Integrated ActiveRecord::Dirty check support for delegated attributes

lib/delegate_belongs_to.rb

@@ -2,17 +2,13 @@
 # Creates methods on object which delegate to an association proxy.
 # see delegate_belongs_to for two uses
 # 
-# Todo - integrate with ActiveRecord::Dirty to make sure changes to delegate object are noticed
-# Should do
 # class User < ActiveRecord::Base; delegate_belongs_to :contact, :firstname; end
 # class Contact < ActiveRecord::Base; end
 # u = User.first
 # u.changed? # => false
 # u.firstname = 'Bobby'
 # u.changed? # => true
 # 
-# Right now the second call to changed? would return false
-# 
 # Todo - add has_one support. fairly straightforward addition
 ##
 module DelegateBelongsTo
@@ -41,39 +37,61 @@ def delegate_belongs_to(association, *attributes)
 
  def delegates_attributes_to(association, *attributes)
  raise ArgumentError, "Unknown association #{association}" unless reflection = reflect_on_association(association)
- 
+
  if attributes.empty? || attributes.delete(:defaults)
  column_names = reflection.klass.column_names
  default_rejected_delegate_columns.each {|column| column_names.delete(column) }
  attributes += column_names
  end
 
+ attributes.map!(&:to_s)
+
+ dirty_associations.merge!(association => attributes)
+
  attributes.each do |attribute|
  delegate attribute, :to => association, :allow_nil => true
  define_method("#{attribute}=") do |value|
  send("build_#{association}") unless send(association)
  send(association).send("#{attribute}=", value)
  end
 
- # if dirty = true
- # ActiveRecord::Dirty::DIRTY_SUFFIXES.each do |suffix|
- # define_method("#{attribute}#{suffix}") do
- # send("build_#{association}") unless send(association)
- # send(association).send("#{attribute}#{suffix}")
- # end
- # end
- # end
- # 
-
+ ActiveRecord::Dirty::DIRTY_SUFFIXES.each do |suffix|
+ define_method("#{attribute}#{suffix}") do
+ send("build_#{association}") unless send(association)
+ send(association).send("#{attribute}#{suffix}")
+ end
+ end
  end
  end
 
  end
+
+ module InstanceMethods
+
+ private
+
+ def changed_attributes_with_associations
+ result = {}
+ self.class.dirty_associations.each do |association, attributes|
+ association_changed_attributes = send(association).try(:changed_attributes) || {}
+ result.merge! association_changed_attributes.slice(*attributes)
+ end
+ changed_attributes_without_associations.merge!(result)
+ changed_attributes_without_associations
+ end
+ end
 
  def self.included(base)
  base.extend ClassMethods
+ base.send :include, InstanceMethods
+
  base.class_inheritable_accessor :default_rejected_delegate_columns
  base.default_rejected_delegate_columns = ['created_at','created_on','updated_at','updated_on','lock_version','type','id','position','parent_id','lft','rgt']
+
+ base.class_inheritable_accessor :dirty_associations
+ base.dirty_associations = {}
+
+ base.alias_method_chain :changed_attributes, :associations
  end
 end
 

spec/model/dirty_partial_spec.rb

@@ -0,0 +1,35 @@
+require File.join(File.dirname(__FILE__), '..', 'spec_helper')
+
+describe DelegateBelongsTo, 'with partial dirty delegations' do
+
+ before :all do
+ @fields = [:firstname]
+ UserNoDefault.belongs_to :contact
+ UserNoDefault.delegates_attributes_to :contact, :firstname
+ end
+
+ before :each do
+ @user = UserNoDefault.new
+ end 
+
+ [:lastname, :lastname_change, :lastname_changed?, :lastname_was, :lastname_will_change!].each do |method|
+ it "should not respond_to #{method}" do
+ @user.should_not respond_to(method)
+ end
+ end
+
+ describe "changing not tracked attribute" do
+ before :each do
+ @user.build_contact
+ @user.contact.lastname = "Smith"
+ end
+
+ it "should NOT be changed as user" do
+ @user.should_not be_changed
+ end
+
+ it "should be changed as user.contact" do
+ @user.contact.should be_changed
+ end
+ end
+end

