Construct epub url

lib/readlist.rb

@@ -9,6 +9,11 @@ class ReadList
 
   module Util
     def extract_id_from_url(url)
+      begin
+        url.match(%r{http://readlists.com/api/v1/readlists/(.*)/})[1]
+      rescue
+        nil
+      end
     end
   end
 
@@ -25,6 +30,8 @@ def self.create
     new({ :url => response.headers[:location], :session_id => session_id })
   end
 
+  include Util
+
   def initialize(params={})
     @url        = params[:url]
     @session_id = params[:session_id]
@@ -60,7 +67,8 @@ def add_article(article_url)
   end
 
   def epub_url
-
+    id = extract_id_from_url(@url)
+    "http://readlists.com/#{id}/download/epub"
   end
 
   private

test/test_readlist.rb

@@ -104,8 +104,15 @@ def test_persists_articles
     assert_requested @stubbed_create_entry
   end
 
+  # :todo move into own unit test
   def test_extracts_id_from_url
-    assert_equal "12345", ReadList::Helper.extract_id_from_url("http://readlists.com/api/v1/readlists/12345/")
+    util = Class.new do
+      include ReadList::Util
+    end.new
+
+    assert_equal "12345",    util.extract_id_from_url("http://readlists.com/api/v1/readlists/12345/")
+    assert_equal "075c62a3", util.extract_id_from_url("http://readlists.com/api/v1/readlists/075c62a3/")
+    assert_equal nil,        util.extract_id_from_url("http://www.bbc.co.uk/news/business-18944097")
   end
 
   def test_exposes_epub_url