iCalendar – Internet calendaring, Ruby style

This is a Ruby library for dealing with iCalendar files. Rather than explaining myself, here is the introduction from RFC-2445, which defines the format:

The use of calendaring and scheduling has grown considerably in the last decade. Enterprise and inter-enterprise business has become dependent on rapid scheduling of events and actions using this information technology. However, the longer term growth of calendaring and scheduling, is currently limited by the lack of Internet standards for the message content types that are central to these knowledgeware applications. This memo is intended to progress the level of interoperability possible between dissimilar calendaring and scheduling applications. This memo defines a MIME content type for exchanging electronic calendaring and scheduling information. The Internet Calendaring and Scheduling Core Object Specification, or iCalendar, allows for the capture and exchange of information normally stored within a calendaring and scheduling application; such as a Personal Information Manager (PIM) or a Group Scheduling product.

The iCalendar format is suitable as an exchange format between applications or systems. The format is defined in terms of a MIME content type. This will enable the object to be exchanged using several transports, including but not limited to SMTP, HTTP, a file system, desktop interactive protocols such as the use of a memory- based clipboard or drag/drop interactions, point-to-point asynchronous communication, wired-network transport, or some form of unwired transport such as infrared might also be used.

Now for some examples:

  • Creating iCalendars.

    # Create a calendar with a single event (Method 1)
cal = Icalendar::Calendar.new
event = Icalendar::Event.new

# Set some properties for this event
event.user_id = "[email protected]"
event.timestamp = DateTime.now 
event.start = Date.new(2005, 04, 29)
event.end = Date.new(2005, 04, 28)
event.summary = "Meeting with the man."
event.klass = "PRIVATE"

# Now add it to the calendar
cal.add event 

# Create a calendar with a single event (Method 2)
cal2 = Icalendar::Calendar.new
event = cal.event  # This automatically adds the event to the calendar
event.user_id = "[email protected]"
event.timestamp = DateTime.now 

# Create a calendar with a single event (Method 3)
cal3 = Icalendar::Calendar.new
cal3.event do
  user_id "[email protected]"
  timestamp DateTime.now 
end

# We can output the calendars as strings to write to a file, 
# network port, database etc.
cal_string = cal.to_ical
puts cal_string

Parsing iCalendars:

require 'icalendar'
require 'date'

# Open a file or string to parse
cal_file = File.open("single_event.ics")

# Parser returns an array of calendars because a single file
# can have multiple calendar objects.
cals = Icalendar::Parser.new(cal_file).parse
cal = cals.first

# Now you can access the cal object in just the same way I created it
event = cal.events.first

puts "user_id: " + event.user_id
puts "summary: " + event.summary

Including the iCalendar library when using RubyGem:

begin
  require 'rubygems'
  require_gem 'icalendar', ">= 0.96"
rescue LoadError
  require 'icalendar'
end

Download

The latest release version of this library can be found at

If you would like to help with development or use the most current version you can check out the tree from the subversion repository:

Documentation can be found at

Installation

This library uses rubygems for distribution and installation:

$ gem install icalendar

License

This library is released under the same license as Ruby itself.

Support & Contributions

The iCalendar library homepage is icalendar.rubyforge.org/

There is an [email protected] mailing list that can be used for asking questions, making comments or submitting patches.