From 7a10201d3acf7cc3a267f4d215214cf5dedca0a4 Mon Sep 17 00:00:00 2001
From: James Sanders <sanderjd@gmail.com>
Date: Wed, 19 Aug 2009 10:28:12 -0600
Subject: [PATCH] Add skip_nils to xml serializer

---
 .../active_record/serializers/xml_serializer.rb    |   11 ++++---
 activerecord/test/cases/xml_serialization_test.rb  |   32 +++++++++++++++++--
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/activerecord/lib/active_record/serializers/xml_serializer.rb b/activerecord/lib/active_record/serializers/xml_serializer.rb
index 9bf1193..1526caf 100644
--- a/activerecord/lib/active_record/serializers/xml_serializer.rb
+++ b/activerecord/lib/active_record/serializers/xml_serializer.rb
@@ -18,17 +18,18 @@ module ActiveRecord #:nodoc:
     #     <written-on type="datetime">2003-07-16T09:28:00+1200</written-on>
     #     <content>Have a nice day</content>
     #     <author-email-address>david@loudthinking.com</author-email-address>
-    #     <parent-id></parent-id>
+    #     <parent-id nil="true"></parent-id>
     #     <last-read type="date">2004-04-15</last-read>
     #   </topic>
     #
     # This behavior can be controlled with <tt>:only</tt>, <tt>:except</tt>,
-    # <tt>:skip_instruct</tt>, <tt>:skip_types</tt>, <tt>:dasherize</tt> and <tt>:camelize</tt> .
+    # <tt>:skip_instruct</tt>, <tt>:skip_types</tt>, <tt>:skip_nils</tt>, <tt>:dasherize</tt> and <tt>:camelize</tt> .
     # The <tt>:only</tt> and <tt>:except</tt> options are the same as for the
     # +attributes+ method. The default is to dasherize all column names, but you
     # can disable this setting <tt>:dasherize</tt> to +false+. Setting <tt>:camelize</tt>
     # to +true+ will camelize all column names - this also overrides <tt>:dasherize</tt>.
     # To not have the column type included in the XML output set <tt>:skip_types</tt> to +true+.
+    # To not list nil="true" for nil attributes set <tt>:skip_nils</tt> to +true+.
     #
     # For instance:
     #
@@ -224,7 +225,7 @@ module ActiveRecord #:nodoc:
       builder.tag!(
         reformat_name(attribute.name),
         attribute.value.to_s,
-        attribute.decorations(!options[:skip_types])
+        attribute.decorations(!options[:skip_types], !options[:skip_nils])
       )
     end
 
@@ -300,7 +301,7 @@ module ActiveRecord #:nodoc:
         ![ :binary, :date, :datetime, :boolean, :float, :integer ].include?(type)
       end
 
-      def decorations(include_types = true)
+      def decorations(include_types = true, include_nils = true)
         decorations = {}
 
         if type == :binary
@@ -311,7 +312,7 @@ module ActiveRecord #:nodoc:
           decorations[:type] = type
         end
 
-        if value.nil?
+        if include_nils && value.nil?
           decorations[:nil] = true
         end
 
diff --git a/activerecord/test/cases/xml_serialization_test.rb b/activerecord/test/cases/xml_serialization_test.rb
index d8d952b..cc9b220 100644
--- a/activerecord/test/cases/xml_serialization_test.rb
+++ b/activerecord/test/cases/xml_serialization_test.rb
@@ -86,11 +86,14 @@ end
 
 class NilXmlSerializationTest < ActiveRecord::TestCase
   def setup
-    @xml = Contact.new.to_xml(:root => 'xml_contact')
+    contact = Contact.new
+    @xml = contact.to_xml(:root => 'xml_contact')
+    @xml_without_nils = contact.to_xml(:root => 'xml_contact', :skip_nils => true)
   end
 
   def test_should_serialize_string
-    assert_match %r{<name nil="true"></name>},     @xml
+    assert_match %r{<name nil="true"></name>}, @xml
+    assert_match %r{<name></name>}, @xml_without_nils
   end
 
   def test_should_serialize_integer
@@ -98,6 +101,11 @@ class NilXmlSerializationTest < ActiveRecord::TestCase
     attributes = $1
     assert_match %r{nil="true"}, attributes
     assert_match %r{type="integer"}, attributes
+
+    assert %r{<age (.*)></age>}.match(@xml_without_nils)
+    attributes = $1
+    assert_no_match %r{nil="true"}, attributes
+    assert_match %r{type="integer"}, attributes
   end
 
   def test_should_serialize_binary
@@ -106,6 +114,12 @@ class NilXmlSerializationTest < ActiveRecord::TestCase
     assert_match %r{type="binary"}, attributes
     assert_match %r{encoding="base64"}, attributes
     assert_match %r{nil="true"}, attributes
+
+    assert %r{<avatar (.*)></avatar>}.match(@xml_without_nils)
+    attributes = $1
+    assert_match %r{type="binary"}, attributes
+    assert_match %r{encoding="base64"}, attributes
+    assert_no_match %r{nil="true"}, attributes
   end
 
   def test_should_serialize_datetime
@@ -113,13 +127,18 @@ class NilXmlSerializationTest < ActiveRecord::TestCase
     attributes = $1
     assert_match %r{nil="true"}, attributes
     assert_match %r{type="datetime"}, attributes
+
+    assert %r{<created-at (.*)></created-at>}.match(@xml_without_nils)
+    attributes = $1
+    assert_no_match %r{nil="true"}, attributes
+    assert_match %r{type="datetime"}, attributes
   end
 
   def test_should_serialize_boolean
-    assert %r{<awesome (.*)></awesome>}.match(@xml)
+    assert %r{<awesome (.*)></awesome>}.match(@xml_without_nils)
     attributes = $1
     assert_match %r{type="boolean"}, attributes
-    assert_match %r{nil="true"}, attributes
+    assert_no_match %r{nil="true"}, attributes
   end
 
   def test_should_serialize_yaml
@@ -127,6 +146,11 @@ class NilXmlSerializationTest < ActiveRecord::TestCase
     attributes = $1
     assert_match %r{type="yaml"}, attributes
     assert_match %r{nil="true"}, attributes
+
+    assert %r{<preferences(.*)></preferences>}.match(@xml_without_nils)
+    attributes = $1
+    assert_match %r{type="yaml"}, attributes
+    assert_no_match %r{nil="true"}, attributes
   end
 end
 
-- 
1.6.3.3