Bind aggregates over scoped tags to their subtree

CccConventions::TAG_SCOPES maps "update" and "pressemitteilung" to /updates
and "disclosure" to /disclosure. Page.aggregate applies the mapping, so an
aggregate over one of those tags is bounded by its subtree regardless of what
the shortcode says. Tags stay unrestricted; positions are publish-gated.

Both RSS actions call Page.aggregate rather than repeating its tag join.

Empty feeds no longer crash: Atom falls back to the current time for the
required <updated>, and the optional dc:date is omitted.

1 files changed, 14 insertions, 20 deletions

diff --git a/app/controllers/rss_controller.rb b/app/controllers/rss_controller.rb
index 655ccba4..c2149d90 100644
--- a/app/controllers/rss_controller.rb
+++ b/app/controllers/rss_controller.rb
@@ -1,19 +1,12 @@
 class RssController < ApplicationController
   
   before_action :get_host
-  
+
   def updates
     expires_in 31.minutes, :public => true
-    
     I18n.locale = I18n.default_locale
-  
-    @items = Page.heads
-      .joins("JOIN taggings ON taggings.taggable_id = pages.id
-            AND taggings.taggable_type = 'Page'
-            AND taggings.context = 'tags'")
-      .joins("JOIN tags ON tags.id = taggings.tag_id")
-      .where("LOWER(tags.name) = ?", "update")
-      .order("published_at DESC").limit(20)
+
+    @items = feed_items("update")
 
     respond_to do |format|
       format.xml {}
@@ -23,16 +16,10 @@ class RssController < ApplicationController
 
   def tag_updates
     expires_in 31.minutes, :public => true
-
     I18n.locale = I18n.default_locale
-    @tag  = params[:tag]
-    @items = Page.heads
-      .joins("JOIN taggings ON taggings.taggable_id = pages.id
-          AND taggings.taggable_type = 'Page'
-          AND taggings.context = 'tags'")
-      .joins("JOIN tags ON tags.id = taggings.tag_id")
-      .where("LOWER(tags.name) = ?", @tag.downcase)
-      .order("published_at DESC").limit(20)
+
+    @tag   = params[:tag]
+    @items = feed_items(@tag)
 
     respond_to do |format|
       format.xml {}
@@ -40,7 +27,14 @@ class RssController < ApplicationController
   end
 
   protected
-    
+
+    def feed_items tag
+      Page.aggregate(:tags => tag.to_s.downcase,
+                     :limit => 20,
+                     :order_by => "published_at",
+                     :order_direction => "DESC")
+    end
+
     def get_host
       @host = request.protocol + request.host_with_port
     end