Adds suppport for ActiveModel::Dirty and ::AttributeMethods

* ActiveModel::Dirty
** Basic support for dirty tracking
** It does not bubble up any changes to casted models currently

* ActiveModel::AttributeMethods
** Attributes are now read and written through ActiveModel
** This also allows you to add your own attribute methods with
   prefix suffix and affix names. For more information check out
   ActiveModel::AttributeMethods::ClassMethods

.gitignore

@@ -5,3 +5,4 @@ pkg
 Gemfile*
 .rvmrc
 .bundle
+couchdb.std*

history.txt

@@ -1,6 +1,8 @@
 == Next Version
 
 * Major enhancements
+  * Dirty Tracking via ActiveModel
+  * ActiveModel Attribute Methods support
 
 * Minor enhancements
   * Fixing find("") issue (thanks epochwolf)

init.rb

@@ -1 +1 @@
-require File.join(File.dirname(__FILE__),'lib', 'couchrest', 'extended_document')
+require File.join(File.dirname(__FILE__),'lib', 'couchrest', 'model')

lib/couchrest/model/attributes.rb

@@ -1,13 +1,62 @@
 module CouchRest
   module Model
+    ReadOnlyPropertyError = Class.new(StandardError)
+
+    # Attributes Suffixes provide methods from ActiveModel
+    # to hook into. See methods such as #attribute= and
+    # #attribute? for their implementation
+    AttributeMethodSuffixes = ['', '=', '?']
+
     module Attributes
+      extend ActiveSupport::Concern
+
+      included do
+        include ActiveModel::AttributeMethods
+        attribute_method_suffix *AttributeMethodSuffixes
+      end
+
+      module ClassMethods
+        def attributes
+          properties.map {|prop| prop.name}
+        end
+      end
+
+      def initialize(*args)
+        self.class.attribute_method_suffix *AttributeMethodSuffixes
+        super
+      end
+
+      def attributes
+        self.class.attributes
+      end
+
+      ## Reads the attribute value.
+      # Assuming you have a property :title this would be called
+      # by `model_instance.title`
+      def attribute(name)
+        read_attribute(name)
+      end
+
+      ## Sets the attribute value.
+      # Assuming you have a property :title this would be called
+      # by `model_instance.title = 'hello'`
+      def attribute=(name, value)
+        raise ReadOnlyPropertyError, 'read only property' if find_property!(name).read_only
+        write_attribute(name, value)
+      end
+
+      ## Tests for both presence and truthiness of the attribute.
+      # Assuming you have a property :title # this would be called
+      # by `model_instance.title?`
+      def attribute?(name)
+        value = read_attribute(name)
+        !(value.nil? || value == false)
+      end
 
       ## Support for handling attributes
       #
       # This would be better in the properties file, but due to scoping issues
       # this is not yet possible.
-      #
-
       def prepare_all_attributes(doc = {}, options = {})
         apply_all_property_defaults
         if options[:directly_set_attributes]
@@ -29,11 +78,26 @@ module CouchRest
       end
       alias :attributes= :update_attributes_without_saving
 
+      def read_attribute(property)
+        prop = find_property!(property)
+        self[prop.to_s]
+      end
+
+      def write_attribute(property, value)
+        prop = find_property!(property)
+        self[prop.to_s] = prop.cast(self, value)
+      end
 
       private
 
+      def read_only_attributes
+        properties.select { |prop| prop.read_only }.map { |prop| prop.name }
+      end
+
       def directly_set_attributes(hash)
+        r_o_a = read_only_attributes
         hash.each do |attribute_name, attribute_value|
+          next if r_o_a.include? attribute_name
           if self.respond_to?("#{attribute_name}=")
             self.send("#{attribute_name}=", hash.delete(attribute_name))
           end
@@ -41,9 +105,10 @@ module CouchRest
       end
 
       def directly_set_read_only_attributes(hash)
-        property_list = self.properties.map{|p| p.name}
+        r_o_a = read_only_attributes
+        property_list = attributes
         hash.each do |attribute_name, attribute_value|
-          next if self.respond_to?("#{attribute_name}=")
+          next unless r_o_a.include? attribute_name
           if property_list.include?(attribute_name)
             write_attribute(attribute_name, hash.delete(attribute_name))
           end
@@ -56,12 +121,11 @@ module CouchRest
       end
 
