How to create a multipart ical email? [Rails] - ruby-on-rails

Question

What I want to achieve is the following:
Send an email with delayed_job containing:
plain-text
html (will be displayed by regular clients which don't understand the inline ical)
"inline" ical which is recognized by Outlook and Thunderbird (with Lightning).
a "regular" ical attachment (for #2)
What works so far/what does'nt:
I am able to send the email via delayed_job with all parts, however:
in Apple's Mail 2 attachments show up (instead of one):
(the html is displayed fine)
in Thunderbird (Lightning) I do get an invitation, just like I want. But the Alarm does not show up.
I have to do some REALLY disgusting gsubs on the rendered iCal in order for the ATTENDEES to show up. (see code snippet)
My thinking:
The first thing to keep in mind is: in order to send an email with attachments from delayed_job
To fix this, remember to add this line to your mailer: content_type "multipart/mixed"
As far as I understand the correct MIME-Type hierarchy would therefore be:
multipart/mixed
multipart/alternative
text/plain
text/html
text/calendar (with: method=REQUEST)
application/ics
Warning! code incoming.
I currently construct this email in the following manner:
Edit: I updated the mailer for Rails 4.2 (attachments must be placed before mail)
in my mailer.rb
def invitation_email(...)
subject = "I suck at email..."
attachments["invite.ics"] = { mime_type: "application/ics",
content: ical_attachment }
email = mail(from: me, to: you, subject: subject)
add_ical_part_to(email)
email
end
def add_ical_part_to(mail)
outlook_body = ical_attachment
mail.add_part(Mail::Part.new do
content_type "text/calendar; method=REQUEST"
body outlook_body
end)
end
and this is how I construct the ical attachments:
def ical_attachment
params_participant = {
"ROLE" => "REQ-PARTICIPANT",
"RSVP" => "FALSE",
"PARTSTAT" => "ACCEPTED"
}
params_invite = {
"CUTYPE" => 'INDIVIDUAL',
"ROLE" => "REQ-PARTICIPANT",
"PARTSTAT" => "NEEDS-ACTION",
"RSVP" => "TRUE"
}
cal = Icalendar::Calendar.new
event = Icalendar::Event.new
event.dtstart #party.from.to_datetime, { "VALUE" => "DATE" }
event.dtend #party.to.to_datetime, { "VALUE" => "DATE" }
event.summary #party.title
event.description #party.description
event.klass "PRIVATE"
event.organizer "cn=#{#user.name} #{#user.surname}:mailto:#{#user.email}"
# THIS DOES NOT WORK
event.alarm.trigger = "-PT5M" # 5 Minutes before...
#party.participations.each do |participation|
str = "cn=#{participation.user.name} #{participation.user.surname}:mailto:#{participation.user.email}"
event.add_attendee(str, params_participant)
end
#party.invitations.each do |invitee|
event.add_attendee("mailto:#{invitee.email}", params_invite)
end
cal.add_event(event)
cal.publish
# I KNOW THIS IS HORRIBLE AND I HATE IT, BUT OTHERWISE THE ATTENDEES DO NOT SHOW UP
cal.to_ical.gsub("ORGANIZER:", "ORGANIZER;").gsub("ACCEPTED:", "ACCEPTED;").gsub("TRUE:", "TRUE;").gsub("PUBLISH", "REQUEST")
end
Any help would be really appreciated!
The email that is being generated: http://pastebin.com/patf05zd
Oh and I'm on:
Rails 3.2.13
The Icalendar gem I'm using

Answer 1

In case someone else happens to come across this, here is what I did:
Instead of the icalendar gem I now use ri_cal. Although I was skeptical because the last commit to that repo was 3 years ago, the google group was a very helpful resource.
Here is how I generate the ical attachment (both inline and normal), which seems to be working fine (although it obviously needs some refactoring :))
def to_ical
# this is horrible
klass = self
cal = RiCal.Calendar do
event = event do
organizer "CN=#{klass.user.name} #{klass.user.surname}:mailto:#{klass.user.email}"
summary klass.party.title
description klass.ical_description
dtstart klass.party.from.utc.to_datetime
dtend klass.party.to.utc.to_datetime
location "See url in description"
security_class klass.security_class
# this is horrible
h = self
klass.party.participations.each do |participation|
h.add_attendee klass.prepare_participant(participation)
end
klass.party.invitations.each do |invitee|
h.add_attendee klass.prepare_invitee(invitee.email)
end
unless klass.party.reminder == 0
alarm do
description "Alarm description"
trigger klass.convert_trigger # -PT1H
action "DISPLAY"
end
end
end
end
# THE HORROR
cal.to_s.gsub("ATTENDEE:", "ATTENDEE")
.gsub("ORGANIZER:", "ORGANIZER;")
.gsub("CALSCALE:GREGORIAN", "CALSCALE:GREGORIAN\nMETHOD:REQUEST\n")
end
The 2 Attachments in Apples Mail still show up, I don't think that can be fixed.

Answer 2

Your second B64 encoded attachment contains a lot of garbage towards the end (attendee field).
That would explain the Thunderbird issue.
Please note that some clients will ignore any alarm you may set on a REQUEST: As an organizer, you should not dictate when each attendee should be reminded of the meeting. That would be a rather rude thing to do.
Regarding the Apple iCal issue, there is not much you can do I'm afraid: Some clients want the ics within, some as an attachment so you have to provide both. Does it show the accept/decline panel on iCal ?