ActiveModel support for the :include serialization option

This commit moves support for the :include serialization option for
serializing associated objects out of ActiveRecord in into ActiveModel.
The following methods support the :include option:

  * serializable_hash
  * to_json
  * to_xml

Instances must respond to methods named by the values of the :includes
array (or keys of the :includes hash). If an association method returns
an object that is_a?(Enumerable) (which AR has_many associations do), it
is assumed to be a collection association, and its elements must respond
to :serializable_hash. Otherwise it must respond to :serializable_hash
itself.

While here, fix #858, XmlSerializer should not singularize already
singular association names.

1 files changed, 0 insertions, 42 deletions

diff --git a/activerecord/lib/active_record/serializers/xml_serializer.rb b/activerecord/lib/active_record/serializers/xml_serializer.rb
index 67f6c7833c..cbfa1ad609 100644
--- a/activerecord/lib/active_record/serializers/xml_serializer.rb
+++ b/activerecord/lib/active_record/serializers/xml_serializer.rb
@@ -182,48 +182,6 @@ module ActiveRecord #:nodoc:
       options[:except] |= Array.wrap(@serializable.class.inheritance_column)
     end
 
-    def add_extra_behavior
-      add_includes
-    end
-
-    def add_includes
-      procs = options.delete(:procs)
-      @serializable.send(:serializable_add_includes, options) do |association, records, opts|
-        add_associations(association, records, opts)
-      end
-      options[:procs] = procs
-    end
-
-    # TODO This can likely be cleaned up to simple use ActiveSupport::XmlMini.to_tag as well.
-    def add_associations(association, records, opts)
-      association_name = association.to_s.singularize
-      merged_options   = options.merge(opts).merge!(:root => association_name, :skip_instruct => true)
-
-      if records.is_a?(Enumerable)
-        tag  = ActiveSupport::XmlMini.rename_key(association.to_s, options)
-        type = options[:skip_types] ? { } : {:type => "array"}
-
-        if records.empty?
-          @builder.tag!(tag, type)
-        else
-          @builder.tag!(tag, type) do
-            records.each do |record|
-              if options[:skip_types]
-                record_type = {}
-              else
-                record_class = (record.class.to_s.underscore == association_name) ? nil : record.class.name
-                record_type = {:type => record_class}
-              end
-
-              record.to_xml merged_options.merge(record_type)
-            end
-          end
-        end
-      else
-        records.to_xml(merged_options)
-      end
-    end
-
     class Attribute < ActiveModel::Serializers::Xml::Serializer::Attribute #:nodoc:
       def compute_type
         klass = @serializable.class