       def check_properties_exist(attrs)
-        property_list = self.properties.map{|p| p.name}
+        property_list = attributes
         attrs.each do |attribute_name, attribute_value|
           raise NoMethodError, "Property #{attribute_name} not created" unless respond_to?("#{attribute_name}=") or property_list.include?(attribute_name)
         end
       end
-
     end
   end
 end

lib/couchrest/model/base.rb

@@ -16,6 +16,7 @@ module CouchRest
       include CouchRest::Model::Attributes
       include CouchRest::Model::Associations
       include CouchRest::Model::Validations
+      include CouchRest::Model::Dirty
 
       def self.subclasses
         @subclasses ||= []

lib/couchrest/model/dirty.rb

@@ -0,0 +1,44 @@
+# encoding: utf-8
+require 'active_model/dirty'
+
+module CouchRest #:nodoc:
+  module Model #:nodoc:
+
+    # Dirty Tracking support via ActiveModel
+    # mixin methods include:
+    #   #changed?, #changed, #changes, #previous_changes
+    #   #<attribute>_changed?, #<attribute>_change,
+    #   #reset_<attribute>!, #<attribute>_will_change!,
+    #   and #<attribute>_was
+    #
+    # Please see the specs or the documentation of
+    # ActiveModel::Dirty for more information
+    module Dirty
+      extend ActiveSupport::Concern
+
+      included do
+        include ActiveModel::Dirty
+        after_save :clear_changed_attributes
+      end
+
+      def initialize(*args)
+        super
+        @changed_attributes.clear if @changed_attributes
+      end
+
+      def write_attribute(name, value)
+        meth = :"#{name}_will_change!"
+        __send__ meth if respond_to? meth
+        super
+      end
+
+      private
+
+      def clear_changed_attributes
+        @previously_changed = changes
+        @changed_attributes.clear
+        true
+      end
+    end
+  end
+end

lib/couchrest/model/properties.rb

@@ -1,4 +1,5 @@
 # encoding: utf-8
+require 'set'
 module CouchRest
   module Model
     module Properties
@@ -22,16 +23,6 @@ module CouchRest
         self.class.properties
       end
 
-      def read_attribute(property)
-        prop = find_property!(property)
-        self[prop.to_s]
-      end
-
-      def write_attribute(property, value)
-        prop = find_property!(property)
-        self[prop.to_s] = prop.cast(self, value)
-      end
-
       def apply_all_property_defaults
         return if self.respond_to?(:new?) && (new? == false)
         # TODO: cache the default object
@@ -94,8 +85,7 @@ module CouchRest
               type = [type] # inject as an array
             end
             property = Property.new(name, type, options)
-            create_property_getter(property)
-            create_property_setter(property) unless property.read_only == true
+            create_property_alias(property) if property.alias
             if property.type_class.respond_to?(:validates_casted_model)
               validates_casted_model property.name
             end
@@ -103,49 +93,15 @@ module CouchRest
             property
           end
 
-          # defines the getter for the property (and optional aliases)
-          def create_property_getter(property)
-            # meth = property.name
+          def create_property_alias(property)
             class_eval <<-EOS, __FILE__, __LINE__ + 1
-              def #{property.name}
-                read_attribute('#{property.name}')
+              def #{property.alias.to_s}
+                #{property.name}
               end
             EOS
-
-            if ['boolean', TrueClass.to_s.downcase].include?(property.type.to_s.downcase)
-              class_eval <<-EOS, __FILE__, __LINE__
-                def #{property.name}?
-                  value = read_attribute('#{property.name}')
-                  !(value.nil? || value == false)
-                end
-              EOS
-            end
-
-            if property.alias
-              class_eval <<-EOS, __FILE__, __LINE__ + 1
-                alias #{property.alias.to_sym} #{property.name.to_sym}
-              EOS
-            end
-          end
-
-          # defines the setter for the property (and optional aliases)
-          def create_property_setter(property)
-            property_name = property.name
-            class_eval <<-EOS
-              def #{property_name}=(value)
-                write_attribute('#{property_name}', value)
-              end
-            EOS
-
-            if property.alias
-              class_eval <<-EOS
-                alias #{property.alias.to_sym}= #{property_name.to_sym}=
-              EOS
-            end
           end
 
       end # module ClassMethods
-
     end
   end
 end

lib/couchrest_model.rb

@@ -48,6 +48,7 @@ require "couchrest/model/collection"
 require "couchrest/model/attribute_protection"
 require "couchrest/model/attributes"
 require "couchrest/model/associations"
+require "couchrest/model/dirty"
 
