles in the $wp_roles object so that plugins can remove
 * inappropriate ones depending on the situation or user making edits.
 * Specifically because without filtering anyone with the edit_users
 * capability can edit others to be administrators, even if they are
 * only editors or authors. This filter allows admins to delegate
 * user management.
 *
 * @since 2.8
 *
 * @return unknown
 */
function get_editable_roles() {
	global $wp_roles;

	$all_roles = $wp_roles->roles;
	$editable_roles = apply_filters('editable_roles', $all_roles);

	return $editable_roles;
}

/**
 * Retrieve user data and filter it.
 *
 * @since 2.0.5
 *
 * @param int $user_id User ID.
 * @return object WP_User object with user data.
 */
function get_user_to_edit( $user_id ) {
	$user = new WP_User( $user_id );

	$user->filter = 'edit';

	return $user;
}

/**
 * Retrieve the user's drafts.
 *
 * @since 2.0.0
 *
 * @param int $user_id User ID.
 * @return array
 */
function get_users_drafts( $user_id ) {
	global $wpdb;
	$query = $wpdb->prepare("SELECT ID, post_title FROM $wpdb->posts WHERE post_type = 'post' AND post_status = 'draft' AND post_author = %d ORDER BY post_modified DESC", $user_id);
	$query = apply_filters('get_users_drafts', $query);
	return $wpdb->get_results( $query );
}

/**
 * Remove user and optionally reassign posts and links to another user.
 *
 * If the $reassign parameter is not assigned to an User ID, then all posts will
 * be deleted of that user. The action 'delete_user' that is passed the User ID
 * being deleted will be run after the posts are either reassigned or deleted.
 * The user meta will also be deleted that are for that User ID.
 *
 * @since 2.0.0
 *
 * @param int $id User ID.
 * @param int $reassign Optional. Reassign posts and links to new User ID.
 * @return bool True when finished.
 */
function wp_delete_user( $id, $reassign = 'novalue' ) {
	global $wpdb;

	$id = (int) $id;
	$user = new WP_User( $id );

	// allow for transaction statement
	do_action('delete_user', $id);

	if ( 'novalue' === $reassign || null === $reassign ) {
		$post_types_to_delete = array();
		foreach ( get_post_types( array(), 'objects' ) as $post_type ) {
			if ( $post_type->delete_with_user ) {
				$post_types_to_delete[] = $post_type->name;
			} elseif ( null === $post_type->delete_with_user && post_type_supports( $post_type->name, 'author' ) ) {
				$post_types_to_delete[] = $post_type->name;
			}
		}

		$post_types_to_delete = apply_filters( 'post_types_to_delete_with_user', $post_types_to_delete, $id );
		$post_types_to_delete = implode( "', '", $post_types_to_delete );
		$post_ids = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE post_author = %d AND post_type IN ('$post_types_to_delete')", $id ) );
		if ( $post_ids ) {
			foreach ( $post_ids as $post_id )
				wp_delete_post( $post_id );
		}

		// Clean links
		$link_ids = $wpdb->get_col( $wpdb->prepare("SELECT link_id FROM $wpdb->links WHERE link_owner = %d", $id) );

		if ( $link_ids ) {
			foreach ( $link_ids as $link_id )
				wp_delete_link($link_id);
		}
	} else {
		$reassign = (int) $reassign;
		$wpdb->update( $wpdb->posts, array('post_author' => $reassign), array('post_author' => $id) );
		$wpdb->update( $wpdb->links, array('link_owner' => $reassign), array('link_owner' => $id) );
	}

	// FINALLY, delete user
	if ( is_multisite() ) {
		remove_user_from_blog( $id, get_current_blog_id() );
	} else {
		$meta = $wpdb->get_col( $wpdb->prepare( "SELECT umeta_id FROM $wpdb->usermeta WHERE user_id = %d", $id ) );
		foreach ( $meta as $mid )
			delete_metadata_by_mid( 'user', $mid );

		$wpdb->delete( $wpdb->users, array( 'ID' => $id ) );
	}

	clean_user_cache( $user );

	// allow for commit transaction
	do_action('deleted_user', $id);

	return true;
}

/**
 * Remove all capabilities from user.
 *
 * @since 2.1.0
 *
 * @param int $id User ID.
 */
function wp_revoke_user($id) {
	$id = (int) $id;

	$user = new WP_User($id);
	$user->remove_all_caps();
}

add_action('admin_init', 'default_password_nag_handler');
/**
 * @since 2.8.0
 */
function default_password_nag_handler($errors = false) {
	global $user_ID;
	if ( ! get_user_option('default_password_nag') ) //Short circuit it.
		return;

	//get_user_setting = JS saved UI setting. else no-js-fallback code.
	if ( 'hide' == get_user_setting('default_password_nag') || isset($_GET['default_password_nag']) && '0' == $_GET['default_password_nag'] ) {
		delete_user_setting('default_password_nag');
		update_user_option($user_ID, 'default_password_nag', false, true);
	}
}

add_action('profile_update', 'default_password_nag_edit_user', 10, 2);
/**
 * @since 2.8.0
 */
function default_password_nag_edit_user($user_ID, $old_data) {
	if ( ! get_user_option('default_password_nag', $user_ID) ) //Short circuit it.
		return;

	$new_data = get_userdata($user_ID);

	if ( $new_data->user_pass != $old_data->user_pass ) { //Remove the nag if the password has been changed.
		delete_user_setting('default_password_nag', $user_ID);
		update_user_option($user_ID, 'default_password_nag', false, true);
	}
}

add_action('admin_notices', 'default_password_nag');
/**
 * @since 2.8.0
 */
function default_password_nag() {
	global $pagenow;
	if ( 'profile.php' == $pagenow || ! get_user_option('default_password_nag') ) //Short circuit it.
		return;

	echo '<div class="error default-password-nag">';
	echo '<p>';
	echo '<strong>' . __('Notice:') . '</strong> ';
	_e('You&rsquo;re using the auto-generated password for your account. Would you like to change it to something easier to remember?');
	echo '</p><p>';
	printf( '<a href="%s">' . __('Yes, take me to my profile page') . '</a> | ', admin_url('profile.php') . '#password' );
	printf( '<a href="%s" id="default-password-nag-no">' . __('No thanks, do not remind me again') . '</a>', '?default_password_nag=0' );
	echo '</p></div>';
}