Google calendar + codeigniter - codeigniter

Question

Can anybody tell me where can I found some info about how integrate the google calendar api on a codeigniter framework.
I follow these steps and everything seems had gone fine, but now I don't know how to continue.
All the files I got following the steps (the json, the library and the quickstart.php) I have them on the library folder of the framework... Is it right??
Is there any tutorial about that??
EDIT
I am making some attempts, but I get some errors... for example I tried to follow the example of this page, it looks simply:
$calendarListEntry = $service->calendarList->get('calendarId');
echo $calendarListEntry->getSummary();
But... where is $service got?? I was looking the examples of the client library, and there is a file call simple-query-php where uses a class called Google_Service_Books, where the object´s name is $service, and I tried to make a mix up from the two sources, and the result is this:
require_once('Google/autoload.php');
$client = new Google_Client();
$client->setApplicationName("My_application_name");
$apiKey = "my-client-secret";
$client->setDeveloperKey($apiKey);
$service = new Google_Service_Books($client);
$calendarListEntry = $service->calendarList->get('calendarId');
echo $calendarListEntry->getSummary();
There is a doubt and an error on execution.
The doubt, in this line: $apiKey = "my-client-secret"; it ask by the API-KEY, but I put the client_secret... is it the same?
The error:
A PHP Error was encountered
Severity: Notice
Message: Undefined property: Google_Service_Books::$calendarList
Filename: controllers/dashboard.php
Line Number: 17
Fatal error: Call to a member function get() on a non-object in /var/www/html/prototipo/application/controllers/dashboard.php on line 17
How can I get the correct $service object??
Thank you
RE-EDIT
ANSWER ABOUT APIKEY I think it is not the same, I was typing the client secret obtained after create a OAuth 2.0 client ID credential, and now I created a new credential: API KEY-> server key.
I think that now I am getting the right class to obtain the correct $service object, but I found with one more new problem. What I am trying is this:
require_once('Google/autoload.php');
$client = new Google_Client();
$client->setApplicationName("CalendarTest");
$apiKey = "APY-KEY";
$client->setDeveloperKey($apiKey);
$service = new Google_Service_Calendar($client);
$calendarListEntry = $service->calendarList->get('primary');
echo $calendarListEntry->getSummary();
And the result invoking this method on a browser is this:
Fatal error: Uncaught exception 'Google_Service_Exception' with message 'Error calling GET https://www.googleapis.com/calendar/v3/users/me/calendarList/calendarId?key=MY-APY-KEY: (401) Login Required' in /home/vendor/google/apiclient/src/Google/Http/REST.php:110 Stack trace: #0 /home/vendor/google/apiclient/src/Google/Http/REST.php(62): Google_Http_REST::decodeHttpResponse(Object(Google_Http_Request), Object(Google_Client)) #1 [internal function]: Google_Http_REST::doExecute(Object(Google_Client), Object(Google_Http_Request)) #2 /home/vendor/google/apiclient/src/Google/Task/Runner.php(174): call_user_func_array(Array, Array) #3 /home/vendor/google/apiclient/src/Google/Http/REST.php(46): Google_Task_Runner->run() #4 /home/vendor/google/apiclient/src/Google/Client.php(593): Google_Http_REST::execute(Object(Google_Client), Object(Google_Http_Request)) #5 /home/vendor/google/apiclient/src/Google/Service/Resource.php(240): Google_Client->execute(Object(Google_Http_Request)) #6 /home/vendor/google/apiclient/src/Go in /home/vendor/google/apiclient/src/Google/Http/REST.php on line 110
It is the same result that if I delete the lines about the applicationName and the apikey. Login Required?? What does it mean??
Thank you.

Answer 1

Followed the page http://www.daimto.com/google-calendar-api-with-php-service-account/ and created code like below which is working without errors.
In this code am getting the public holiday list from google calendar for country India
<?php
require 'vendor/autoload.php';
define('APPLICATION_NAME', 'MY_APPLICATION_NAME');
define('CREDENTIALS_PATH', 'credentials/SERVICE_ACCOUNT.p12');
define('EMAIL_ADDRESS', 'holidays#mycalndear.iam.gserviceaccount.com');
/**
* Returns an authorized API client.
* #return Google_Client the authorized client object
*/
function getClient() {
//below lines can be left as it is
$client = new Google_Client();
$client->setApplicationName(APPLICATION_NAME);
$key = file_get_contents(CREDENTIALS_PATH);
// separate additional scopes with a comma
$scopes ="https://www.googleapis.com/auth/calendar.readonly";
$cred = new Google_Auth_AssertionCredentials(
EMAIL_ADDRESS,
array($scopes),
$key
);
$client->setAssertionCredentials($cred);
if($client->getAuth()->isAccessTokenExpired()) {
$client->getAuth()->refreshTokenWithAssertion($cred);
}
return $client;
}
$client = getClient();
$service = new Google_Service_Calendar($client);
$calendarList = $service->calendarList->listCalendarList();
$calendar_id = "en-us.indian#holiday#group.v.calendar.google.com";
// get events
$events = $service->events->listEvents($calendar_id);
foreach ($events->getItems() as $event) {
echo "Summary : ".$event->getSummary()." status : " . $event->getStatus() . " starts at : " . $event->getStart()->date . " ends at : " . $event->getEnd()->date . " html link : " . $event->getHtmlLink() ."\n";
}