 # Monkey patches applied to couchrest
 require "couchrest/model/support/couchrest"

spec/couchrest/dirty_spec.rb

@@ -0,0 +1,126 @@
+require File.expand_path("../../spec_helper", __FILE__)
+
+class DirtyModel < CouchRest::Model::Base
+  use_database TEST_SERVER.default_database
+  property :name
+  property :color
+  validates_presence_of :name
+end
+
+describe 'Dirty Tracking', '#changed?' do
+  before(:each) do
+    @dm = DirtyModel.new
+    @dm.name = 'will'
+  end
+
+  it 'brand new models should not be changed by default' do
+    DirtyModel.new.should_not be_changed
+  end
+
+  it 'save should reset changed?' do
+    @dm.should be_changed
+    @dm.save
+    @dm.should_not be_changed
+  end
+
+  it 'save! should reset changed?' do
+    @dm.should be_changed
+    @dm.save!
+    @dm.should_not be_changed
+  end
+
+  it 'a failed save should preserve changed?' do
+    @dm.name = ''
+    @dm.should be_changed
+    @dm.save.should be_false
+    @dm.should be_changed
+  end
+
+  it 'should be true if there have been changes' do
+    @dm.name = 'not will'
+    @dm.should be_changed
+  end
+end
+
+describe 'Dirty Tracking', '#changed' do
+  it 'should be an array of the changed attributes' do
+    dm = DirtyModel.new
+    dm.changed.should == []
+    dm.name = 'will'
+    dm.changed.should == ['name']
+    dm.color = 'red'
+    dm.changed.should =~ ['name', 'color']
+  end
+end
+
+describe 'Dirty Tracking', '#changes' do
+  it 'should be a Map of changed attrs => [original value, new value]' do
+    dm = DirtyModel.new(:name => 'will', :color => 'red')
+    dm.save!
+    dm.should_not be_changed
+
+    dm.name = 'william'
+    dm.color = 'blue'
+
+    dm.changes.should == { 'name' => ['will', 'william'], 'color' => ['red', 'blue'] }
+  end
+end
+
+describe 'Dirty Tracking', '#previous_changes' do
+  it 'should store the previous changes after a save' do
+    dm = DirtyModel.new(:name => 'will', :color => 'red')
+    dm.save!
+    dm.should_not be_changed
+
+    dm.name = 'william'
+    dm.save!
+
+    dm.previous_changes.should == { 'name' => ['will', 'william'] }
+  end
+end
+
+describe 'Dirty Tracking', 'attribute methods' do
+  before(:each) do
+     @dm = DirtyModel.new(:name => 'will', :color => 'red')
+     @dm.save!
+  end
+
+  describe '#<attr>_changed?' do
+    it 'it should know if a specific property was changed' do
+      @dm.name = 'william'
+      @dm.should     be_name_changed
+      @dm.should_not be_color_changed
+    end
+  end
+
+  describe 'Dirty Tracking', '#<attr>_change' do
+    it 'should be an array of [original value, current value]' do
+      @dm.name = 'william'
+      @dm.name_change.should == ['will', 'william']
+    end
+  end
+
+  describe 'Dirty Tracking', '#<attr>_was' do
+    it 'should return what the attribute was' do
+      @dm.name = 'william'
+      @dm.name_was.should == 'will'
+    end
+  end
+
+  describe 'Dirty Tracking', '#reset_<attr>!' do
+    it 'should reset the attribute to what it was' do
+      @dm.name = 'william'
+
+      @dm.reset_name!
+      @dm.name.should == 'will'
+    end
+  end
+
+  describe 'Dirty Tracking', '#<attr>_will_change!' do
+    it 'should manually mark the attribute as changed' do
+      @dm.should_not be_name_changed
+      @dm.name_will_change!
+      @dm.should be_name_changed
+    end
+  end
+end

spec/couchrest/property_spec.rb

@@ -9,6 +9,20 @@ require File.join(FIXTURE_PATH, 'more', 'event')
 require File.join(FIXTURE_PATH, 'more', 'user')
 require File.join(FIXTURE_PATH, 'more', 'course')
 
+describe 'Attributes' do
+  class AttrDoc < CouchRest::Model::Base
+    property :one
+    property :two
+  end
+
+  it '.attributes should have an array of attribute names' do
+   AttrDoc.attributes.should =~ ['two', 'one']
+  end
+
+  it '#attributes should have an array of attribute names' do
+   AttrDoc.new.attributes.should =~ ['two', 'one']
+  end
+end
 
 describe "Model properties" do