Google Calendar Push Notifications SetUp - php

Question

I'm trying to setup a Push Notifications for Google Calendar using PHP and V3 api.
I've got the Auth2.0 Permission and I'm able to create events on google from my application. Now I want to know when a user makes any change on google calendar (CRUD Operations).
This is my code:
private $imageService;
public $google_client;
public $google_calendar;
public function __construct()
{
$this->imageService = new ImageService();
$this->google_client = new Google_Client();
$this->google_client->setApplicationName($_ENV['GOOGLE_APP_NAME']);
$this->google_client->setDeveloperKey($_ENV['GOOGLE_API_KEY']);
$this->google_client->setClientId($_ENV['CLIENT_ID']);
$this->google_client->setClientSecret($_ENV['CLIENT_SECRET']);
$this->google_client->setAccessType('offline');
$this->google_client->setIncludeGrantedScopes(true);
$this->google_client->setScopes(array('email', 'profile', 'https://www.googleapis.com/auth/plus.me', 'https://www.googleapis.com/auth/calendar'));
$this->google_calendar = new Google_Service_Calendar($this->google_client);
}
public function googleCalendarWatch($uuid){
$channel = new Google_Service_Calendar_Channel($this->google_client);
$channel->setId($uuid);
$channel->setType('web_hook');
$channel->setAddress("https://example.com/google/googleNotifications");
$channel->setExpiration("1919995862000");
$this->google_calendar->events->watch('primary', $channel);
}
And this is the output:
Google_Service_Calendar_Channel Object (
[internal_gapi_mappings:protected] => Array ( )
[address] =>
[expiration] => 1426272395000
[id] => aee2b430-34bf-42bc-a597-ada46db42799
[kind] => api#channel
[params] =>
[payload] =>
[resourceId] => 51IKGpOwCJ6EMraQMUc1_04MODk
[resourceUri] => https://www.googleapis.com/calendar/v3/calendars/primary/events?key=AIzaSyBFUvq3OZO6ugAKvz7l8NgLS0V6DUJq8Vc&alt=json
[token] =>
[type] =>
[modelData:protected] => Array ( )
[processed:protected] => Array ( ) )
This far I don't know why address returns null, maybe that's the problem. But I don't know how to fix it.
Also reading this: #26730263 and looking my own code there's no much difference.
I did all the stuff that google says, Register domain, add credentials, api key, push domain allowed and all..

Answer 1

Create a notification channel for every individual resource, then any modification to that resource you will be then notified. Information below is directly from Google (Creating notification channels).
Making watch requests:
Each watchable Google Calendar API resource has an associated watch method at a URI of the following form:
https://www.googleapis.com/**apiName**/**apiVersion**/**resourcePath**/watch
To set up a notification channel for messages about changes to a particular resource, send a POST request to the watch method for the resource.
Each notification channel is associated both with a particular user and a particular resource (or set of resources). A watch request will not be successful unless the current user owns or has permission to access this resource.
Example:
Start watching for changes to a collection of events on a given calendar:
POST https://www.googleapis.com/calendar/v3/calendars/my_calendar#gmail.com/events/watch
Authorization: Bearer auth_token_for_current_user
Content-Type: application/json
{
"id": "01234567-89ab-cdef-0123456789ab", // Your channel ID.
"type": "web_hook",
"address": "https://example.com/notifications", // Your receiving URL.
...
"token": "target=myApp-myCalendarChannelDest", // (Optional) Your channel token.
"expiration": 1426325213000 // (Optional) Your requested channel expiration time.
}
}
Reference: Google (Creating notification channels) (19-Mar-2018).
Address?
Token?

Answer 2

<?php
require __DIR__ . '/vendor/autoload.php';
if (php_sapi_name() != 'cli') {
throw new Exception('This application must be run on the command line.');
}
/**
* Returns an authorized API client.
* #return Google_Client the authorized client object
*/
function getClient()
{
$client = new Google_Client();
$client->setApplicationName('Google Calendar API PHP Quickstart');
$client->setScopes(Google_Service_Calendar::CALENDAR_READONLY);
$client->setAuthConfig('credentials.json');
$client->setAccessType('offline');
$client->setPrompt('select_account consent');
// Load previously authorized token from a file, if it exists.
// The file token.json stores the user's access and refresh tokens, and is
// created automatically when the authorization flow completes for the first
// time.
$tokenPath = 'token.json';
if (file_exists($tokenPath)) {
$accessToken = json_decode(file_get_contents($tokenPath), true);
$client->setAccessToken($accessToken);
}
// If there is no previous token or it's expired.
if ($client->isAccessTokenExpired()) {
// Refresh the token if possible, else fetch a new one.
if ($client->getRefreshToken()) {
$client->fetchAccessTokenWithRefreshToken($client->getRefreshToken());
} else {
// Request authorization from the user.
$authUrl = $client->createAuthUrl();
printf("Open the following link in your browser:\n%s\n", $authUrl);
print 'Enter verification code: ';
$authCode = trim(fgets(STDIN));
// Exchange authorization code for an access token.
$accessToken = $client->fetchAccessTokenWithAuthCode($authCode);
$client->setAccessToken($accessToken);
// Check to see if there was an error.
if (array_key_exists('error', $accessToken)) {
throw new Exception(join(', ', $accessToken));
}
}
// Save the token to a file.
if (!file_exists(dirname($tokenPath))) {
mkdir(dirname($tokenPath), 0700, true);
}
file_put_contents($tokenPath, json_encode($client->getAccessToken()));
}
return $client;
}
// Get the API client and construct the service object.
$client = getClient();
$service = new Google_Service_Calendar($client);
// Print the next 10 events on the user's calendar.
$calendarId = 'primary';
$optParams = array(
'maxResults' => 10,
'orderBy' => 'startTime',
'singleEvents' => true,
'timeMin' => date('c'),
);
$results = $service->events->listEvents($calendarId, $optParams);
$events = $results->getItems();
if (empty($events)) {
print "No upcoming events found.\n";
} else {
print "Upcoming events:\n";
foreach ($events as $event) {
$start = $event->start->dateTime;
if (empty($start)) {
$start = $event->start->date;
}
printf("%s (%s)\n", $event->getSummary(), $start);
}
}
Full Tutorial