lib/chronicle/etl/transformers/transformer.rb in chronicle-etl-0.1.4 vs lib/chronicle/etl/transformers/transformer.rb in chronicle-etl-0.2.0

@@ -1,16 +1,32 @@
 module Chronicle
-  module Etl
+  module ETL
+    # Abstract class representing an Transformer for an ETL job
     class Transformer
-      extend Chronicle::Etl::Catalog
+      extend Chronicle::ETL::Catalog
 
+      # Construct a new instance of this transformer. Options are passed in from a Runner
+      # == Paramters:
+      # options::
+      #   Options for configuring this Transformer
       def initialize(options = {})
         @options = options
       end
 
+      # The main entrypoint for transforming a record. Called by a Runner on each extracted record
       def transform data
         raise NotImplementedError
       end
+
+      # The domain or provider-specific id of the record this transformer is working on.
+      # Used for building a cursor so an extractor doesn't have to start from the beginning of a
+      # data source from the beginning.
+      def id; end
+
+      # The domain or provider-specific timestamp of the record this transformer is working on.
+      # Used for building a cursor so an extractor doesn't have to start from the beginning of a
+      # data source from the beginning.
+      def timestamp; end
     end
   end
 end
 
 require_relative 'json_transformer'