CalDav Calendar Viewer

Description

CalDav Calendar Viewer fetches and displays events from any standard iCal (.ics) feed directly on your site using a simple shortcode. It supports multiple calendar feeds, each with its own URL and optional username/password for authenticated endpoints.

Key Features:

  • Multiple Calendar Feeds – Configure as many feeds as you need, each with a unique ID.
  • iCal / RFC 5545 Support – Parses standard .ics calendar feeds including all-day events, times, locations, and descriptions.
  • Recurring Events – Expands RRULE recurrences (DAILY, WEEKLY, MONTHLY, YEARLY) including BYDAY, BYMONTHDAY, INTERVAL, COUNT, UNTIL, and EXDATE.
  • DURATION Support – Derives the end time from a DURATION property when DTEND is absent.
  • Basic Authentication – Supply a username and password per feed for protected calendars.
  • Encrypted Credentials – Passwords are stored using AES-256-CBC encryption in the database.
  • Caching – Configurable cache lifetime reduces external HTTP requests (defaults to 1 hour).
  • Cache Management – View the number of currently cached feed entries and clear them with one click from the admin settings page.
  • Async Loading – Calendar events are fetched via AJAX so the containing page renders immediately.
  • Label / Category Filtering – Filter events by iCal CATEGORIES labels using the label shortcode attribute.
    Accepts a comma-separated list; all plain labels must be present on an event for it to be shown.
    Prefix a label with ! to exclude events that carry that category. Matching is case-insensitive.
  • Clickable Events – Events that carry a URL property in the iCal feed are rendered as clickable links.
  • 7-Day Rolling Window – Automatically fetches and displays only the next 7 days of events.
  • Responsive Event List – Clean event list layout that adapts to all screen sizes.
  • Event Tooltips – Hover over an event to see its description.
  • Description Prefix Filtering – Remove lines from event descriptions that start with configurable prefixes. Useful for hiding internal metadata added by calendar applications.

Configuration

Navigate to Settings CalDav Calendar Viewer in the WordPress admin panel.

Adding a Feed

Click + Add Feed and fill in:

  • Feed ID – A unique lowercase identifier (letters, numbers, hyphens, underscores) used in the shortcode.
  • iCal Feed URL – The full URL to the .ics calendar feed.
  • Username – Username for Basic Authentication. Leave blank for public feeds.
  • Password – Password for Basic Authentication. Stored encrypted. Leave blank to keep the current value.

You can configure multiple feeds — each gets its own ID.

General Settings

  • Cache Lifetime (seconds) – How long fetched calendar data is cached. Set to 0 to disable caching. Default: 3600 (1 hour).
  • Description Line Prefixes to Remove – Newline-separated list of prefixes. Any line in an event’s description that starts with one of these prefixes is removed from the tooltip. Useful for hiding internal metadata added by calendar apps (e.g. X-APPLE-, Reminder:).

Cache Management

The settings page shows how many calendar feeds are currently cached. Use the Clear Cache button to delete all cached responses and force fresh fetches on the next page load.

Usage

Basic Shortcode

[caldcavi_calendar id="my-feed"]

Shortcode Attributes

  • id (required) – The feed ID configured in Settings CalDav Calendar Viewer.
  • label (optional) – A comma-separated list of iCal CATEGORIES values to filter events by. All plain labels
    must be present on an event for it to be shown. Prefix a label with ! to exclude events that carry that category.
    Matching is case-insensitive. Omit to show all events.

Examples

[caldcavi_calendar id="team-calendar"]

[caldcavi_calendar id="hr-events"]

[caldcavi_calendar id="team-calendar" label="Work"]

[caldcavi_calendar id="team-calendar" label="Work,Important"]

[caldcavi_calendar id="team-calendar" label="Work,!Cancelled"]

[caldcavi_calendar id="team-calendar" label="!Private"]

Installation

  1. Upload the caldav-calendar-viewer folder to the /wp-content/plugins/ directory, or install it directly through the WordPress plugin screen.
  2. Activate the plugin through the Plugins screen in WordPress.
  3. Go to Settings CalDav Calendar Viewer to add your calendar feeds.
  4. Add the [caldcavi_calendar id="your-feed-id"] shortcode to any page or post.

FAQ

What iCal formats are supported?

The plugin supports any standard iCal feed following RFC 5545 (.ics files). This includes feeds from Google Calendar, Microsoft Outlook/Exchange, Nextcloud, Apple Calendar, and most other calendar applications.

Does it work with password-protected calendars?

Yes. Each feed can be configured with a username and password for HTTP Basic Authentication. Credentials are stored encrypted using AES-256-CBC.

Can I display multiple calendars on the same page?

Yes. Configure multiple feeds in the settings, then use separate shortcodes:

[caldcavi_calendar id="team"]
[caldcavi_calendar id="holidays"]

Can I filter events by category or label?

Yes. Use the label attribute with a comma-separated list of iCal CATEGORIES values. All plain labels must be
present on an event for it to appear. Prefix a label with ! to exclude events carrying that category.
The match is case-insensitive:

[caldcavi_calendar id="team" label="Work"]
[caldcavi_calendar id="team" label="Work,Important"]

If your calendar application does not populate the CATEGORIES field, all events are shown regardless of the label attribute.

How often is the calendar data refreshed?

By default, fetched data is cached for 1 hour (3600 seconds). You can change this in Settings CalDav Calendar Viewer under Cache Lifetime. Set to 0 to fetch fresh data on every page load. You can also manually clear the cache using the Clear Cache button on the settings page.

What if OpenSSL is not available?

The plugin falls back to Base64 encoding for password storage. For production use, the OpenSSL PHP extension is strongly recommended.

Can I style the calendar?

Yes. The calendar uses CSS classes prefixed with caldcavi- that you can override in your theme’s stylesheet or via the WordPress Customizer’s Additional CSS section.

How do I hide internal metadata lines from event tooltips?

Enter line prefixes under Description Line Prefixes to Remove in the General Settings. Any description line that starts with one of those prefixes is stripped from the tooltip. For example, adding X-APPLE- will hide all lines starting with that prefix.

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Contributors & Developers

“CalDav Calendar Viewer” is open source software. The following people have contributed to this plugin.

Contributors

Changelog

1.0.0

  • Initial release.