add discard_if option to has_many_with_association_options

git-svn-id: http://svn.jamesgolick.com/attribute_fu/trunk@64 80b79608-713f-0410-8737-d8c0d0c1b50c

lib/attribute_fu/associations.rb

@@ -7,7 +7,7 @@ def self.included(base) #:nodoc:
         class << self; alias_method_chain :has_many, :association_option; end
 
         class_inheritable_accessor  :managed_association_attributes
-        write_inheritable_attribute :managed_association_attributes, []
+        write_inheritable_attribute :managed_association_attributes, {}
 
         after_update :save_managed_associations
       end
@@ -16,7 +16,7 @@ class << self; alias_method_chain :has_many, :association_option; end
     def method_missing(method_name, *args) #:nodoc:
       if method_name.to_s =~ /.+?\_attributes=/
         association_name = method_name.to_s.gsub '_attributes=', ''
-        association      = managed_association_attributes.detect { |element| element == association_name.to_sym } || managed_association_attributes.detect { |element| element == association_name.pluralize.to_sym }
+        association      = managed_association_attributes.keys.detect { |element| element == association_name.to_sym } || managed_association_attributes.keys.detect { |element| element == association_name.pluralize.to_sym }
 
         unless association.nil?
           has_many_attributes association, args.first
@@ -51,10 +51,16 @@ def has_many_attributes(association_id, attributes) #:nodoc:
           object = association.detect { |associated| associated.id.to_s == id }
           object.attributes = object_attrs unless object.nil?
         end
+
+        # discard blank attributes if discard_if proc exists
+        unless (discard = managed_association_attributes[association_id][:discard_if]).nil?
+          association.reject! { |object| object.new_record? && discard.call(object) }
+          association.delete(*association.select { |object| discard.call(object) })
+        end
       end
 
       def save_managed_associations #:nodoc:
-        managed_association_attributes.each do |association_id|
+        managed_association_attributes.keys.each do |association_id|
           association = send(association_id)
           association.each(&:save)
 
@@ -89,7 +95,8 @@ module ClassMethods
       #
       def has_many_with_association_option(association_id, options = {}, &extension)
         unless (config = options.delete(:attributes)).nil?
-          self.managed_association_attributes << association_id
+          managed_association_attributes[association_id] = {}
+          managed_association_attributes[association_id][:discard_if] = options.delete(:discard_if) if options.has_key?(:discard_if)
         end
 
         has_many_without_association_option(association_id, options, &extension)

test/test/unit/photo_test.rb

@@ -6,9 +6,7 @@ class PhotoTest < ActiveSupport::TestCase
   context "comment_attributes" do
     context "with valid children" do
       setup do
-        @photo = Photo.create
-        @gob = @photo.comments.create :author => "Gob Bluth",  :body => "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed..."
-        @bob = @photo.comments.create :author => "Bob Loblaw", :body => "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed..."
+        create_photo_and_children
 
         @photo.comment_attributes = { @gob.id.to_s => { :author => "Buster Bluth", :body => "I said it was _our_ nausia..." },
                                       :new         => { "0" => { :author => "George-Michael", :body => "I was going to smoke the marijuana like a ciggarette." },
@@ -70,6 +68,36 @@ class PhotoTest < ActiveSupport::TestCase
           assert @photo.comments.empty?, "one or more comments not removed: #{@photo.comments.inspect}"
         end
       end
+
+      context "with discard_if => proc { }" do
+        setup do
+          Photo.class_eval do
+            has_many :comments, :attributes => true, :discard_if => proc { |comment| comment.author.blank? && comment.body.blank? }
+          end
+
+          create_photo_and_children
+
+
+          @photo.comment_attributes = { @gob.id.to_s => { :author => "Buster Bluth", :body => "I said it was _our_ nausia..." },
+                                        @bob.id.to_s => { :author => '', :body => '' },
+                                        :new         => { "0" => { :author => "", :body => "" }}}
+          @photo.save
+        end
+
+        teardown do
+          Photo.class_eval do
+            managed_association_attributes[:comments].delete(:discard_if)
+          end
+        end
+
+        should "discard any child objects for which discard_if evaluates to true" do
+          assert !@photo.comments.any? { |comment| comment.author.blank? && comment.body.blank? }, @photo.comments.inspect
+        end
+
+        should "not discard other objects" do
+          assert_equal 1, @photo.comments.length
+        end
+      end
     end
 
     context "updating with invalid children" do
@@ -87,4 +115,11 @@ class PhotoTest < ActiveSupport::TestCase
       end
     end
   end
+
+  private
+    def create_photo_and_children
+      @photo = Photo.create
+      @gob = @photo.comments.create :author => "Gob Bluth",  :body => "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed..."
+      @bob = @photo.comments.create :author => "Bob Loblaw", :body => "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed..."
+    end
 end