From 4dbf694e5112952ed6e4abd6016e3b50da620694 Mon Sep 17 00:00:00 2001
From: Andrew Williams <sobakasu@gmail.com>
Date: Tue, 1 Mar 2011 01:30:41 +1030
Subject: [PATCH] now using ActiveModel::Dirty. only writes to database if
 model.changed?

---
 .gitignore                                  |   2 +-
 lib/couchrest/model/base.rb                 |   3 +-
 lib/couchrest/model/casted_array.rb         |  22 ++-
 lib/couchrest/model/casted_hash.rb          |  20 +++
 lib/couchrest/model/casted_model.rb         |   3 +
 lib/couchrest/model/dirty.rb                |  41 +++++
 lib/couchrest/model/extended_attachments.rb |   9 ++
 lib/couchrest/model/persistence.rb          |  19 ++-
 lib/couchrest/model/properties.rb           |  61 +++++--
 lib/couchrest/model/property.rb             |   4 +
 lib/couchrest_model.rb                      |   6 +-
 spec/couchrest/base_spec.rb                 |   1 +
 spec/couchrest/dirty_spec.rb                | 167 ++++++++++++++++++++
 spec/fixtures/base.rb                       |   2 +-
 14 files changed, 342 insertions(+), 18 deletions(-)
 create mode 100644 lib/couchrest/model/casted_hash.rb
 create mode 100644 lib/couchrest/model/dirty.rb
 create mode 100644 spec/couchrest/dirty_spec.rb

diff --git a/.gitignore b/.gitignore
index 5b1ad4c..f6c7e5a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,4 +6,4 @@ pkg
 .bundle
 couchdb.std*
 *.*~
-
+spec.out
diff --git a/lib/couchrest/model/base.rb b/lib/couchrest/model/base.rb
index b52ad59..9d47d1b 100644
--- a/lib/couchrest/model/base.rb
+++ b/lib/couchrest/model/base.rb
@@ -16,6 +16,7 @@ module CouchRest
       include CouchRest::Model::PropertyProtection
       include CouchRest::Model::Associations
       include CouchRest::Model::Validations
+      include CouchRest::Model::Dirty
 
       def self.subclasses
         @subclasses ||= []
@@ -55,7 +56,7 @@ module CouchRest
         after_initialize if respond_to?(:after_initialize)
       end
      
-      
+       
       # Temp solution to make the view_by methods available
       def self.method_missing(m, *args, &block)
         if has_view?(m)
diff --git a/lib/couchrest/model/casted_array.rb b/lib/couchrest/model/casted_array.rb
index a52f152..6d187b5 100644
--- a/lib/couchrest/model/casted_array.rb
+++ b/lib/couchrest/model/casted_array.rb
@@ -5,6 +5,7 @@
 
 module CouchRest::Model
   class CastedArray < Array
+    include CouchRest::Model::Dirty
     attr_accessor :casted_by
     attr_accessor :property
 
@@ -14,15 +15,34 @@ module CouchRest::Model
     end
     
     def << obj
+      couchrest_parent_will_change!
       super(instantiate_and_cast(obj))
     end
     
     def push(obj)
+      couchrest_parent_will_change!
       super(instantiate_and_cast(obj))
     end
+
+    def pop
+      couchrest_parent_will_change!
+      super
+    end
+
+    def shift
+      couchrest_parent_will_change!
+      super
+    end
+
+    def unshift(obj)
+      couchrest_parent_will_change!
+      super(obj)
+    end
     
     def []= index, obj
-      super(index, instantiate_and_cast(obj))
+      value = instantiate_and_cast(obj)
+      couchrest_parent_will_change! if value != self[index]
+      super(index, value)
     end
 
     protected
diff --git a/lib/couchrest/model/casted_hash.rb b/lib/couchrest/model/casted_hash.rb
new file mode 100644
index 0000000..737c91b
--- /dev/null
+++ b/lib/couchrest/model/casted_hash.rb
@@ -0,0 +1,20 @@
+#
+# Wrapper around Hash so that the casted_by attribute is set.
+
+module CouchRest::Model
+  class CastedHash < Hash
+    include CouchRest::Model::Dirty
+    attr_accessor :casted_by
+
+    def []= index, obj
+      couchrest_parent_will_change! if obj != self[index]
+      super(index, obj)
+    end
+
+    # needed for dirty
+    def attributes
+      self
+    end
+
+  end
+end
diff --git a/lib/couchrest/model/casted_model.rb b/lib/couchrest/model/casted_model.rb
index 4d931fc..19b6fc9 100644
--- a/lib/couchrest/model/casted_model.rb
+++ b/lib/couchrest/model/casted_model.rb
@@ -10,6 +10,7 @@ module CouchRest::Model
       include CouchRest::Model::PropertyProtection
       include CouchRest::Model::Associations
       include CouchRest::Model::Validations
+      include CouchRest::Model::Dirty
       attr_accessor :casted_by
     end
     
