Using the google calendar api to delete an event with zend framework


I’m using zend framework’s GData library to work with google calendar api v2 and I’d implemented a solution to add and delete events. The adding of events works well, but deleting them did not. According to zend, the way to delete an event is like this

// Option 1: Events can be deleted directly
$event->delete();
 
// Option 2: Events can be deleted supplying the edit URL of the event
// to the calendar service, if known
$service->delete($event->getEditLink()->href);

Deleting via option #1

So after adding the event via the api, an object of Zend_Gdata_Calendar_EventEntry is returned and I should be able to simply do $event->delete(); to delete the event, but this does not work and returns the following error: “Expected response code 200, got 405. Http method DELETE is not supported by this URL”. It’s what the documentation says to do and it doesn’t work.

Deleting via option #2

So, let’s try the other way by storing the “edit link”. First we add the calendar entry successfully, then take the instance of Zend_Gdata_Calendar_EventEntry that is returned and call the delete as below

$event = $cal->addEvent(/* my own method that adds the event and returns instance of Zend_Gdata_Calendar_EventEntry */);
 
$link = $event->getEditLink()->href;
 
function deleteEventByEditLink($link) {
	$client = getClient();
	$service = new Zend_Gdata_Calendar($client);
 
	try {
		$response = $service->delete($link);
	} catch(Exception $e) {
		//event most likely didn't exist on the calendar. 
		return false;
	}
	return true;
}
 
function getClient() {
	return Zend_Gdata_ClientLogin::getHttpClient(GOOGLE_CALENDAR_USERNAME, GOOGLE_CALENDAR_PASSWORD, Zend_Gdata_Calendar::AUTH_SERVICE_NAME);
}

The $response variable above results in a NULL value and the entry does not delete.

What does work – Yes, how to actually delete events!

I was able to find a working solution by storing the event id rather than the edit link, then loading the event by id through the api and then calling the delete method as below.

/* after adding, extract and save the event id */
$event = $cal->addEvent();
$eventId = $event->id->text;
 
/* deleting */
$result = deleteEventById($eventId);
 
function deleteEventById($eventId) {
	$event = getEventById($eventId);
	try {
		$response = $event->delete();
	} catch(Exception $e) {
		//event most likely didn't exist on the calendar. 
		return false;
	}
	return true;
}
 
function getEventById($eventId) {
	// Create an authenticated HTTP client
	$client = getClient();
	$service = new Zend_Gdata_Calendar($client);
	try {
		return $service->getCalendarEventEntry($eventId);
	} catch (Zend_Gdata_App_Exception $e) {
		echo "Error: " . $e->getMessage();
	}
}
 
function getClient() {
	return Zend_Gdata_ClientLogin::getHttpClient(GOOGLE_CALENDAR_USERNAME, GOOGLE_CALENDAR_PASSWORD, Zend_Gdata_Calendar::AUTH_SERVICE_NAME);
}

Hope this saves somebody six hours of pain. Google calendar has API V3 out that seems to work pretty well, except for the oauth authentication bit… have fun with that.

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