Attributes should be typed

5 files changed, 52 insertions, 12 deletions

diff --git a/lib/arel/engines/memory/relations/array.rb b/lib/arel/engines/memory/relations/array.rb
index 5e7c0a4ab1..577e327b19 100644
--- a/lib/arel/engines/memory/relations/array.rb
+++ b/lib/arel/engines/memory/relations/array.rb
@@ -1,16 +1,21 @@
 module Arel
   class Array < Relation
-    attributes :array,  :attribute_names
+    attributes :array,  :attribute_names_and_types
     include Recursion::BaseCase
     deriving :==, :initialize
 
+    def initialize(array, attribute_names_and_types)
+      @array, @attribute_names_and_types = array, attribute_names_and_types
+    end
+
     def engine
       @engine ||= Memory::Engine.new
     end
 
     def attributes
-      @attributes ||= @attribute_names.collect do |name|
-        name.to_attribute(self)
+      @attributes ||= @attribute_names_and_types.collect do |attribute, type|
+        attribute = type.new(self, attribute) if Symbol === attribute
+        attribute
       end
     end
 
diff --git a/lib/arel/engines/sql.rb b/lib/arel/engines/sql.rb
index dc40428b77..a7721eb909 100644
--- a/lib/arel/engines/sql.rb
+++ b/lib/arel/engines/sql.rb
@@ -1,3 +1,4 @@
+require 'arel/engines/sql/attributes'
 require 'arel/engines/sql/engine'
 require 'arel/engines/sql/relations'
 require 'arel/engines/sql/primitives'
diff --git a/lib/arel/engines/sql/attributes.rb b/lib/arel/engines/sql/attributes.rb
new file mode 100644
index 0000000000..2d315d53fc
--- /dev/null
+++ b/lib/arel/engines/sql/attributes.rb
@@ -0,0 +1,40 @@
+module Arel
+  module Sql
+    module Attributes
+      def self.for(column)
+        case column.type
+        when :string    then String
+        when :text      then String
+        when :integer   then Integer
+        when :float     then Float
+        when :decimal   then Decimal
+        when :date      then Time
+        when :datetime  then Time
+        when :timestamp then Time
+        when :time      then Time
+        when :binary    then String
+        when :boolean   then Boolean
+        else
+          raise NotImplementedError, "Column type `#{column.type}` is not currently handled"
+        end
+      end
+
+      def initialize(column, *args)
+        @column = column
+        super(*args)
+      end
+
+      def type_cast(value)
+        @column.type_cast(value)
+      end
+
+      %w(Boolean Decimal Float Integer String Time).each do |klass|
+        class_eval <<-R
+          class #{klass} < Arel::Attributes::#{klass}
+            include Attributes
+          end
+        R
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/arel/engines/sql/primitives.rb b/lib/arel/engines/sql/primitives.rb
index 6cce46a441..666579331a 100644
--- a/lib/arel/engines/sql/primitives.rb
+++ b/lib/arel/engines/sql/primitives.rb
@@ -16,10 +16,6 @@ module Arel
       original_relation.column_for(self)
     end
 
-    def type_cast(value)
-      root.relation.format(self, value)
-    end
-
     def format(object)
       object.to_sql(Sql::Attribute.new(self))
     end
diff --git a/lib/arel/engines/sql/relations/table.rb b/lib/arel/engines/sql/relations/table.rb
index d10b761ea3..c0d3386463 100644
--- a/lib/arel/engines/sql/relations/table.rb
+++ b/lib/arel/engines/sql/relations/table.rb
@@ -41,7 +41,9 @@ module Arel
     def attributes
       return @attributes if defined?(@attributes)
       if table_exists?
-        @attributes = columns.collect { |column| Attribute.new(self, column.name.to_sym) }
+        @attributes = columns.collect do |column|
+          Sql::Attributes.for(column).new(column, self, column.name.to_sym)
+        end
       else
         []
       end
@@ -55,10 +57,6 @@ module Arel
       @hash ||= :name.hash
     end
 
-    def format(attribute, value)
-      attribute.column.type_cast(value)
-    end
-
     def column_for(attribute)
       has_attribute?(attribute) and columns.detect { |c| c.name == attribute.name.to_s }
     end