@@ -20,6 +21,7 @@ module CouchRest::Model
     end
     
     def []= key, value
+      couchrest_attribute_will_change!(key) unless self[key] == value
       super(key.to_s, value)
     end
     
@@ -64,5 +66,6 @@ module CouchRest::Model
       end
     end
     alias :attributes= :update_attributes_without_saving
+
   end
 end
diff --git a/lib/couchrest/model/dirty.rb b/lib/couchrest/model/dirty.rb
new file mode 100644
index 0000000..31199b8
--- /dev/null
+++ b/lib/couchrest/model/dirty.rb
@@ -0,0 +1,41 @@
+# encoding: utf-8
+
+I18n.load_path << File.join(
+  File.dirname(__FILE__), "validations", "locale", "en.yml"
+)
+
+module CouchRest
+  module Model
+
+    # This applies to both Model::Base and Model::CastedModel
+    module Dirty
+      extend ActiveSupport::Concern
+
+      included do
+        include ActiveModel::Dirty
+      end
+
+      def couchrest_attribute_will_change!(attr)
+        return if attr.nil?
+        self.send("#{attr}_will_change!")
+        if pkey = casted_by_attribute
+          @casted_by.couchrest_attribute_will_change!(pkey)
+        end
+      end
+      
+      def couchrest_parent_will_change!
+        @casted_by.couchrest_attribute_will_change!(casted_by_attribute) if @casted_by
+      end
+
+      private
+      
+      # return the attribute name this object is referenced by in the parent
+      def casted_by_attribute
+        return nil unless @casted_by
+        attr = @casted_by.attributes
+        attr.keys.detect { |k| attr[k] == self }
+      end
+
+    end
+  end
+end
diff --git a/lib/couchrest/model/extended_attachments.rb b/lib/couchrest/model/extended_attachments.rb
index 42bccec..c2a5ffc 100644
--- a/lib/couchrest/model/extended_attachments.rb
+++ b/lib/couchrest/model/extended_attachments.rb
@@ -1,6 +1,12 @@
 module CouchRest
   module Model
     module ExtendedAttachments
+      extend ActiveSupport::Concern
+      include ActiveModel::Dirty
+      included do
+        # for _attachments_will_change!
+        define_attribute_methods [:_attachments]
+      end
 
       # Add a file attachment to the current document. Expects
       # :file and :name to be included in the arguments.
@@ -35,6 +41,7 @@ module CouchRest
       # deletes a file attachment from the current doc
       def delete_attachment(attachment_name)
         return unless attachments
+        _attachments_will_change! if attachments.include?(attachment_name)
         attachments.delete attachment_name
       end
 
@@ -66,6 +73,8 @@ module CouchRest
         def set_attachment_attr(args)
           content_type = args[:content_type] ? args[:content_type] : get_mime_type(args[:file].path)
           content_type ||= (get_mime_type(args[:name]) || 'text/plain')
+
+          _attachments_will_change!
           attachments[args[:name]] = {
             'content_type' => content_type,
             'data'         => args[:file].read
diff --git a/lib/couchrest/model/persistence.rb b/lib/couchrest/model/persistence.rb
index 9f67175..f4c7970 100644
--- a/lib/couchrest/model/persistence.rb
+++ b/lib/couchrest/model/persistence.rb
@@ -12,7 +12,9 @@ module CouchRest
           _run_save_callbacks do
             set_unique_id if new? && self.respond_to?(:set_unique_id)
             result = database.save_doc(self)
-            (result["ok"] == true) ? self : false
+            ret = (result["ok"] == true) ? self : false
+            @changed_attributes.clear if ret && @changed_attributes
+            ret
           end
         end
       end
@@ -28,10 +30,13 @@ module CouchRest
       def update(options = {})
         raise "Calling #{self.class.name}#update on document that has not been created!" if self.new?
         return false unless perform_validations(options)
+        return true unless self.changed?
         _run_update_callbacks do
           _run_save_callbacks do
             result = database.save_doc(self)
-            result["ok"] == true
+            ret = result["ok"] == true
+            @changed_attributes.clear if ret && @changed_attributes
+            ret
           end
         end
       end
@@ -140,12 +145,18 @@ module CouchRest
         # should use the class name as part of the unique id.
         def unique_id method = nil, &block
           if method
+            define_method :get_unique_id do
+              self.send(method)
+            end
             define_method :set_unique_id do
-              self['_id'] ||= self.send(method)
+              self['_id'] ||= get_unique_id
             end
           elsif block
+            define_method :get_unique_id do
+              block.call(self)
+            end
             define_method :set_unique_id do
-              uniqid = block.call(self)
+              uniqid = get_unique_id
               raise ArgumentError, "unique_id block must not return nil" if uniqid.nil?
               self['_id'] ||= uniqid
             end
diff --git a/lib/couchrest/model/properties.rb b/lib/couchrest/model/properties.rb
index 481d135..8f54fee 100644
--- a/lib/couchrest/model/properties.rb
+++ b/lib/couchrest/model/properties.rb
@@ -3,6 +3,7 @@ module CouchRest
   module Model
     module Properties
       extend ActiveSupport::Concern
+      include ActiveModel::Dirty
 
