1 files changed, 57 insertions, 33 deletions

diff --git a/activemodel/lib/active_model/serializers/xml.rb b/activemodel/lib/active_model/serializers/xml.rb
index eb3975f86b..d61d9d7119 100644
--- a/activemodel/lib/active_model/serializers/xml.rb
+++ b/activemodel/lib/active_model/serializers/xml.rb
@@ -15,10 +15,10 @@ module ActiveModel
         class Attribute #:nodoc:
           attr_reader :name, :value, :type
 
-          def initialize(name, serializable, raw_value=nil)
+          def initialize(name, serializable, value)
             @name, @serializable = name, serializable
-            raw_value = raw_value.in_time_zone if raw_value.respond_to?(:in_time_zone)
-            @value = raw_value || @serializable.send(name)
+            value  = value.in_time_zone if value.respond_to?(:in_time_zone)
+            @value = value
             @type  = compute_type
           end
 
@@ -49,40 +49,24 @@ module ActiveModel
         def initialize(serializable, options = nil)
           @serializable = serializable
           @options = options ? options.dup : {}
-
-          @options[:only] = Array.wrap(@options[:only]).map { |n| n.to_s }
-          @options[:except] = Array.wrap(@options[:except]).map { |n| n.to_s }
         end
 
-        # To replicate the behavior in ActiveRecord#attributes, <tt>:except</tt>
-        # takes precedence over <tt>:only</tt>.  If <tt>:only</tt> is not set
-        # for a N level model but is set for the N+1 level models,
-        # then because <tt>:except</tt> is set to a default value, the second
-        # level model can have both <tt>:except</tt> and <tt>:only</tt> set.  So if
-        # <tt>:only</tt> is set, always delete <tt>:except</tt>.
-        def attributes_hash
-          attributes = @serializable.attributes
-          if options[:only].any?
-            attributes.slice(*options[:only])
-          elsif options[:except].any?
-            attributes.except(*options[:except])
-          else
-            attributes
-          end
+        def serializable_hash
+          @serializable.serializable_hash(@options.except(:include))
         end
 
-        def serializable_attributes
-          attributes_hash.map do |name, value|
-            self.class::Attribute.new(name, @serializable, value)
+        def serializable_collection
+          methods = Array.wrap(options[:methods]).map(&:to_s)
+          serializable_hash.map do |name, value|
+            name = name.to_s
+            if methods.include?(name)
+              self.class::MethodAttribute.new(name, @serializable, value)
+            else
+              self.class::Attribute.new(name, @serializable, value)
+            end
           end
         end
 
-        def serializable_methods
-          Array.wrap(options[:methods]).map do |name|
-            self.class::MethodAttribute.new(name.to_s, @serializable) if @serializable.respond_to?(name.to_s)
-          end.compact
-        end
-
         def serialize
           require 'builder' unless defined? ::Builder
 
@@ -101,6 +85,7 @@ module ActiveModel
 
           @builder.tag!(*args) do
             add_attributes_and_methods
+            add_includes
             add_extra_behavior
             add_procs
             yield @builder if block_given?
@@ -113,13 +98,52 @@ module ActiveModel
         end
 
         def add_attributes_and_methods
-          (serializable_attributes + serializable_methods).each do |attribute|
+          serializable_collection.each do |attribute|
             key = ActiveSupport::XmlMini.rename_key(attribute.name, options)
             ActiveSupport::XmlMini.to_tag(key, attribute.value,
               options.merge(attribute.decorations))
           end
         end
 
+        def add_includes
+          @serializable.send(:serializable_add_includes, options) do |association, records, opts|
+            add_associations(association, records, opts)
+          end
+        end
+
+        # TODO This can likely be cleaned up to simple use ActiveSupport::XmlMini.to_tag as well.
+        def add_associations(association, records, opts)
+          merged_options = opts.merge(options.slice(:builder, :indent))
+          merged_options[:skip_instruct] = true
+
+          if records.is_a?(Enumerable)
+            tag  = ActiveSupport::XmlMini.rename_key(association.to_s, options)
+            type = options[:skip_types] ? { } : {:type => "array"}
+            association_name = association.to_s.singularize
+            merged_options[:root] = association_name
+
+            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
+            merged_options[:root] = association.to_s
+            records.to_xml(merged_options)
+          end
+        end
+
         def add_procs
           if procs = options.delete(:procs)
             Array.wrap(procs).each do |proc|
@@ -139,8 +163,8 @@ module ActiveModel
       # Without any +options+, the returned XML string will include all the model's
       # attributes. For example:
       #
-      #   konata = User.find(1)
-      #   konata.to_xml
+      #   user = User.find(1)
+      #   user.to_xml
       #
       #   <?xml version="1.0" encoding="UTF-8"?>
       #   <user>