CalDavBridge — Dolibarr CalDAV infrastructure module

CalDavBridge is a reusable CalDAV infrastructure layer for Dolibarr. It synchronizes remote calendars (BlueMind, Google, or any standards-compliant CalDAV server) into a local cache and provides a push transport (PUT / REPORT / DELETE).

It deliberately contains no business logic: deciding which calendar event maps to which project or third party is left to the consumer modules (e.g. meetingnotes, inno3dashboard). This separation lets several modules share one CalDAV transport instead of each re-implementing it.

Prerequisites

• Dolibarr ≥ 16.0 with the Projects and Third parties modules enabled
• PHP ≥ 7.4
• A reachable CalDAV server (BlueMind, Google Calendar, Nextcloud, etc.)

Installation

1. Deploy the caldavbridge/ folder into htdocs/custom/ of your Dolibarr instance (or upload the ZIP via Home → Setup → Modules → Deploy external module).
2. Activate the module CalDavBridge.
3. After deployment on Cloudron: disable then re-enable the module to run the database migrations.

Configuration

The module exposes infrastructure constants (namespace CALDAVBRIDGE_*):

Constant	Default	Description
CALDAVBRIDGE_PULL_ENABLED	0	Enable the CalDAV pull cron (agenda → local cache)
CALDAVBRIDGE_PULL_WINDOW_DAYS	14	Pull time window: how many days back to scan
CALDAVBRIDGE_EVENT_MIN_DURATION	10	Minimum event duration (minutes) to be captured
CALDAVBRIDGE_EVENT_EXCLUDE_KEYWORDS	["perso","privé","[skip]"]	JSON list of title keywords excluding an event from pull
CALDAVBRIDGE_PULL_MAX_EVENTS	1000	Safety cap: max events processed per run (0 = unlimited)
CALDAVBRIDGE_PULL_MAX_BYTES	8388608	Safety cap: max REPORT response size before a calendar is skipped (8 MB)
CALDAVBRIDGE_CALEVENT_RETENTION_DAYS	365	Days to keep cached calevents before purge

Features

• CalDAV transport (PUT / REPORT / DELETE) against standards-compliant servers
• Pull synchronization of remote calendars into a local cache (llx_caldavbridge_calevent)
• RRULE / EXDATE expansion of recurring events into concrete occurrences
• Pull safety caps (max events, max response size, time window)
• Configurable retention / purge of cached events

Architecture

caldavbridge/
├── core/modules/modCalDavBridge.class.php  # Module descriptor
├── class/
│   ├── calevent.class.php                   # Cached calendar event + occurrence expansion
│   └── rruleexpander.class.php              # RRULE/EXDATE → concrete occurrences
├── sql/                                     # llx_caldavbridge_calevent schema
├── langs/{fr_FR,en_US}/caldavbridge.lang
└── test/RRuleExpanderTest.php

Changelog

See CHANGELOG.md for version history.

Authors & provenance

This module is based on code provided by the Open Source community — first and foremost the Dolibarr ERP/CRM project, of which it is a derivative work, and the wider PHP/CalDAV ecosystem.

• Developed and maintained by inno³ — https://inno3.fr — <hello@inno3.fr>
• Development assisted by Claude Opus 4.8 (Anthropic)

License

GPL-3.0-or-later — © 2026 inno³ <hello@inno3.fr>

As a derivative work of Dolibarr (GPL-3.0-or-later), this module is distributed under the same license. See the LICENSE file for the full text.