Calendar integration

On this page you can learn more about integrating with the Nextcloud calendar services.

Access calendars and events

Calendar objects

You can query the contents of calendars in the back end through the calendar manager service. Queries are always scoped to a principal (user) but may follow further search criteria like string matches or date ranges.

Inject the calendar manager into your class. Then you can use newQuery and searchForPrincipal to build and execute a search query.

In the following example you see a basic use case of the calendar query API where specific user’s calendar is searched for any events and tasks during a given duration.

<?php

use OCP\Calendar\IManager;

class MyService {

    /** @var IManager */
    private $calendarManager;

    public function __construct(IManager $calendarManager) {
        $this->calendarManager = $calendarManager;
    }

    public function searchInUserCalendar(string $uid,
                                         string $calendarUri,
                                         DateTimeImmutable $from,
                                         DateTimeImmutable $to): void {
        $principal = 'principals/users/' . $uid;

        // Prepare the query
        $query = $this->calendarManager->newQuery($principal);
        $query->addSearchCalendar($uri);
        $query->setTimerangeStart($from);
        $query->setTimerangeEnd($to);

        // Execute the query
        $objects = $this->calendarManager->searchForPrincipal($query);
    }

}

Study the interface \OCP\Calendar\ICalendarQuery to learn more about other query options.

Calendars

You can access calendars through the IManager. Inject the service, then use the getCalendarsForPrincipal method.

You can either query all calendars of the principal if you omit the second argument, or look for specific calendars only. See the examples below.

<?php

use OCP\Calendar\IManager;

class MyService {

    /** @var IManager */
    private $calendarManager;

    public function __construct(IManager $calendarManager) {
        $this->calendarManager = $calendarManager;
    }

    public function processCalendarData(string $uid): void {
        $principal = 'principals/users/' . $uid;

        // This will find all calendars of the principal
        $calendars = $this->calendarManager->getCalendarsForPrincipal($principal);

        // Work with calendars
    }

    public function processCalendarData(string $uid, string $calendarUri): void {
        $principal = 'principals/users/' . $uid;

        // This will only find specific calendars of the principal
        $calendars = $this->calendarManager->getCalendarsForPrincipal(
            $principal,
            [$calendarUri]
        );

        // Check if the requested calendar was found and work with it
    }

}

The returned objects implement \OCP\Calendar\ICalendar. Study the interface methods to discover what data is available.

Note

All calendars are by default only readable, therefore ICalendar does not offer methods for mutation. Some of the calendars are mutable, however, and they may further extend the interface \OCP\Calendar\ICreateFromString.

Calendar providers

Nextcloud apps can register calendars in addition to the internal calendars of the Nextcloud CalDAV back end. Calendars are only loaded on demand, therefore a lazy provider mechanism is used.

To provide calendar(s) you have to write a class that implements the ICalendarProvider interface.

<?php

use OCP\Calendar\ICalendarProvider;

class CalendarProvider implements ICalendarProvider {

    public function getCalendars(string $principalUri, array $calendarUris = []): array {
        $calendars = [];
        // TODO: Run app specific logic to find calendars that belong to
        //       $principalUri and fill $calendars

        // The provider can simple return an empty array if there is not
        // a single calendar for the principal URI
        if (empty($calendars)) {
            return [];
        }

        // Return instances of \OCP\Calendar\ICalendar
        return $calendars;
    }
}

This CalendarProvider class is then registered in the register method of your Application class with $context->registerCalendarProvider(CalendarProvider::class);.

Write support

Calendars that only return ICalendar are implicitly read-only. If your app’s calendars can be written to, you may implement the ICreateFromString. It will allow other apps to write calendar objects to the calendar by passing the raw iCalendar data as string.

<?php

use OCP\Calendar\ICreateFromString;

class CalendarReadWrite implements ICreateFromString {

    // ... other methods from ICalendar still have to be implemented ...

    public function createFromString(string $name, string $calendarData): void {
        // Write data to your calendar representation
    }

}

Resources

Nextcloud apps can provide resource back ends for the CalDAV server in Nextcloud.

To register a custom back end, create a class that implements \OCP\Calendar\Resource\IBackend.

In the boot method of your Application class you can fetch the \OCP\Calendar\Resource\IManager instance and pass the fully qualified class name of your custom back end to registerBackend.

<?php

use OCP\Calendar\Resource\IManager;

class Application extends App implements IBootstrap {

    public function __construct() {
        parent::__construct('myapp');
    }

    public function register(IRegistrationContext $context): void {
        // ... registration logic goes here ...
    }

    public function boot(IBootContext $context): void {
        /** @var IManager $manager */
        $resourceManager = $serverContainer->get(IManager::class);
        $resourceManager->registerBackend(\OCA\MyApp\ResourceBackend::class);
    }

}

Note

Nextcloud queries the registered back ends only periodically through a background job. If the resources do not show up in the front-end double check if cron jobs are run on your development instance.

Rooms

Nextcloud apps can provide rooms back ends for the CalDAV server in Nextcloud.

To register a custom back end, create a class that implements \OCP\Calendar\Room\IBackend.

In the boot method of your Application class you can fetch the \OCP\Calendar\Room\IManager instance and pass the fully qualified class name of your custom back end to registerBackend.

<?php

use OCP\Calendar\Room\IManager;

class Application extends App implements IBootstrap {

    public function __construct() {
        parent::__construct('myapp');
    }

    public function register(IRegistrationContext $context): void {
        // ... registration logic goes here ...
    }

    public function boot(IBootContext $context): void {
        /** @var IManager $manager */
        $resourceManager = $serverContainer->get(IManager::class);
        $resourceManager->registerBackend(\OCA\MyApp\RoomBackend::class);
    }

}

Note

Nextcloud queries the registered back ends only periodically through a background job. If the rooms do not show up in the front-end double check if cron jobs are run on your development instance.