       included do
         extlib_inheritable_accessor(:properties) unless self.respond_to?(:properties)
@@ -38,11 +39,33 @@ module CouchRest
 
       # Store a casted value in the current instance of an attribute defined
       # with a property.
+      # TODO: mixin dirty functionality into value (?)
       def write_attribute(property, value)
         prop = find_property!(property)
         self[prop.to_s] = prop.is_a?(String) ? value : prop.cast(self, value)
       end
 
+      # write property, update dirty status
+      def write_attribute_dirty(property, value)
+        prop = find_property!(property)
+        value = prop.is_a?(String) ? value : prop.cast(self, value)
+        self.send("#{prop}_will_change!") unless self[prop.to_s] == value
+        write_attribute(property, value)
+      end
+
+      def []=(key,value)
+        old_id = get_unique_id if self.respond_to?(:get_unique_id)
+
+        super(key, value)
+
+        if self.respond_to?(:get_unique_id)
+          # if we have set an attribute that results in the _id changing (unique_id),
+          # force changed? to return true so that the record can be saved
+          new_id = get_unique_id
+          changed_attributes["_id"] = new_id if old_id != new_id
+        end
+      end
+
       # Takes a hash as argument, and applies the values by using writer methods
       # for each key. It doesn't save the document at the end. Raises a NoMethodError if the corresponding methods are
       # missing. In case of error, no attributes are changed.
@@ -50,12 +73,23 @@ module CouchRest
         # Remove any protected and update all the rest. Any attributes
         # which do not have a property will simply be ignored.
         attrs = remove_protected_attributes(hash)
-        directly_set_attributes(attrs)
+        directly_set_attributes(attrs, :dirty => true)
       end
       alias :attributes= :update_attributes_without_saving
 
+      # needed for Dirty
+      def attributes
+        ret = {}
+        self.class.properties.each do |property|
+          ret[property.name] = read_attribute(property)
+        end
+        ret
+      end
+
+      def find_property(property)
+        property.is_a?(Property) ? property : self.class.properties.detect {|p| p.to_s == property.to_s}
+      end
 
-      private
       # The following methods should be accessable by the Model::Base Class, but not by anything else!
       def apply_all_property_defaults
         return if self.respond_to?(:new?) && (new? == false)
@@ -76,17 +110,26 @@ module CouchRest
       end
 
       def find_property!(property)
-        prop = property.is_a?(Property) ? property : self.class.properties.detect {|p| p.to_s == property.to_s}
+        prop = find_property(property)
         raise ArgumentError, "Missing property definition for #{property.to_s}" if prop.nil?
         prop
       end
 
       # Set all the attributes and return a hash with the attributes
       # that have not been accepted.
-      def directly_set_attributes(hash)
+      def directly_set_attributes(hash, options = {})
         hash.reject do |attribute_name, attribute_value|
           if self.respond_to?("#{attribute_name}=")
-            self.send("#{attribute_name}=", attribute_value)
+            if find_property(attribute_name)
+              if options[:dirty]
+                self.write_attribute_dirty(attribute_name, attribute_value)
+              else
+                # set attribute without updating dirty status
+                self.write_attribute(attribute_name, attribute_value)
+              end
+            else
+              self.send("#{attribute_name}=", attribute_value)
+            end
             true
           elsif mass_assign_any_attribute # config option
             self[attribute_name] = attribute_value
@@ -126,7 +169,7 @@ module CouchRest
           end
           existing_property = self.properties.find{|p| p.name == name.to_s}
           if existing_property.nil? || (existing_property.default != opts[:default])
-            define_property(name, opts, &block)
+            define_property(name, opts, &block)            
           end
         end
 
