iCalendar exports

IcalView sets the text/calendar content type, disables the application layout, and looks for templates in an ics subdirectory. It does not generate events itself.

Enable an export route

In your existing application route scope, enable the extension before connecting routes or calling fallbacks():

$routes->setExtensions(['ics']);

If you already support other extensions, include them in the array. With standard fallback routes, an action such as /events/view/1.ics then receives _ext = ics.

In the action, select the export view for that extension:

if ($this->request->getParam('_ext') === 'ics') {
    $this->viewBuilder()->setClassName(\Calendar\View\IcalView::class);
}

Keep the action's existing record lookup and access checks. Create templates/Events/ics/view.php alongside your normal HTML template:

<?php
use Calendar\Utility\IcalFormatter;

echo IcalFormatter::formatCalendar([
    [
        'uid' => 'event-' . $event->id . '@events.example.com',
        'summary' => $event->title,
        'start' => $event->date instanceof \Cake\I18n\Date
            ? $event->date->format('Y-m-d')
            : $event->date,
        'allDay' => $event->date instanceof \Cake\I18n\Date,
    ],
]);

Use your own domain in the UID. A persistent UID tied to the record lets calendar clients identify the same event after its title or date changes. The generated fallback UID hashes the normalized start, all-day flag, summary, and location, so it changes when those values change. Its date normalization corrects the older locale-dependent algorithm; existing feeds using fallback UIDs will receive new identifiers after this change. Supply persistent UIDs to avoid this dependency on formatter internals.

Formatter inputs

formatCalendar($events, $options) wraps an array of event arrays in a calendar document. Each event requires start; supported optional keys are uid, summary, description, location, url, end, allDay, created, modified, and categories.

Dates accept DateTimeInterface objects, integer Unix timestamps, or parseable nonempty date strings. CakePHP DateTime is supported. Convert CakePHP date-only objects to a Y-m-d string for the formatter. Use explicit timezones for timed events because timezone-free strings use the PHP default timezone.

$payload = [
    [
        'uid' => 'holiday-42@events.example.com',
        'summary' => 'Office closed',
        'start' => '2026-12-24',
        'end' => '2026-12-26',
        'allDay' => true,
        'categories' => ['Holiday'],
    ],
];
echo \Calendar\Utility\IcalFormatter::formatCalendar($payload, [
    'prodid' => '-//Example App//Events//EN',
]);

The all-day example covers December 24 and 25: iCalendar DTEND is exclusive, as defined in RFC 5545. Timed values are emitted in UTC with a Z suffix; all-day values use VALUE=DATE. The formatter escapes text, folds content lines at 75 bytes, and uses CRLF line endings. Pass only trusted values for protocol options such as method and calscale, and valid event URLs.

Options are prodid (default -//cakephp-calendar//Events//EN), method (default null, omitted), and calscale (default GREGORIAN). The formatter handles basic events rather than recurrence rules, attendees, attachments, or timezone definitions. Use another iCalendar library when those are required; its output can still be rendered by IcalView.