destination.rb in activewarehouse-etl-0.4.0

- old
+ new

@@ -1,10 +1,10 @@
 module ETL #:nodoc:
   module Control #:nodoc:
     class Destination
       attr_reader :control, :configuration, :mapping
-      attr_accessor :buffer_size, :current_row
+      attr_accessor :buffer_size, :current_row, :unique
       
       class << self
         def class_for_name(name)
           ETL::Control.const_get("#{name.to_s.classify}Destination")
         end
@@ -55,9 +55,44 @@
           else
             order << item
           end
         end
         order
+      end
+      
+      # Return true if the row is allowed. The row will not be allowed if the :unique option is specified
+      # in the configuration and the compound key already exists
+      def row_allowed?(row)
+        if unique
+          key = (unique.collect { |k| row[k] }).join('|')
+          return false if compound_key_constraints[key]
+          compound_key_constraints[key] = 1
+        end
+        return true
+      end
+      
+      # Get a hash of compound key contraints. This is used to determine if a row can be written when the
+      # unique option is specified
+      def compound_key_constraints
+        @compound_key_constraints ||= {}
+      end
+      
+      # Add any virtual fields to the row
+      def add_virtuals!(row)
+        if mapping[:virtual]
+          mapping[:virtual].each do |key,value|
+            # Engine.logger.debug "Mapping virtual #{key}/#{value} for row #{row}"
+            case value
+            when Symbol
+              generators[key] ||= ETL::Generator::Generator.class_for_name(value).new
+              row[key] = generators[key].next
+            when Proc
+              row[key] = value.call(row)
+            else
+              row[key] = value
+            end
+          end
+        end
       end
     end
   end
 end
 
\ No newline at end of file