Google calendar api user defined id using php - php

Question

I am creating hundreds of calendars and than assigning users. I need to update that calendars regularly so I need to create custom ID's for each calendar. No matter what I use it comes back as an invalid ID
Below is my Script in PHP
require_once __DIR__ . '/vendor/autoload.php';
define('APPLICATION_NAME', 'Assignments Calendar');
putenv('GOOGLE_APPLICATION_CREDENTIALS=' . __DIR__ . '/Assignment_Calendars-701dce094981.json');
define('SCOPES', implode(' ', array(
Google_Service_Calendar::CALENDAR)
));
$client = new Google_Client();
$client->useApplicationDefaultCredentials();
$client->setScopes(SCOPES);
$calendarServiceAccount = new Google_Service_Calendar($client);
$calendarId="abcdefghijklmnopqrstuvwxyz1234567890";
$newCalendar = new Google_Service_Calendar_Calendar();
$newCalendar->setSummary("testing");
$newCalendar->setTimeZone('America/Chicago');
$newCalendar->setId($calendarId);
$calendar = $calendarServiceAccount->calendars->insert($newCalendar);
My Error message is
PHP Fatal error: Uncaught Google_Service_Exception: {
"error": {
"errors": [
{
"domain": "global",
"reason": "invalid",
"message": "Invalid resource id value."
}
],
"code": 400,
"message": "Invalid resource id value."
}
}
No matter what I change the $calendarId to it get the same error. If I remove
$newCalendar->setId($calendarId); it works perfectly

Answer 1

You can't assign a custom ID, the ID of a calendar is defined by the API. See API reference.
You will have to create the calendar, read the $calendar->id value after the insert call and store it somewhere to link it to the user by any means.