@@ -139,8 +182,8 @@ module CouchRest
             property(:created_at, Time, :read_only => true, :protected => true, :auto_validation => false)
 
             set_callback :save, :before do |object|
-              write_attribute('updated_at', Time.now)
-              write_attribute('created_at', Time.now) if object.new?
+              write_attribute_dirty('updated_at', Time.now)
+              write_attribute_dirty('created_at', Time.now) if object.new?
             end
           EOS
         end
@@ -203,7 +246,7 @@ module CouchRest
             property_name = property.name
             class_eval <<-EOS
               def #{property_name}=(value)
-                write_attribute('#{property_name}', value)
+                write_attribute_dirty('#{property_name}', value)
               end
             EOS
 
diff --git a/lib/couchrest/model/property.rb b/lib/couchrest/model/property.rb
index f08405c..2e49a00 100644
--- a/lib/couchrest/model/property.rb
+++ b/lib/couchrest/model/property.rb
@@ -40,6 +40,10 @@ module CouchRest::Model
         # allow casted_by calls to be passed up chain by wrapping in CastedArray
         value = type_class != String ? CastedArray.new(arr, self) : arr
         value.casted_by = parent if value.respond_to?(:casted_by)
+      elsif (type == Object || type == Hash) && (value.class == Hash)
+        # allow casted_by calls to be passed up chain by wrapping in CastedHash
+        value = CouchRest::Model::CastedHash[value]
+        value.casted_by = parent
       elsif !value.nil?
         value = cast_value(parent, value)
       end
diff --git a/lib/couchrest_model.rb b/lib/couchrest_model.rb
index 2e0070d..4d3e7c6 100644
--- a/lib/couchrest_model.rb
+++ b/lib/couchrest_model.rb
@@ -8,6 +8,7 @@ require "active_model/serialization"
 require "active_model/translation"
 require "active_model/validator"
 require "active_model/validations"
+require "active_model/dirty"
 
