Generate an RSS feed which can be used with dlvr.it or similar to feed updates to Twitter

.gitignore

@@ -11,3 +11,4 @@
 /archive.json
 /recipes.json
 /recipes/.dirstamp
+/html/updates.rss

html/Makefile

@@ -1,7 +1,7 @@
 SHELL  := /bin/bash
 
-.PHONY: all clean index.md
-all: index.html
+.PHONY: all clean index.md updates.rss
+all: index.html updates.rss
 
 index.md: index.erb
 	erb index.erb > index.md
@@ -9,5 +9,8 @@ index.md: index.erb
 index.html: index.md
 	pandoc --template=template.html --css=style.css -s --mathml -t html --smart index.md > index.html
 
+updates.rss: updates.rss.erb
+	erb updates.rss.erb > updates.rss
+
 clean:
-	-rm -v index.md index.html
+	-rm -v index.md index.html updates.rss

html/updates.rss.erb

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<rss version="2.0"
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/"
+   xmlns:atom="http://www.w3.org/2005/Atom">
+<% base_url = "http://melpa.milkbox.net/" %>
+  <channel>
+    <title>MELPA package updates</title>
+    <link>http://melpa.milkbox.net</link>
+    <atom:link href="<%= base_url %>updates.rss" rel="self" type="application/rss+xml" />
+    <language>en-us</language>
+    <ttl>40</ttl>
+    <description>News about package updates</description>
+    <%
+      require 'json'
+      require 'time'
+      require 'ostruct'
+      JSON.parse(File.open("../archive.json").read).each do |pkgname, info|
+        versions, deps, descr, pkgtype = info
+        version = versions.max.to_s
+        package = OpenStruct.new
+        package.name = pkgname
+        package.version = version
+        package.build_time = Time.new(version[0..3].to_i, version[4..5].to_i, version[6..7].to_i)
+        package.url = "#{base_url}packages/#{pkgname}-#{version}." + (pkgtype == "single" ? "el" : "tar")
+    %>
+      <item>
+        <title>Package update: <%= package.name %> is now at version <%= package.version %></title>
+        <description>The <%= package.name %> package in MELPA has been updated to version <%= package.version %>.</description>
+        <pubDate><%= package.build_time.rfc822 %></pubDate>
+        <guid isPermaLink="true"><%= package.url %></guid>
+        <link><%= package.url %></link>
+      </item>
+    <% end %>
+  </channel>
+</rss>