6 files changed, 100 insertions, 6 deletions

diff --git a/lib/arel.rb b/lib/arel.rb
index a805cf60fa..afab11cd91 100644
--- a/lib/arel.rb
+++ b/lib/arel.rb
@@ -1,3 +1,6 @@
 require 'arel/version'
 require 'arel/table'
+require 'arel/attributes'
+
+# below is deprecated
 require 'arel/sql/engine'
diff --git a/lib/arel/attributes.rb b/lib/arel/attributes.rb
new file mode 100644
index 0000000000..a7fb00293b
--- /dev/null
+++ b/lib/arel/attributes.rb
@@ -0,0 +1,20 @@
+require 'arel/attributes/attribute'
+
+module Arel
+  module Attributes
+    ###
+    # Factory method to wrap a raw database +column+ to an Arel Attribute.
+    def self.for column
+      case column.type
+      when :string, :text, :binary             then String
+      when :integer                            then Integer
+      when :float                              then Float
+      when :decimal                            then Decimal
+      when :date, :datetime, :timestamp, :time then Time
+      when :boolean                            then Boolean
+      else
+        raise NotImplementedError, "Column type `#{column.type}` is not currently handled"
+      end
+    end
+  end
+end
diff --git a/lib/arel/attributes/attribute.rb b/lib/arel/attributes/attribute.rb
new file mode 100644
index 0000000000..b83a32bee7
--- /dev/null
+++ b/lib/arel/attributes/attribute.rb
@@ -0,0 +1,13 @@
+module Arel
+  module Attributes
+    class Attribute < Struct.new :relation, :name, :column
+    end
+
+    class String < Attribute; end
+    class Time < Attribute; end
+    class Boolean < Attribute; end
+    class Decimal < Attribute; end
+    class Float < Attribute; end
+    class Integer < Attribute; end
+  end
+end
diff --git a/lib/arel/table.rb b/lib/arel/table.rb
index a4ae9bd18d..78b3ea9933 100644
--- a/lib/arel/table.rb
+++ b/lib/arel/table.rb
@@ -3,13 +3,20 @@ module Arel
     @engine = nil
     class << self; attr_accessor :engine; end
 
-    def initialize table_name, engine = Table.engine
-      @table_name = table_name
-      @engine     = engine
+    def initialize name, engine = Table.engine
+      @name   = name
+      @engine = engine
     end
 
-    def [] attribute
-      raise attribute
+    def columns
+      @engine.connection.columns(@name, "#{@name} Columns").map do |column|
+        Attributes.for(column).new self, column.name, column
+      end
+    end
+
+    def [] name
+      name = name.to_s
+      columns.find { |column| column.name == name }
     end
   end
 end
diff --git a/spec/arel/attributes_spec.rb b/spec/arel/attributes_spec.rb
new file mode 100644
index 0000000000..8b437dff9b
--- /dev/null
+++ b/spec/arel/attributes_spec.rb
@@ -0,0 +1,41 @@
+require 'spec_helper'
+
+module Arel
+  describe 'Attributes' do
+    describe 'for' do
+      it 'returns the correct constant for strings' do
+        [:string, :text, :binary].each do |type|
+          column = Struct.new(:type).new type
+          Attributes.for(column).should == Attributes::String
+        end
+      end
+
+      it 'returns the correct constant for ints' do
+        column = Struct.new(:type).new :integer
+        Attributes.for(column).should == Attributes::Integer
+      end
+
+      it 'returns the correct constant for floats' do
+        column = Struct.new(:type).new :float
+        Attributes.for(column).should == Attributes::Float
+      end
+
+      it 'returns the correct constant for decimals' do
+        column = Struct.new(:type).new :decimal
+        Attributes.for(column).should == Attributes::Decimal
+      end
+
+      it 'returns the correct constant for boolean' do
+        column = Struct.new(:type).new :boolean
+        Attributes.for(column).should == Attributes::Boolean
+      end
+
+      it 'returns the correct constant for time' do
+        [:date, :datetime, :timestamp, :time].each do |type|
+          column = Struct.new(:type).new type
+          Attributes.for(column).should == Attributes::Time
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/table_spec.rb b/spec/arel/table_spec.rb
index 20c962c26a..c52a111489 100644
--- a/spec/arel/table_spec.rb
+++ b/spec/arel/table_spec.rb
@@ -6,14 +6,24 @@ module Arel
       @relation = Table.new(:users)
     end
 
+    describe 'columns' do
+      it 'returns a list of columns' do
+        columns = @relation.columns
+        columns.length.should == 2
+        columns.map { |x| x.name }.sort.should == %w{ name id }.sort
+      end
+    end
+
     describe '[]' do
       describe 'when given a', Symbol do
         it "manufactures an attribute if the symbol names an attribute within the relation" do
           column = @relation[:id]
-          #.should == Attributes::Integer.new(@relation, :id)
+          column.name.should == 'id'
+          column.should be_kind_of Attributes::Integer
         end
       end
 
+      ### FIXME: this seems like a bad requirement.
       #describe 'when given an', Attribute do
       #  it "returns the attribute if the attribute is within the relation" do
       #    @relation[@relation[:id]].should == @relation[:id]