FINALLY! RailsICalendar ical ics publish with ruby on rails

Das hat echt was Nerven gekostet, aber ich bin mehr als zufrieden mit dem Resultat.

Ich darf vorstellen: Wenn man seinen Kalender in Mac OS X (z. B. per Webdav) auf seinen Server lädt (bzw. synchronisiert) und auf diesem Server auch Ruby on Rails läuft, dann kann man seinen Kalender jetzt auf seiner Webseite veröffentlichen.

In fact I just realize I should better speak english, because someone’s German might be somewhat rusty :)

So again: You have ics files on your server (e.g. via webdav) and Ruby on Rails is running? Great, let’s publish your calendar. The idea came from the great PHPicalendar script.

This is what it will somewhat look like:

I am sorry to not have made a plugin out of this yet, but, hey, the basics are there, help yourself :) If you have any questions feel free to comment.

Requirements:

Vpim plugin with sudo gem install vpim

Features:

Read several ICS files from a directory on the server
Parse all the ical events in them
Cache the current calendar in yaml files
(The cache will be refreshed when a ICS file was updated meanwhile)
HTML will be presented for the calendar
Currently you can only choose a date and see the next X days

A word on recurrence of events

It does do most of the recurrence rules!
Specifically: All that VPIM supports
PLUS: EXDATE is also supported!

The Code

Initializer (config/initializers/any_filename.rb)

# Path to icalendar *.ics files on your server
PATH_ICS       = "#{RAILS_ROOT}/private/calendars/"
PATH_ICS_CACHE = "#{RAILS_ROOT}/tmp/calendars/"
FileUtils::mkdir_p(PATH_ICS)       unless File.exists?(PATH_ICS)
FileUtils::mkdir_p(PATH_ICS_CACHE) unless File.exists?(PATH_ICS_CACHE)

Controller (app/controllers/calendars_controller.rb)

require 'vpim'
class CalendarsController < ApplicationController
 
  def index
    # Load parameters if submitted
    session[:date_year]  = params[:options]["date(1i)"] if !params[:options].blank? && !params[:options]["date(1i)"].empty?
    session[:date_month] = params[:options]["date(2i)"] if !params[:options].blank? && !params[:options]["date(2i)"].empty?
    session[:date_day]   = params[:options]["date(3i)"] if !params[:options].blank? && !params[:options]["date(3i)"].empty?
 
    # Load standard if nothing submitted
    session[:date_year]  = Time.now.year  if session[:date_year].blank?
    session[:date_month] = Time.now.month if session[:date_month].blank?
    session[:date_day]   = Time.now.day   if session[:date_day].blank?
 
    # Set variables
    @scope     = 7
    @events   = []
    @today    = Time.gm(session[:date_year], session[:date_month], session[:date_day])
    cachefile = File.join(PATH_ICS_CACHE, "#{@today.to_s(:ical)}_#{@scope}.yml")
 
    # Kill cache if outdated
    if File.exists?(cachefile)
      killcache = false
      Dir.glob(File.join(PATH_ICS, '*.ics')).each do |file|
        killcache = true if File.mtime(file) > File.mtime(cachefile)
      end
      if killcache
        Dir.glob(File.join(PATH_ICS_CACHE, '*.*')).each do |file|
          File.delete(file)
        end
      end
    end
 
    # Load calendar from cache
    if File.exists?(cachefile)
      @events = YAML.load_file cachefile 
    else
      # No cache, parse each icalendar *.ics file in PATH_ICS and check for event occurences
      Dir.glob(File.join(PATH_ICS, '*.ics')).each do |file|
        category = File.basename(file, '.ics')
        Vpim::Icalendar.decode(File.open(file)).each do |calendar|
          calendar.components do |event|
            for day in 0..@scope
              if start = event.occurs_in?(@today+(60*60*24*day), @today+(60*60*24)+(60*60*24*day))
                myend = start + (event.dtend - event.dtstart)
                @events < < {
                  'category' => category,
                  'day'      => day,
                  'start'    => start,
                  'duration' => ((event.dtend - event.dtstart) / 60).round, # In minutes
                  'end'      => myend,
                  'allday'   => start.hour == 0 && start.min == 0 && start.sec == 0 && myend.hour == 0 && myend.min == 0 && myend.sec == 0,
                  'data'     => event
                }
              end
            end
          end
        end
      end
      @events = @events.uniq # Just in case :)
      # Save cache
      File.open(cachefile, 'w') { |f| YAML.dump(@events, f) }
    end
  end
 
end

Single View (view/calendars/index.html.erb)

