# Changelog

All notable changes to this project will be documented in this file.

This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## v2.0.0

The minimum version of Elixir required is 1.17. Support for Elixir 1.15 and 1.16 was
dropped so `ICal` may use the improved date and calendaring APIs introduced in 1.17.

It is recommended to add a timezone database such as `tz` to applications that use
ICal in order to benefit fully from these changes.

- Improvements
  - Recurrence generation was re-written and is now feature complete
    - The entirety of the RFC5545 RRULE specification is supported
    - Works with `ICal.Event`, `ICal.Todo` and `ICal.Journal`
    - Recurrence dates (`RDATE`) are included
    - Excluded dates (`EXDATE`) are respected
  - New functions in `ICal.Alarm`
    - `next_activation/2`: calculates when an alarm should next activate (if ever)
    - `next_alarms/1`: returns all next alarms with activation times for a compoonent with
      alarms (`ICal.Event`, `ICal.Todo`)
- Fixes
  - Gap and ambiguous times are properly handled when a datetime lands in a timezone shift period
  - Properly parse lists of excluded dates
  - Fix serializing of components with status of draft
- Janitorial
  - The dependency on `Timex` was removed
  - Documentation improvements

Contributors to this release include:
- [Matthew Lehner](https://github.com/matthewlehner)
- [Patrick Wendo](https://github.com/W3NDO)

## v1.1.2
- Fixes
  - Fix parsing of Timezones and unknown components with CR/LF line endings

## v1.1.1
- Fixes
  - Fix parsing ICal files with CR/LF line endings (@pedrogarrett)
  - Support "line folding" multiline entries as per the RFC for all line entries

## v1.1.0

- Improvements
  - `ICal.Timezone`: a struct that represents `VTIMEZONE` calendar components
  - `ICal.Todo`: a struct that represents `VTODO` calendar components
  - `ICal.Journal`: a struct that represents `VJOURNAL` calendar components
  - `ICal.RequestStatus`: a struct that represents the `rstatus`, or request status, of a component
    - Added request status support to `ICal.Event`
  - Dates with local times are represented with `NaiveDateTime`s
  - Arbitrary lists of components can be serialized with `ICal.to_ics` without being in an `%ICal{}`
- Fixes
  - `ICal.Deserialize.to_integer` wraps integer parsing for safety in more cases
  - Correct placement of the `:` separator in custom properties with parameters
  - Preserve `priority` and `sequence` properties
  - Parse dates in ICS as Elixir `Date`s, rather than "upgrade" them to `DateTime`s
- Janitorial
  - Improved documentation layout
  - More unit tests

## v1.0.0

- First public release.
- Forked from the Elixir ICalendar library with extensive fixes including:
  - Fixed atom table exhaustion vulnerability by using `to_existing_atom` instead of `to_atom` when processing untrusted ICS files. ([#75](https://github.com/lpil/icalendar/pull/75) by @nixxquality)
  - Support for arbitrary calendar headers via options (e.g., METHOD for RSVP buttons). ([#56](https://github.com/lpil/icalendar/pull/56) by @nickgartmann)
  - Gmail compatibility: ORGANIZER field now uses semi-colon separator as required. ([#70](https://github.com/lpil/icalendar/pull/70) by @maedhr)
  - Added RECURRENCE-ID support for identifying specific instances of recurring events (RFC 5545 Section 3.8.4.4).
  - Add support for the `DTSTAMP` field in events.
    - If not provided, it is initialized to the current UTC DateTime when serializing.
  - Add support for multiple comments in events. The `comment` fields is now `comments` and is an array
  - `to_ics` returns iolists. This prevents unecessary (and slower) string creation when the common use case is to send the data into a file, across a socket, etc. which all consume ioslists natively.
  - Deserialization now produces a Calendar struct
  - Calendar structs contain calendar metadata, such as the ical version, the product id, and method
    - These same fields are serialized out, and this replaces the `options` parameter in `to_ics`
  - Many fixes around serialization/deserialization when it came to escaping and parsing escaped entries, lists, and parameters
- Expanded test suite, with fixtures and ics data in files