How to create ICS in rails and send it as a attchment in a mail?

Question

How to create ICS in rails and send it as a attchment in a mail?

Answer 1

This can be done using the ri_cal gem: In order to create an event ics file you want to create the event:

event = RiCal.Event do
      description "MA-6 First US Manned Spaceflight"
      dtstart     DateTime.parse("2/20/1962 14:47:39")
      dtend       DateTime.parse("2/20/1962 19:43:02")
      location    "Cape Canaveral"
      add_attendee "[email protected]"
      alarm do
        description "Segment 51"
      end
    end

Then you use .export(stream) on the event (this will insert the event to a wrapper calendar that contains only this event, so you don't have to wrap it yourself). The stream can be set to a file that can be attached the way Andy suggested or you can call this method without a stream argument which will return a string that can be put into the attachment as is. That will look something like this:

class UserMailer < ActionMailer::Base
  def send_event_email(user, event)
    attachments['event.ics'] = event.export()
    mail(:to => user.email, :subject => "Calendar event!")
  end
end

Answer 2

With icalendar

Add this gem to your Gemfile

gem 'mail'
gem 'icalendar'

You must config mail gem inside config/enviroment.rb for example for RoR >= 4.2

# Load the Rails application.
require File.expand_path('../application', __FILE__)

# Initialize the Rails application.
Rails.application.initialize!

# Initialize sendgrid
ActionMailer::Base.smtp_settings = {
  :user_name => 'username',
  :password => 'password',
  :domain => 'something.com',
  :address => 'smtp.something.com',
  :port => 587,
  :authentication => :plain,
  :enable_starttls_auto => true
}

User model

has_may :calendar_events

Fields

• fullname
• mail

CalendarEvent model

belongs_to :user

Fields

• title
• description
• start_time
• end_time
• user_id

app/mailers/mail_notifier.rb

class MailNotifier < ActionMailer::Base
  default from: '[email protected]'
  def send_calendar_event(calendar_event, organizer)
    @cal = Icalendar::Calendar.new
    @cal.event do |e|
      e.dtstart = calendar_event.start_time
      e.dtend = calendar_event.end_time
      e.summary = calendar_event.title
      e.organizer = "mailto:#{organizer.mail}"
      e.organizer = Icalendar::Values::CalAddress.new("mailto:#{organizer.mail}", cn: organizer.fullname)
      e.description = calendar_event.description
    end
    mail.attachments['calendar_event.ics'] = { mime_type: 'text/calendar', content: @cal.to_ical }
    mail(to: calendar_event.user.mail,
    subject: "[SUB] #{calendar_event.description} from #{l(calendar_event.start_time, format: :default)}")
  end
end

Now you can call MailNotifier from controller with the following code

MailNotifier.send_calendar_event(@calendar_event, organizer_user).deliver

Answer 3

Using ActionMailer (API documentation), simply generate the file and add it to attachments:

class ApplicationMailer < ActionMailer::Base
  def send_ics(recipient)
    attachments['event.ics'] = File.read('path/to/event.ics')
    mail(:to => recipient, :subject => "Calendar event!")
  end
end

You can do this without actually saving a file to the file system, but I'll leave this exercise up to you.