1 files changed, 56 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
new file mode 100644
index 0000000000..9d6111b51e
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
@@ -0,0 +1,56 @@
+module ActiveRecord
+  module ConnectionAdapters # :nodoc:
+    # The goal of this module is to move Adapter specific column
+    # definitions to the Adapter instead of having it in the schema
+    # dumper itself. This code represents the normal case.
+    # We can then redefine how certain data types may be handled in the schema dumper on the 
+    # Adapter level by over-writing this code inside the database spececific adapters
+    module ColumnDumper
+      def column_spec(column, types)
+        spec = prepare_column_options(column, types)
+        (spec.keys - [:name, :type]).each{ |k| spec[k].insert(0, "#{k.to_s}: ")}
+        spec
+      end
+
+      # This can be overridden on a Adapter level basis to support other
+      # extended datatypes (Example: Adding an array option in the
+      # PostgreSQLAdapter)
+      def prepare_column_options(column, types)
+        spec = {}
+        spec[:name]      = column.name.inspect
+
+        # AR has an optimization which handles zero-scale decimals as integers. This
+        # code ensures that the dumper still dumps the column as a decimal.
+        spec[:type]      = if column.type == :integer && /^(numeric|decimal)/ =~ column.sql_type
+                             'decimal'
+                           else
+                             column.type.to_s
+                           end
+        spec[:limit]     = column.limit.inspect if column.limit != types[column.type][:limit] && spec[:type] != 'decimal'
+        spec[:precision] = column.precision.inspect if column.precision
+        spec[:scale]     = column.scale.inspect if column.scale
+        spec[:null]      = 'false' unless column.null
+        spec[:default]   = default_string(column.default) if column.has_default?
+        spec
+      end
+
+      # Lists the valid migration options
+      def migration_keys
+        [:name, :limit, :precision, :scale, :default, :null]
+      end
+
+      private
+
+        def default_string(value)
+          case value
+          when BigDecimal
+            value.to_s
+          when Date, DateTime, Time
+            "'#{value.to_s(:db)}'"
+          else
+            value.inspect
+          end
+        end
+    end
+  end
+end