Added ActiveRecord::Base#to_json/from_json (currently does not support :include like to_xml) [DHH]. Added ActiveRecord::Base#from_xml [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7519 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,12 @@
 *SVN*
 
+* Added ActiveRecord::Base#to_json/from_json (currently does not support :include like to_xml) [DHH]
+
+* Added ActiveRecord::Base#from_xml [DHH]. Example:
+
+    xml = "<person><name>David</name></person>"
+    Person.new.from_xml(xml).name # => "David"
+
 * Define dynamic finders as real methods after first usage. [bscofield]
 
 * Deprecation: remove deprecated threaded_connections methods. Use allow_concurrency instead.  [Jeremy Kemper]

activerecord/lib/active_record.rb

@@ -49,7 +49,7 @@ require 'active_record/locking/pessimistic'
 require 'active_record/migration'
 require 'active_record/schema'
 require 'active_record/calculations'
-require 'active_record/xml_serialization'
+require 'active_record/serialization'
 require 'active_record/attribute_methods'
 
 ActiveRecord::Base.class_eval do
@@ -65,7 +65,7 @@ ActiveRecord::Base.class_eval do
   include ActiveRecord::Transactions
   include ActiveRecord::Reflection
   include ActiveRecord::Calculations
-  include ActiveRecord::XmlSerialization
+  include ActiveRecord::Serialization
   include ActiveRecord::AttributeMethods
 end
 

activerecord/lib/active_record/associations/association_collection.rb

@@ -158,6 +158,7 @@ module ActiveRecord
         end
       end
 
+
       protected
         def method_missing(method, *args, &block)
           if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
@@ -218,4 +219,4 @@ module ActiveRecord
                
     end
   end
-end
+end

activerecord/lib/active_record/serialization.rb

@@ -0,0 +1,59 @@
+module ActiveRecord #:nodoc:
+  module Serialization
+    class Serializer #:nodoc:
+      attr_reader :options
+    
+      def initialize(record, options = {})
+        @record, @options = record, options.dup
+      end
+
+      # To replicate the behavior in ActiveRecord#attributes,
+      # :except takes precedence over :only.  If :only is not set
+      # for a N level model but is set for the N+1 level models,
+      # then because :except is set to a default value, the second
+      # level model can have both :except and :only set.  So if
+      # :only is set, always delete :except.
+      def serializable_attribute_names
+        attribute_names = @record.attribute_names
+
+        if options[:only]
+          options.delete(:except)
+          attribute_names = attribute_names & Array(options[:only]).collect { |n| n.to_s }
+        else
+          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
+        end
+      end
+      
+      def serializable_names
+        serializable_attribute_names + serializable_method_names
+      end
+
+      def serializable_record
+        returning(serializable_record = {}) do
+          serializable_names.each { |name| serializable_record[name] = @record.send(name) }
+        end
+      end
+
+      def serialize
+        # overwrite to implement
+      end        
+    
+      def to_s(&block)
+        serialize(&block)
+      end
+    end
+  end
+end
+
+require 'active_record/serializers/xml_serializer'
+require 'active_record/serializers/json_serializer'

activerecord/lib/active_record/serializers/json_serializer.rb

@@ -0,0 +1,18 @@
+module ActiveRecord #:nodoc:
+  module Serialization
+    def to_json(options = {}, &block)
+      JsonSerializer.new(self, options).to_s
+    end
+
+    def from_json(json)
+      self.attributes = ActiveSupport::JSON.decode(json)
+      self
+    end
+
+    class JsonSerializer < ActiveRecord::Serialization::Serializer #:nodoc:
+      def serialize
+        serializable_record.to_json
+      end
+    end
+  end
+end

activerecord/lib/active_record/serializers/xml_serializer.rb

@@ -1,5 +1,5 @@
 module ActiveRecord #:nodoc:
-  module XmlSerialization
+  module Serialization
     # Builds an XML document to represent the model.   Some configuration is
     # availble through +options+, however more complicated cases should use 
     # override ActiveRecord's to_xml.
@@ -124,15 +124,14 @@ module ActiveRecord #:nodoc:
       serializer = XmlSerializer.new(self, options)
       block_given? ? serializer.to_s(&block) : serializer.to_s
     end
+
+    def from_xml(xml)
+      self.attributes = Hash.from_xml(xml).values.first
+      self
+    end
   end
 
