Make search cache order aware & accept values instead of column names

app/models/concerns/search_cache.rb

@@ -7,19 +7,20 @@ module SearchCache
 
   def calculate_tsvector
     ActiveRecord::Base.connection.execute("
-      UPDATE proposals SET tsv = (to_tsvector('spanish', #{fields_to_sql})) WHERE id = #{self.id}")
+      UPDATE proposals SET tsv = (#{searchable_values_sql}) WHERE id = #{self.id}")
   end
 
-  def fields_to_sql
-    fields.collect { |field| "coalesce(#{field},'')" }.join(" || ' ' || ")
+  private
+
+  def searchable_values_sql
+    cx = ActiveRecord::Base.connection
+    arr = []
+    searchable_values.each do |val, weight|
+      if val.present?
+        arr << "setweight(to_tsvector('spanish', coalesce(#{cx.quote(val)}, '')), #{cx.quote(weight)})"
+      end
+    end
+    arr.join(" || ")
   end
 
-  def fields
-    searchable_fields << tags_to_sql
-  end
-
-  def tags_to_sql
-    "\'#{tag_list.join(' ')}\'"
-  end
-
-end
+end

app/models/proposal.rb

@@ -58,8 +58,15 @@ class Proposal < ActiveRecord::Base
     order_within_rank: "proposals.created_at DESC"
   }
 
-  def searchable_fields
-    %w(title question summary description)
+  def searchable_values
+    values = {
+      title => 'A',
+      question => 'B',
+      summary => 'C',
+      description => 'D'
+    }
+    tag_list.each{ |tag| values[tag] = 'D' }
+    values
   end
 
   def description