From 85882d1b26b033afb2643865afe6410673949d32 Mon Sep 17 00:00:00 2001
From: Arthur Taylor <arthur@aupeo.com>
Date: Thu, 28 Apr 2011 10:11:50 +0200
Subject: [PATCH] Add support for ordering on expressions

Conflicts:

	lib/arel.rb
	lib/arel/attributes/attribute.rb
	lib/arel/nodes/infix_operation.rb
	lib/arel/nodes/named_function.rb

Conflicts:

	lib/arel.rb
	lib/arel/attributes/attribute.rb
---
 lib/arel.rb                      |  1 +
 lib/arel/attributes/attribute.rb |  1 +
 lib/arel/expression.rb           |  1 +
 lib/arel/nodes/sql_literal.rb    |  1 +
 lib/arel/order_predications.rb   | 13 +++++++++++++
 lib/arel/predications.rb         |  9 +--------
 test/test_select_manager.rb      | 23 +++++++++++++++++++++++
 7 files changed, 41 insertions(+), 8 deletions(-)
 create mode 100644 lib/arel/order_predications.rb

diff --git a/lib/arel.rb b/lib/arel.rb
index de429f532e..bc599514e2 100644
--- a/lib/arel.rb
+++ b/lib/arel.rb
@@ -4,6 +4,7 @@ require 'arel/factory_methods'
 require 'arel/expressions'
 require 'arel/predications'
 require 'arel/math'
+require 'arel/order_predications'
 require 'arel/table'
 require 'arel/attributes'
 require 'arel/compatibility/wheres'
diff --git a/lib/arel/attributes/attribute.rb b/lib/arel/attributes/attribute.rb
index 240f224d8c..b9fd8da67e 100644
--- a/lib/arel/attributes/attribute.rb
+++ b/lib/arel/attributes/attribute.rb
@@ -3,6 +3,7 @@ module Arel
     class Attribute < Struct.new :relation, :name
       include Arel::Expressions
       include Arel::Predications
+      include Arel::OrderPredications
       include Arel::Math
 
       ###
diff --git a/lib/arel/expression.rb b/lib/arel/expression.rb
index eb2c21bfd3..3884d6ede6 100644
--- a/lib/arel/expression.rb
+++ b/lib/arel/expression.rb
@@ -1,4 +1,5 @@
 module Arel
   module Expression
+    include Arel::OrderPredications
   end
 end
diff --git a/lib/arel/nodes/sql_literal.rb b/lib/arel/nodes/sql_literal.rb
index c76a16daf1..ad0bb00484 100644
--- a/lib/arel/nodes/sql_literal.rb
+++ b/lib/arel/nodes/sql_literal.rb
@@ -3,6 +3,7 @@ module Arel
     class SqlLiteral < String
       include Arel::Expressions
       include Arel::Predications
+      include Arel::OrderPredications
     end
   end
 end
diff --git a/lib/arel/order_predications.rb b/lib/arel/order_predications.rb
new file mode 100644
index 0000000000..af163c9454
--- /dev/null
+++ b/lib/arel/order_predications.rb
@@ -0,0 +1,13 @@
+module Arel
+  module OrderPredications
+
+    def asc
+      Nodes::Ordering.new self, :asc
+    end
+
+    def desc
+      Nodes::Ordering.new self, :desc
+    end
+
+  end
+end
diff --git a/lib/arel/predications.rb b/lib/arel/predications.rb
index 7e2425e45f..08cbf16d9d 100644
--- a/lib/arel/predications.rb
+++ b/lib/arel/predications.rb
@@ -1,5 +1,6 @@
 module Arel
   module Predications
+
     def as other
       Nodes::As.new self, Nodes::SqlLiteral.new(other)
     end
@@ -152,14 +153,6 @@ module Arel
       grouping_all :lteq, others
     end
 
-    def asc
-      Nodes::Ordering.new self, :asc
-    end
-
-    def desc
-      Nodes::Ordering.new self, :desc
-    end
-
     private
 
     def grouping_any method_id, others
diff --git a/test/test_select_manager.rb b/test/test_select_manager.rb
index 8de1520b6f..29d317e16a 100644
--- a/test/test_select_manager.rb
+++ b/test/test_select_manager.rb
@@ -484,6 +484,29 @@ module Arel
         manager = Arel::SelectManager.new Table.engine
         manager.order(table[:id]).must_equal manager
       end
+
+      it 'has order attributes' do
+        table   = Table.new :users
+        manager = Arel::SelectManager.new Table.engine
+        manager.project SqlLiteral.new '*'
+        manager.from table
+        manager.order table[:id].desc
+        manager.to_sql.must_be_like %{
+          SELECT * FROM "users" ORDER BY "users"."id" DESC
+        }
+      end
+
+      it 'has order attributes for expressions' do
+        table   = Table.new :users
+        manager = Arel::SelectManager.new Table.engine
+        manager.project SqlLiteral.new '*'
+        manager.from table
+        manager.order table[:id].count.desc
+        manager.to_sql.must_be_like %{
+          SELECT * FROM "users" ORDER BY COUNT("users"."id") DESC
+        }
+      end
+
     end
 
     describe 'on' do