-  class XmlSerializer #:nodoc:
-    attr_reader :options
-    
-    def initialize(record, options = {})
-      @record, @options = record, options.dup
-    end
-    
+  class XmlSerializer < ActiveRecord::Serialization::Serializer #:nodoc:
     def builder
       @builder ||= begin
         options[:indent] ||= 2
@@ -164,17 +163,7 @@ module ActiveRecord #:nodoc:
     # level model can have both :except and :only set.  So if
     # :only is set, always delete :except.
     def serializable_attributes
-      attribute_names = @record.attribute_names
-
-      if options[:only]
-        options.delete(:except)
-        attribute_names = attribute_names & Array(options[:only]).collect { |n| n.to_s }
-      else
-        options[:except] = Array(options[:except]) | Array(@record.class.inheritance_column)
-        attribute_names = attribute_names - options[:except].collect { |n| n.to_s }
-      end
-      
-      attribute_names.collect { |name| Attribute.new(name, @record) }
+      serializable_attribute_names.collect { |name| Attribute.new(name, @record) }
     end
 
     def serializable_method_attributes
@@ -265,8 +254,6 @@ module ActiveRecord #:nodoc:
         yield builder if block_given?
       end
     end        
-    
-    alias_method :to_s, :serialize
 
     class Attribute #:nodoc:
       attr_reader :name, :value, :type

activerecord/test/fixtures/contact.rb

@@ -0,0 +1,16 @@
+class Contact < ActiveRecord::Base
+  # mock out self.columns so no pesky db is needed for these tests
+  def self.column(name, sql_type = nil, options = {})
+    @columns ||= []
+    @columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, options[:default], sql_type.to_s, options[:null])
+  end
+
+  column :name,        :string
+  column :age,         :integer
+  column :avatar,      :binary
+  column :created_at,  :datetime
+  column :awesome,     :boolean
+  column :preferences, :string
+  
+  serialize :preferences
+end

activerecord/test/serialization_test.rb

@@ -0,0 +1,47 @@
+require 'abstract_unit'
+require 'fixtures/contact'
+
+class SerializationTest < Test::Unit::TestCase
+  FORMATS = [ :xml, :json ]
+  
+  def setup
+    @contact_attributes = {
+      :name        => 'aaron stack',
+      :age         => 25,
+      :avatar      => 'binarydata',
+      :created_at  => Time.utc(2006, 8, 1),
+      :awesome     => false,
+      :preferences => { :gem => 'ruby' }
+    }
+
+    @contact = Contact.new(@contact_attributes)
+  end
+  
+  def test_serialize_should_be_reversible
+    for format in FORMATS
+      @serialized = Contact.new.send("to_#{format}")
+      contact = Contact.new.send("from_#{format}", @serialized)
+      
+      assert_equal @contact_attributes.keys.collect(&:to_s).sort, contact.attributes.keys.collect(&:to_s).sort, "For #{format}"
+    end
+  end
+
+  def test_serialize_should_allow_attribute_only_filtering
+    for format in FORMATS
+      @serialized = Contact.new(@contact_attributes).send("to_#{format}", :only => [ :age, :name ])
+      contact = Contact.new.send("from_#{format}", @serialized)
+      assert_equal @contact_attributes[:name], contact.name, "For #{format}"
+      assert_nil contact.avatar, "For #{format}"
+    end
+  end
+
+  def test_serialize_should_allow_attribute_except_filtering
+    for format in FORMATS
+      @serialized = Contact.new(@contact_attributes).send("to_#{format}", :except => [ :age, :name ])
+      contact = Contact.new.send("from_#{format}", @serialized)
+      assert_nil contact.name, "For #{format}"
+      assert_nil contact.age, "For #{format}"
+      assert_equal @contact_attributes[:awesome], contact.awesome, "For #{format}"
+    end
+  end
+end

activerecord/test/xml_serialization_test.rb

@@ -1,26 +1,10 @@
 require 'abstract_unit'
+require 'fixtures/contact'
 require 'fixtures/post'
 require 'fixtures/author'
 require 'fixtures/tagging'
 require 'fixtures/comment'
 
-class Contact < ActiveRecord::Base
-  # mock out self.columns so no pesky db is needed for these tests
-  def self.columns() @columns ||= []; end
-  def self.column(name, sql_type = nil, default = nil, null = true)
-    columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, default, sql_type.to_s, null)
-  end
-
-  column :name,        :string
-  column :age,         :integer
-  column :avatar,      :binary
-  column :created_at,  :datetime
-  column :awesome,     :boolean
-  column :preferences, :string
-  
-  serialize :preferences
-end
-
 class XmlSerializationTest < Test::Unit::TestCase
   def test_should_serialize_default_root
     @xml = Contact.new.to_xml
@@ -47,18 +31,6 @@ class XmlSerializationTest < Test::Unit::TestCase
     assert_match %r{<created_at},     @xml
   end
 
-  def test_should_allow_attribute_filtering
-    @xml = Contact.new.to_xml :only => [:age, :name]
-    assert_match %r{<name},          @xml
-    assert_match %r{<age},           @xml
-    assert_no_match %r{<created-at}, @xml
-    
-    @xml = Contact.new.to_xml :except => [:age, :name]
-    assert_no_match %r{<name},    @xml
-    assert_no_match %r{<age},     @xml
-    assert_match %r{<created-at}, @xml
-  end
-  
   def test_should_include_yielded_additions
     @xml = Contact.new.to_xml do |xml|
       xml.creator "David"