spec/model/dirty_spec.rb

@@ -0,0 +1,156 @@
+require File.join(File.dirname(__FILE__), '..', 'spec_helper')
+
+describe DelegateBelongsTo, 'with dirty delegations' do
+
+ before :all do
+ @fields = Contact.column_names - ActiveRecord::Base.default_rejected_delegate_columns
+ UserDefault.belongs_to :contact
+ UserDefault.delegates_attributes_to :contact
+ end
+
+ before :each do
+ @user = UserDefault.new
+ end 
+
+ describe "reading from no contact" do
+ it "should return nil as firstname" do
+ @user.firstname.should be_nil
+ end
+
+ it "should return nil as change" do
+ @user.firstname_change.should be_nil
+ end
+
+ it "should not be changed" do
+ @user.firstname_changed?.should be_false
+ end
+
+ it "should return nil as firstname_was" do
+ @user.firstname_was.should be_nil
+ end
+
+ it "should return nil as lastname" do
+ @user.firstname_will_change!
+ @user.firstname_change.should == [nil, nil]
+ end
+ end
+
+
+ describe "reading from existing contact" do
+ before :each do
+ @user.build_contact
+ @user.contact.firstname = "John"
+ @user.contact.lastname = "Smith"
+ end
+
+ it "should be changed as user" do
+ @user.should be_changed
+ end
+
+ it "should be changed as contact" do
+ @user.contact.should be_changed
+ end
+
+ it "should read firstname" do
+ @user.firstname.should == "John"
+ end
+
+ it "should read lastname" do
+ @user.lastname.should == "Smith"
+ end
+
+ it "should return [nil, 'John'] as change" do
+ @user.firstname_change.should == [nil, "John"]
+ end
+
+ it "should not be changed" do
+ @user.firstname_changed?.should be_true
+ end
+
+ it "should return nil as firstname_was" do
+ @user.firstname_was.should be_nil
+ end
+
+ it "should return nil as lastname" do
+ @user.firstname_will_change!
+ @user.firstname_change.should == ['John', 'John']
+ end
+ end
+
+ describe "assigning value to delegators" do
+ it "should initialize association" do
+ @user.contact.should be_nil
+ @user.firstname = "John"
+ @user.contact.should_not be_nil
+ @user.firstname.should == "John"
+ end
+
+ it "should NOT initialize association second time" do
+ @user.firstname = "John"
+ contact_object_id = @user.contact.object_id
+ @user.lastname = "Smith"
+ @user.contact.object_id.should == contact_object_id
+ @user.firstname.should == "John"
+ end
+
+ end
+
+ [false, true].each do |bool|
+ describe "partial update #{bool}" do
+ before :all do
+ ActiveRecord::Base.partial_updates = bool
+ end
+
+ describe "#save" do
+ it "should clear changed_attribute in dirty assosiations" do
+ @user.firstname = "John"
+ @user.send(:changed_attributes).size.should == 1
+ @user.contact.send(:changed_attributes).size.should == 1
+ @user.save
+ @user.send(:changed_attributes).size.should == 0
+ @user.contact.send(:changed_attributes).size.should == 0
+ end
+ end
+
+ describe "#save(false)" do
+ it "should clear changed_attribute in dirty assosiations" do
+ @user.firstname = "John"
+ @user.send(:changed_attributes).size.should == 1
+ @user.contact.send(:changed_attributes).size.should == 1
+ @user.save(false)
+ @user.send(:changed_attributes).size.should == 0
+ @user.contact.send(:changed_attributes).size.should == 0
+ end
+ end
+
+ describe "#save!" do
+ it "should clear changed_attribute in dirty assosiations" do
+ @user.firstname = "John"
+ @user.send(:changed_attributes).size.should == 1
+ @user.contact.send(:changed_attributes).size.should == 1
+ @user.save!
+ @user.send(:changed_attributes).size.should == 0
+ @user.contact.send(:changed_attributes).size.should == 0
+ end
+ end
+
+ describe "#reload" do
+ before :each do
+ @user.firstname = "John"
+ @user.save!
+ end
+
+ it "should clear changed_attribute in dirty assosiations" do
+ @user.firstname = "Bob"
+ @user.send(:changed_attributes).size.should == 1
+ @user.contact.send(:changed_attributes).size.should == 1
+ @user.reload
+
+ @user.firstname.should == "John"
+ @user.send(:changed_attributes).size.should == 0
+ @user.contact.send(:changed_attributes).size.should == 0
+ end
+ end
+ end
+ end
+end