EDS4S - Evolution Data Server for Scala

A Scala 3 library for GNOME Evolution Data Server via DBus.

What is it?

EDS4S is a type-safe, functional Scala 3 library for managing calendars and events on Linux systems. It communicates with GNOME's Evolution Data Server through DBus, giving your Scala apps native calendar integration.

Purpose

Type-safe calendar and event management for Scala applications running on Linux desktops. Perfect for building scheduling apps, calendar tools, or any software that needs to read or write calendar data.

Prerequisites

Java 17+, Scala 3.3.x, sbt 1.9.x
Evolution Data Server (installed and running, default on systems utilizing Gnome)

# Ubuntu/Debian
sudo apt install evolution-data-server
# Fedora  
sudo dnf install evolution-data-server
# Arch Linux
sudo pacman -S evolution-data-server

Installation

libraryDependencies += "org.polyvariant" %% "eds4s-core" % "0.1.0"
libraryDependencies += "org.polyvariant" %% "eds4s-dbus" % "0.1.0"

Quick Start

import eds4s.*, eds4s.dbus.DBusCalendarClient
import cats.effect.*, cats.syntax.all.*
import java.time.Instant

object QuickStart extends IOApp.Simple {
  def run: IO[Unit] = 
    DBusCalendarClient.resource[IO].use { client =>
      for {
        calendars <- client.listCalendars
        _ <- IO.println(s"Found ${calendars.size} calendars")
        
        calendar <- client.createCalendar(
          name = "My Calendar", backend = CalendarBackend.Local,
          calendarType = CalendarType.Events, color = Some("#3465A4"))
        
        now <- IO(Instant.now())
        eventId <- client.createEvent(calendar.uid, EventData(
          summary = "Team Meeting", description = Some("Weekly sync"),
          location = Some("Room A"), startTime = now.plusSeconds(3600),
          endTime = Some(now.plusSeconds(7200)), timeZone = Some("Europe/Warsaw"))
        )

        events <- client.getEvents(calendar.uid)
        _ <- IO.println(s"Events: ${events.map(_.summary).mkString(", ")}")
        _ <- client.deleteEvent(calendar.uid, eventId)
        _ <- client.deleteCalendar(calendar.uid)
      } yield ()
    }
}

Common Operations

List Calendars

calendars <- client.listCalendars
calendars.foreach(c => println(s"${c.name} (${c.uid})"))

Create Calendar

calendar <- client.createCalendar(
  name = "Work", backend = CalendarBackend.Local,
  calendarType = CalendarType.Events, color = Some("#FF5500"))

Create Event

eventId <- client.createEvent(calendarUid, EventData(
  summary = "Meeting",
  startTime = Instant.parse("2024-03-15T10:00:00Z"),
  endTime = Some(Instant.parse("2024-03-15T11:00:00Z"))))

Query Events

// All events
events <- client.getEvents(calendarUid, EventQuery.all)

// By text search
events <- client.getEvents(calendarUid, EventQuery.contains("meeting"))

// By time range
events <- client.getEvents(calendarUid, 
  EventQuery.inRange(Instant.parse("2024-03-01T00:00:00Z"),
                     Instant.parse("2024-03-31T23:59:59Z")))

Delete Event/Calendar

client.deleteEvent(calendarUid, eventId, ModificationType.This)
client.deleteCalendar(calendarUid)

API Overview

CalendarClient[F[_]] is the main interface:

Calendar ops: listCalendars, getCalendar, createCalendar, deleteCalendar
Event ops: getEvents, getEvent, createEvent, modifyEvent, deleteEvent

Key types: CalendarInfo, Event, EventData, EventQuery, EventId

polyvariant / eds4s 0.1.0