Added rss caching.

app/controllers/rss_controller.rb

@@ -5,19 +5,32 @@ class RssController < ApplicationController
   def fetch
     url   = params[:url]
     limit = params[:limit] || 10
-    response = Net::HTTP.get_response( URI.parse(url) )
-    if response.code.to_s != '200'
-      render :json => { :message => "failed to fetch #{url}, code: #{response.code}"}, :status => :unprocessable_entity
-      return
+    
+    cache_key = 'rss::' + url
+    items = Rails.cache.read( cache_key )
+    if !items
+      response = Net::HTTP.get_response( URI.parse(url) )
+      if response.code.to_s != '200'
+        render :json => { :message => "failed to fetch #{url}, code: #{response.code}"}, :status => :unprocessable_entity
+        return
+      end
+      rss     = SimpleRSS.parse response.body
+      items   = []
+      fetched = 0
+      rss.items.each { |item|
+        record = {
+          :id        => item.id,
+          :title     => item.title,
+          :summary   => item.summary,
+          :link      => item.link,
+          :published => item.published
+        }
+        items.push record
+        fetched += 1
+        break item if fetched == limit.to_i
+      }
+      Rails.cache.write( cache_key, items, :expires_in => 4.hours )
     end
-    rss     = SimpleRSS.parse response.body
-    items   = []
-    fetched = 0
-    rss.items.each { |item|
-      items.push item
-      fetched += 1
-      break item if fetched == limit.to_i
-    }
     render :json => { :items => items }
   end