 require 'active_support/core_ext'
 require 'active_support/json'
@@ -28,8 +29,11 @@ require "couchrest/model/persistence"
 require "couchrest/model/typecast"
 require "couchrest/model/property"
 require "couchrest/model/property_protection"
-require "couchrest/model/casted_array"
 require "couchrest/model/properties"
+require "couchrest/model/dirty"
+require "couchrest/model/casted_array"
+require "couchrest/model/casted_hash"
+require "couchrest/model/casted_model"
 require "couchrest/model/validations"
 require "couchrest/model/callbacks"
 require "couchrest/model/document_queries"
diff --git a/spec/couchrest/base_spec.rb b/spec/couchrest/base_spec.rb
index d64641c..ed1ba30 100644
--- a/spec/couchrest/base_spec.rb
+++ b/spec/couchrest/base_spec.rb
@@ -372,6 +372,7 @@ describe "Model Base" do
       foundart.created_at.should == foundart.updated_at
     end
     it "should set the time on update" do
+      @art.title = "new title"  # only saved if @art.changed? == true
       @art.save
       @art.created_at.should < @art.updated_at
     end
diff --git a/spec/couchrest/dirty_spec.rb b/spec/couchrest/dirty_spec.rb
new file mode 100644
index 0000000..9184edc
--- /dev/null
+++ b/spec/couchrest/dirty_spec.rb
@@ -0,0 +1,167 @@
+require File.expand_path("../../spec_helper", __FILE__)
+
+require File.join(FIXTURE_PATH, 'more', 'cat')
+require File.join(FIXTURE_PATH, 'more', 'article')
+require File.join(FIXTURE_PATH, 'more', 'course')
+require File.join(FIXTURE_PATH, 'more', 'card')
+require File.join(FIXTURE_PATH, 'base')
+
+class WithCastedModelMixin < Hash
+  include CouchRest::Model::CastedModel
+  property :name
+  property :details, Object, :default => {}
+  property :casted_attribute, WithCastedModelMixin
+end
+
+class DummyModel < CouchRest::Model::Base
+  use_database TEST_SERVER.default_database
+  raise "Default DB not set" if TEST_SERVER.default_database.nil?
+  property :casted_attribute, WithCastedModelMixin
+  property :details, Object, :default => {}
+  property :keywords,         [String]
+  property :sub_models do |child|
+    child.property :title
+  end
+end
+
+
+describe "Dirty" do
+
+  describe "changes" do
+
+    it "should return changes on an attribute" do
+      @card = Card.new(:first_name => "matt")
+      @card.first_name = "andrew"
+      @card.changes.should == { "first_name" => ["matt", "andrew"] }
+    end
+
+  end
+
+  describe "save" do
+
+    it "should not save unchanged records" do
+      card_id = Card.create!(:first_name => "matt").id
+      @card = Card.find(card_id)
+      @card.database.should_not_receive(:save_doc)
+      @card.save
+    end
+
+    it "should save changed records" do
+      card_id = Card.create!(:first_name => "matt").id
+      @card = Card.find(card_id)
+      @card.first_name = "andrew"
+      @card.database.should_receive(:save_doc).and_return({"ok" => true})
+      @card.save
+    end
+
+  end
+
+  describe "changed?" do
+
+    # match activerecord behaviour
+    it "should report no changes on a new object with no attributes set" do
+      @card = Card.new
+      @card.changed?.should be_false
+    end
+
+=begin
+    # match activerecord behaviour
+    # not currently working - not too important
+    it "should report changes on a new object with attributes set" do
+      @card = Card.new(:first_name => "matt")
+      @card.changed?.should be_true
+    end
+=end
+
+    it "should report no changes on objects fetched from the database" do
+      card_id = Card.create!(:first_name => "matt").id
+      @card = Card.find(card_id)
+      @card.changed?.should be_false
+    end
+
+    it "should report changes if the record is modified" do
+      @card = Card.new
+      @card.first_name = "andrew"
+      @card.changed?.should be_true
+      @card.first_name_changed?.should be_true
+    end
+
+    it "should report no changes for unmodified records" do
+      card_id = Card.create!(:first_name => "matt").id
+      @card = Card.find(card_id)
+      @card.first_name = "matt"
+      @card.changed?.should be_false
+      @card.first_name_changed?.should be_false
+    end
+
+    it "should report no changes after a new record has been saved" do
+      @card = Card.new(:first_name => "matt")
+      @card.save!
+      @card.changed?.should be_false
+    end
+
+    it "should report no changes after a record has been saved" do
+      card_id = Card.create!(:first_name => "matt").id
+      @card = Card.find(card_id)
+      @card.first_name = "andrew"
+      @card.save!
+      @card.changed?.should be_false
+    end
+
+    # test changing list properties
+
+    it "should report changes if a list property is modified" do
+      cat_id = Cat.create!(:name => "Felix", :toys => [{:name => "Mouse"}]).id
+      @cat = Cat.find(cat_id)
+      @cat.toys = [{:name => "Feather"}]
+      @cat.changed?.should be_true
+    end
+
+    it "should report no changes if a list property is unmodified" do
+      cat_id = Cat.create!(:name => "Felix", :toys => [{:name => "Mouse"}]).id
+      @cat = Cat.find(cat_id)
+      @cat.toys = [{:name => "Mouse"}]  # same as original list
+      @cat.changed?.should be_false
+    end
+
+    # attachments
+
+    it "should report changes if an attachment is added" do
+      cat_id = Cat.create!(:name => "Felix", :toys => [{:name => "Mouse"}]).id
+      @file = File.open(FIXTURE_PATH + '/attachments/test.html')
+      @cat = Cat.find(cat_id)
+      @cat.create_attachment(:file => @file, :name => "my_attachment")
+      @cat.changed?.should be_true
+    end
+
+    it "should report changes if an attachment is deleted" do
+      @cat = Cat.create!(:name => "Felix", :toys => [{:name => "Mouse"}])
+      @file = File.open(FIXTURE_PATH + '/attachments/test.html')
+      @attachment_name = "my_attachment"
+      @cat.create_attachment(:file => @file, :name => @attachment_name)
+      @cat.save
+      @cat = Cat.find(@cat.id)
+      @cat.delete_attachment(@attachment_name)
+      @cat.changed?.should be_true
+    end
+
+    # casted models
+
+    it "should report changes to casted models" do
+      @cat = Cat.create!(:name => "Felix", :favorite_toy => { :name => "Mouse" })
+      @cat = Cat.find(@cat.id)
+      @cat.favorite_toy['name'] = 'Feather'
+      @cat.changed?.should be_true
+    end
+
+    it "should report changes to hashes" do
+      @obj = DummyModel.create!
+      @obj = DummyModel.get(@obj.id)
+      deets = @obj.details
+      deets['color'] = 'orange'
+      @obj.changed?.should be_true
+    end
+
+  end
+
+end
diff --git a/spec/fixtures/base.rb b/spec/fixtures/base.rb
index 34f6778..2d7e31c 100644
--- a/spec/fixtures/base.rb
+++ b/spec/fixtures/base.rb
@@ -131,7 +131,7 @@ class WithUniqueValidationView < CouchRest::Model::Base
   attr_accessor :code
   unique_id :code
   def code
-    self["_id"] ||= @code
+    @code
   end
   property :title