Patch to ActiveModel's (and ActiveRecord, by association) XML serialization: If two parameters are present in Procs supplied to to_xml's :procs option, the model being serialized will be passed as the second argument [#2373 state:resolved]

Signed-off-by: Joshua Peek <josh@joshpeek.com>

2 files changed, 21 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/serializers/xml_serializer.rb b/activerecord/lib/active_record/serializers/xml_serializer.rb
index 253fa03785..4e172bd2b6 100644
--- a/activerecord/lib/active_record/serializers/xml_serializer.rb
+++ b/activerecord/lib/active_record/serializers/xml_serializer.rb
@@ -71,6 +71,21 @@ module ActiveRecord #:nodoc:
     #     </account>
     #   </firm>
     #
+    # Additionally, the record being serialized will be passed to a Proc's second
+    # parameter.  This allows for ad hoc additions to the resultant document that
+    # incorporate the context of the record being serialized. And by leveraging the
+    # closure created by a Proc, to_xml can be used to add elements that normally fall
+    # outside of the scope of the model -- for example, generating and appending URLs
+    # associated with models.
+    # 
+    #   proc = Proc.new { |options, record| options[:builder].tag!('name-reverse', record.name.reverse) }
+    #   firm.to_xml :procs => [ proc ]
+    #
+    #   <firm>
+    #     # ... normal attributes as shown above ...
+    #     <name-reverse>slangis73</name-reverse>
+    #   </firm>
+    #
     # To include deeper levels of associations pass a hash like this:
     #
     #   firm.to_xml :include => {:account => {}, :clients => {:include => :address}}
diff --git a/activerecord/test/cases/xml_serialization_test.rb b/activerecord/test/cases/xml_serialization_test.rb
index b49997669e..e1ad5c1685 100644
--- a/activerecord/test/cases/xml_serialization_test.rb
+++ b/activerecord/test/cases/xml_serialization_test.rb
@@ -174,6 +174,12 @@ class DatabaseConnectedXmlSerializationTest < ActiveRecord::TestCase
     assert_match %r{<nationality>Danish</nationality>}, xml
   end
 
+  def test_dual_arity_procs_are_called_on_object
+    proc = Proc.new { |options, record| options[:builder].tag!('name-reverse', record.name.reverse) }
+    xml = authors(:david).to_xml(:procs => [ proc ])
+    assert_match %r{<name-reverse>divaD</name-reverse>}, xml
+  end
+
   def test_top_level_procs_arent_applied_to_associations
     author_proc = Proc.new { |options| options[:builder].tag!('nationality', 'Danish') }
     xml = authors(:david).to_xml(:procs => [ author_proc ], :include => :posts, :indent => 2)