Added :include option to to_json (closes #9677) [chuyeow]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7663 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 45 insertions, 6 deletions

diff --git a/activerecord/lib/active_record/serialization.rb b/activerecord/lib/active_record/serialization.rb
index f10d1b3b7e..2c8210a299 100644
--- a/activerecord/lib/active_record/serialization.rb
+++ b/activerecord/lib/active_record/serialization.rb
@@ -2,7 +2,7 @@ module ActiveRecord #:nodoc:
   module Serialization
     class Serializer #:nodoc:
       attr_reader :options
-    
+
       def initialize(record, options = {})
         @record, @options = record, options.dup
       end
@@ -23,31 +23,70 @@ module ActiveRecord #:nodoc:
           options[:except] = Array(options[:except]) | Array(@record.class.inheritance_column)
           attribute_names = attribute_names - options[:except].collect { |n| n.to_s }
         end
-      
+
         attribute_names
       end
 
       def serializable_method_names
         Array(options[:methods]).inject([]) do |method_attributes, name|
-          method_attributes << :name if @record.respond_to?(name.to_s)
+          method_attributes << name if @record.respond_to?(name.to_s)
           method_attributes
         end
       end
-      
+
       def serializable_names
         serializable_attribute_names + serializable_method_names
       end
 
+      # Add associations specified via the :includes option.
+      # Expects a block that takes as arguments:
+      #   +association+ - name of the association
+      #   +records+     - the association record(s) to be serialized
+      #   +opts+        - options for the association records
+      def add_includes(&block)
+        if include_associations = options.delete(:include)
+          base_only_or_except = { :except => options[:except],
+                                  :only => options[:only] }
+
+          include_has_options = include_associations.is_a?(Hash)
+          associations = include_has_options ? include_associations.keys : Array(include_associations)
+
+          for association in associations
+            records = case @record.class.reflect_on_association(association).macro
+            when :has_many, :has_and_belongs_to_many
+              @record.send(association).to_a
+            when :has_one, :belongs_to
+              @record.send(association)
+            end
+
+            unless records.nil?
+              association_options = include_has_options ? include_associations[association] : base_only_or_except
+              opts = options.merge(association_options)
+              yield(association, records, opts)
+            end
+          end
+
+          options[:include] = include_associations
+        end
+      end
+
       def serializable_record
         returning(serializable_record = {}) do
           serializable_names.each { |name| serializable_record[name] = @record.send(name) }
+          add_includes do |association, records, opts|
+            if records.is_a?(Enumerable)
+              serializable_record[association] = records.collect { |r| self.class.new(r, opts).serializable_record }
+            else
+              serializable_record[association] = self.class.new(records, opts).serializable_record
+            end
+          end
         end
       end
 
       def serialize
         # overwrite to implement
-      end        
-    
+      end
+
       def to_s(&block)
         serialize(&block)
       end