我制作了一个插件，允许wordpress使用外部api登录。

一切正常，现在我要做的是，当用户第一次登录时，插件会检查它是否已经存在于wp上，如果它还没有存在，它会通过保留用户名、电子邮件和密码来创建一个新用户。

新用户已创建，但我希望它还附带来自外部api的id字段，并将其保存在ACF字段中。

这是迄今为止创建的代码：

<?php

/************************************
 * API Authentication
 ************************************/
add_filter(\'authenticate\', \'au_auth\', 10, 3);

/**
 * Calls external API when user logs in to Wordpress
 *
 * @param $user
 * @param $username
 * @param $password
 * @return bool|false|object|WP_Error|WP_User
 */
function au_auth($user, $username, $password)
{
    $options = get_option(\'au_options\');
    $endpoint = $options[\'au_apiurl\'];

    $user_email_key = \'email\';
    $password_key = \'password\';

    // Makes sure there is an endpoint set as well as username and password
    if (!$endpoint || $user !== null || (empty($username) && empty($password))) {
        return false;
    }

    // Check user exists locally
    $user_exists = wp_authenticate_username_password(null, $username, $password);

    if ($user_exists && $user_exists instanceof WP_User) {
        $user = new WP_User($user_exists);
        return $user;
    }

    // Build the POST request
    $login_data = array(
        $user_email_key => $username,
        $password_key => $password
    );

    $auth_args = array(
        \'method\' => \'POST\',
        \'headers\' => array(
            \'Content-type: application/x-www-form-urlencoded\'
        ),
        \'sslverify\' => false,
        \'body\' => $login_data
    );


    $response = wp_remote_post($endpoint, $auth_args);

    // Token if success; Not used right now
    $response_token = json_decode($response[\'response\'][\'token\'], true);

    $response_code = $response[\'response\'][\'code\'];
    if ($response_code == 400) {
        // User does not exist, send back an error message
        $user = new WP_Error(\'denied\', __("<strong>Error</strong>: Your username or password are incorrect."));
    } else if ($response_code == 200) {
        // External user exists, try to load the user info from the WordPress user table
        $userobj = new WP_User();
        // Does not return a WP_User object but a raw user object
        $user = $userobj->get_data_by(\'email\', $username);
        if ($user && $user->ID) {
            // Attempt to load the user with that ID
            $user = new WP_User($user->ID);
        }
    } else {
        // The user does not currently exist in the WordPress user table.
        // Setup the minimum required user information
        $userdata = array(
            \'user_email\' => $username,
            \'user_login\' => $username,
            \'user_pass\' => $password
        );
        // A new user has been created
        $new_user_id = wp_insert_user($userdata);
        // Assign editor role to the new user (so he can access protected articles)
        wp_update_user(
            array(
                \'ID\' => $new_user_id,
                \'role\' => \'editor\'
            )
        );
        // Load the new user info
        $user = new WP_User ($new_user_id);
    }
}
// Useful for times when the external service is offline
remove_action(\'authenticate\', \'wp_authenticate_username_password\', 20);

return $user;
}