custom_field drilldown fix now without introducing new bugs. nice

git-svn-id: https://dev.finn.de/svn/cockpit/branches/reporting_merge@1830 7926756e-e54e-46e6-9721-ed318f58905e

app/models/cost_query.rb

@@ -29,7 +29,7 @@ class CostQuery < ActiveRecord::Base
   end
 
   def add_chain(type, name, options)
-    chain type.const_get(name.to_s.camelcase.singularize), options
+    chain type.const_get(name.to_s.camelcase), options
     @transformer, @table, @depths, @walker = nil, nil, nil, nil
     self
   end

app/models/cost_query/custom_field_mixin.rb

@@ -38,10 +38,14 @@ module CostQuery::CustomFieldMixin
     @on_prepare
   end
 
+  def table_name
+    @class_name.demodulize.underscore.tableize.singularize
+  end
+
   def prepare(field, class_name)
     @custom_field = field
     label field.name
-    table_name(class_name.demodulize.underscore.tableize)
+    @class_name = class_name
     dont_inherit :group_fields
     db_field table_name
     join_table (<<-SQL % [CustomValue.table_name, table_name, field.id, field.name, SQL_TYPES[field.field_format]]).gsub(/^    /, "")