< %
  width  = 110      # Width of one day
  height = 6        # height of 15 minutes in pixels
  buffer = 28       # free space for dates in day column (at top of each day)
  minh   = 20       # Minimum of event height
  cutmornings = 120 # I don't have events between 0:00 and 6:00, cut these pixels off
%>
 
<div id="action">
 
< % for day in 0...@scope + 1 do 
  today = (@today+(60*60*24*day))
  case today.wday  
    when 0  
      dayclass = 'class="sunday"'
    when 6  
      dayclass = 'class="saturday"'
    else  
      dayclass = 'class="otherday"'
  end
  %>
  <div id="ical_day" <%= dayclass %>
    style=" width:  < %= width %>px;
            height: < %= height*96 + buffer - cutmornings %>px;
            left:   < %= day*width + day*10 %>px;">
    < % if today.year == Time.now.year && today.month == Time.now.month && today.day == Time.now.day %>
      <b>< %= 'Today' %></b>
    < % else %>
      < %= _(today.strftime("%a")) +', '+ today.to_s(:date) %>
    < % end %>
  </div>
< % end %>
 
< % tops = Array.new(@scope + 1, '')
@events.each do |event|
 
  # Exclude recurrence rule hack
  today = (@today+(60*60*24*event['day']))
  exme = false
  event['data'].propvaluearray('EXDATE').each do |exdate|
    exdate = exdate.to_time
    exme = true if today.year == exdate.year && today.mon == exdate.mon && today.day == exdate.day
  end
  next if exme # Skip this event
 
  if event['allday']
    # All-day events will be inserted later
    tops[event['day']] += '&nbsp; ' + event['data'].summary.to_s + '<br/>'
  else 
    eventheight = ((event['duration']/15)*height).round
    eventheight = minh if eventheight < minh
    %>
    <div id="ical_event"
      style=" background: #<%= eventcolor(event['category']) %>;
              width:  < %= width-2 %>px;
              height: < %= eventheight.to_s %>px;
              top:    < %= event['start'].hour*height*4 + (event['start'].min/15)*6 + buffer - cutmornings %>px;
              left:   < %= event['day']*width + event['day']*10 %>px;">
      < %= '<b>'+ event['start'].to_s(:time) +' - '+ event['end'].to_s(:time) +'<br />' %>
      < %= event['data'].summary %>
    </div>
  < % end %>
< % end %>
 
< % tops.each_with_index do |top, day| %>
    <div id="ical_event_top"
      style=" width: <%= width-2 %>px;
              height: < %= height %>px;
              top: < %= buffer %>px;
              left: < %= day * width + day * 10 %>px;">
      < %= top %>
    </div>
< % end %>
 
<div id="vertical_spacer" style="height: <%= height*96 + buffer*2 - cutmornings %>px;">&nbsp;</div>
 
</div>

Layout View (views/layouts/calendars.html.erb)

        < % form_tag :controller => 'calendars', :action => nil, :id => nil do |f| %>
          < %= date_select("options", "date", :default => @today, :order => [:day, :month, :year]) %>
            < %= submit_tag 'Show' + ' &raquo;', :class => 'date_button' %>
        < % end %>

Helper (for coloring events) (app/helpers/calendar_helper.rb)

module CalendarsHelper
 
  def eventcolor(category)
    case category  
      when 'Wichtig'   # This is the name of the .ics file
        return 'f66'
      when 'Sonstiges'
        return '4f4'
      when 'Studium'
        return 'fb4'
      when 'Privat'
        return '77f'
      when 'Freunde'
        return 'f4f'
      else  
        return 'fb4'
    end
  end
 
end

Stylesheet (public/stylesheets/calendar.css)

/**************** DIVs ***************************/
 
div#action {
  position: absolute;
  margin-left: 10px;
  margin-top: 10px;
  padding: 4px;
  border-left: 0px;
}
 
div#ical_day {
  position: absolute;
  padding-top: 5px;
  text-align: center;
  font-size: 10px;
}
 
.otherday {
  background: #ddd;
}
 
.sunday {
  background: #fdd;
}
 
.saturday {
  background: #ddf;
}
 
#ical_event {
  position: absolute;
  border: 1px #555 solid;
  background: #fb4;
  font-size: 8px;
  text-align: left;
}
 
#ical_event_top {
  position: absolute;
  border: 0px;
  font-size: 9px;
  font-weight: bold;
  text-align: left;
}
 
/**************** Fonts ***************************/
 
#title {
  float:right;
  color: #ddd;
  margin-top: 30px;
  margin-right: 10px;
  line-height: 11px;
  font-size: 16px;
  text-align: right;
}
#title .description {
  color: #777;
  font-size: 10px;
  margin: 0;
}