Add podcast rss feed of video recordings

content/videos/rss.xml

@@ -0,0 +1,8 @@
+---
+title: Video Recordings Podcast RSS Feed
+index: false
+---
+<%= podcast_feed(
+    :events => @items.select{|i| event?(i)},
+    :excerpt_limit => 100,
+    ) %>

lib/helpers/rss.rb

@@ -2,6 +2,122 @@
 # encoding: utf-8
 
 module Fosdem
+  def podcast_feed(params = {})
+    require 'builder'
+
+    # Extract parameters
+    events = params[:events] || []
+    excerpt_limit = params.fetch(:excerpt_limit)
+
+    # Define how to find webm video once and reuse
+    webm_link = lambda do |e|
+      e[:links].find { |link| link[:title].start_with?('Video recording (AV1/WebM)') }
+    end
+    vtt_link = lambda do |e|
+      e[:links].find { |link| link[:title].start_with?('Video recording subtitle file (VTT)') }
+    end
+
+    # Filter and sort events by video publish date
+    events.select!(&webm_link)
+    events.select!(&vtt_link)
+    events = events.sort_by do |e|
+      webm_link.call(e)[:created] or
+        raise RuntimeError.new("Cannot build Podcast RSS feed: event with id #{e[:event_id]} has a webm video link with no created attr")
+    end.reverse
+
+    # Check config attributes
+    if @site.config[:base_url].nil?
+      raise RuntimeError.new('Cannot build RSS feed: site configuration has no base_url')
+    end
+
+    last_update = events.any? ? DateTime.parse(webm_link.call(events.first)[:created]) : DateTime.now
+    last_update = last_update.rfc822() # rss preferred format
+
+    buffer = ''
+    xml = Builder::XmlMarkup.new(:target => buffer, :indent => 2)
+
+    year = days.first[:conference_day].year.to_s
+    title = "FOSDEM #{year}"
+    description = 'Video recordings of FOSDEM talks - new episodes are released when videos become available. '\
+      'FOSDEM is a free event for software developers to meet, share ideas and collaborate. '\
+      'Every year, thousands of developers of free and open source software from all over the world gather at the event in Brussels.'
+    organization = 'FOSDEM VZW'
+    author_email = '[email protected]'
+    author_email_rfc = "#{author_email} (FOSDEM Info)"
+    root_url = @site.config[:base_url]
+    year_url = root_url + "/#{year}"
+    podcast_image = "#{year_url}/support/promote/box.png"
+
+    # Build feed
+    xml.instruct!
+    xml.rss(version: '2.0', 'xmlns:atom' => 'http://www.w3.org/2005/Atom',
+            'xmlns:itunes' => 'http://www.itunes.com/dtds/podcast-1.0.dtd',
+            'xmlns:podcast' => 'https://podcastindex.org/namespace/1.0') do
+      xml.channel do
+        xml.link "#{year_url}/"
+        # http://validator.w3.org/appc/docs/warning/MissingAtomSelfLink.html
+        xml.atom :link, href: root_url + @item.path, rel: 'self', type: 'application/rss+xml'
+        xml.title title
+        xml.description description
+        xml.language 'en-us'
+        xml.copyright "#{year} #{organization}"
+        xml.podcast :locked, 'yes'
+        xml.podcast :funding,
+                    'While FOSDEM is primarily funded by sponsors and the sale of t-shirts, '\
+                    'we also gratefully accept voluntary donations.',
+                    url: "#{year_url}/support/donate/"
+        xml.lastBuildDate(last_update)
+        xml.pubDate(last_update)
+        xml.ttl('1800')
+        xml.image do
+          xml.url podcast_image
+          xml.title title
+          xml.link "#{year_url}/"
+        end
+        xml.itunes :type, 'episodic'
+        xml.itunes :subtitle, "All the recordings from this year's event in Brussels."
+        xml.itunes :category, text: 'Technology'
+        xml.itunes :author, organization
+        xml.itunes :summary, description
+        xml.itunes :image, href: podcast_image
+        xml.itunes :owner do
+          xml.itunes :name, organization
+          xml.itunes :email, author_email
+        end
+
+        # Add event recordings as podcast items
+        events.each do |e|
+          video_link = webm_link.call(e)
+          transcript_link = vtt_link.call(e)
+          excerpt = \
+            "<p>#{excerpt_words(html_to_text(e[:abstract]), excerpt_limit, '...')}</p>" \
+            "<p>Speakers: #{e[:speakers].map { |s| speaker(s)[:public_name] }.join(', ')}. " \
+            "Track: #{e[:track_full_name]}. Room: #{e[:room_name]}.</p>"
+          url = url_for(e)
+          next if url.nil?
+
+          xml.item do
+            xml.title       "[#{e[:track_full_name]}] #{e[:title]}"
+            xml.guid        url
+            xml.pubDate     DateTime.parse(video_link[:created]).rfc822()
+            xml.author      author_email_rfc
+            xml.link        url
+            xml.description excerpt
+            xml.enclosure   url: video_link[:url], type: 'video/webm'
+            xml.podcast     :transcript, url: transcript_link[:url], type: 'text/vtt'
+            xml.itunes      :episodetype, 'full'
+            xml.itunes      :author, organization
+            unless e[:subtitle].to_s.strip.empty?
+              xml.itunes :subtitle, e[:subtitle]
+            end
+          end
+        end
+      end
+    end
+
+    buffer
+  end
+
   def rss_feed(params = {})
     require 'builder'
 

lib/helpers/schedule_helpers.rb

@@ -298,6 +298,10 @@ def id(item)
     item.identifier.gsub(%r{/+$}, '').split('/')[-1]
   end
 
+  def event?(item)
+    item.identifier =~ %r{^/schedule/event/[^/]+/$}
+  end
+
   def interview?(item)
     item[:kind] == 'interview' or item.identifier =~ %r{^/interviews?/.+}
   end