extracts cached tsvector to concern

app/models/concerns/search_cache.rb

@@ -0,0 +1,25 @@
+module SearchCache
+  extend ActiveSupport::Concern
+
+  included do
+    after_save :calculate_tsvector
+  end
+
+  def calculate_tsvector
+    ActiveRecord::Base.connection.execute("
+      UPDATE proposals SET tsv = (to_tsvector('spanish', #{fields_to_sql})) WHERE id = #{self.id}")
+  end
+
+  def fields_to_sql
+    fields.collect { |field| "coalesce(#{field},'')" }.join(" || ' ' || ")
+  end
+
+  def fields
+    searchable_fields << tags_to_sql
+  end
+
+  def tags_to_sql
+    "\'#{tag_list.join(' ')}\'"
+  end
+
+end