Dirty tracking refactor

README.md

@@ -19,6 +19,8 @@ See the [update history](https://github.com/couchrest/couchrest_model/blob/maste
 
 ### Upgrading from an earlier version?
 
+*Pre 2.2:* As of August 2016, dirty tracking has been radically re-factored away from ActiveModel::Dirty, which only has support for basic attributes, into a solution that uses [Hashdiff](https://github.com/liufengyun/hashdiff), more details available in the [pull request](https://github.com/couchrest/couchrest_model/pull/211). The result is that some of ActiveModel's Dirty methods are no longer available, these are: `changes_applied`, `restore_attributes`, `previous_changes`, and `changed_attributes`.
+
 *Pre 2.0:* As of June 2012, couchrest model no longer supports the `view_by` and `view` calls from the model. Views are no only accessed via a design document. If you have older code and wish to upgrade, please ensure you move to the new syntax for using views.
 
 *Pre 1.1:* As of April 2011 and the release of version 1.1.0, the default model type key is 'type' instead of 'couchrest-type'. Simply updating your project will not work unless you migrate your data or set the configuration option in your initializers:

VERSION

@@ -1 +1 @@
-2.1.0.rc1
+2.2.0.beta

couchrest_model.gemspec

@@ -25,6 +25,7 @@ Gem::Specification.new do |s|
   s.add_dependency("couchrest",   "2.0.0")
   s.add_dependency("activemodel", "~> 4.0")
   s.add_dependency("tzinfo",      ">= 0.3.22")
+  s.add_dependency("hashdiff",    "~> 0.3")
   s.add_development_dependency("rspec", "~> 2.14.1")
   s.add_development_dependency("rack-test", ">= 0.5.7")
   s.add_development_dependency("rake", ">= 0.8.0")

history.md

@@ -1,6 +1,10 @@
 # CouchRest Model Change History
 
-## 2.1.0 - 2016-07-06
+## 2.2.0.beta1 - pending
+
+  * Radical re-factor of dirty tracking using Hashdiff gem, providing reliable change detection with nested data. [PR](https://github.com/couchrest/couchrest_model/pull/211) (@samlown)
+
+## 2.1.0.rc1 - 2016-07-06
 
   * Adding "persistent" connection configuration property (@samlown)
   * Releasing 2.1.0 off of CouchRest 2.0.0.

lib/couchrest/model/associations.rb

@@ -1,12 +1,8 @@
 module CouchRest
   module Model
+    # Basic support for relationships between CouchRest::Model::Base
     module Associations
-
-      # Basic support for relationships between CouchRest::Model::Base
-
-      def self.included(base)
-        base.extend(ClassMethods)
-      end
+      extend ActiveSupport::Concern
 
       module ClassMethods
 
@@ -240,8 +236,7 @@ def check_obj(obj)
 
       # Override CastedArray instantiation_and_cast method for a simpler
       # version that will not try to cast the model.
-      def instantiate_and_cast(obj, change = true)
-        couchrest_parent_will_change! if change && use_dirty?
+      def instantiate_and_cast(obj)
         obj.casted_by = casted_by if obj.respond_to?(:casted_by)
         obj.casted_by_property = casted_by_property if obj.respond_to?(:casted_by_property)
         obj

lib/couchrest/model/base.rb

@@ -45,26 +45,34 @@ def self.inherited(subklass)
       #
       # Options supported:
       #
-      # * :directly_set_attributes, true when data comes directly from database
+      # * :write_all_attributes, true when data comes directly from database so we can set protected and read-only attributes.
       # * :database, provide an alternative database
       #
       # If a block is provided the new model will be passed into the
       # block so that it can be populated.
-      def initialize(attributes = {}, options = {})
+      def initialize(attributes = {}, options = {}, &block)
         super()
-        prepare_all_attributes(attributes, options)
-        # set the instance's database, if provided
+
+        # Always force the type of model
+        self[self.model_type_key] = self.class.model_type_value
+
+        # Some instances may require a different database
         self.database = options[:database] unless options[:database].nil?
-        unless self['_id'] && self['_rev']
-          self[self.model_type_key] = self.class.model_type_value
-        end
+
+        # Deal with the attributes
+        write_attributes_for_initialization(attributes, options)
 
         yield self if block_given?
 
         after_initialize if respond_to?(:after_initialize)
         run_callbacks(:initialize) { self }
       end
 
+      def self.build(attrs = {}, options = {}, &block)
+
+
+      end
+
       alias :new_record? :new?
       alias :new_document? :new?
 

lib/couchrest/model/casted_array.rb

@@ -5,6 +5,7 @@
 
 module CouchRest::Model
   class CastedArray < Array
+    include CouchRest::Model::Configuration
     include CouchRest::Model::CastedBy
     include CouchRest::Model::Dirty
     attr_accessor :casted_by_property
@@ -30,42 +31,15 @@ def unshift(obj)
     end
 
     def []= index, obj
-      value = instantiate_and_cast(obj, false)
-      couchrest_parent_will_change! if use_dirty? && value != self[index]
+      value = instantiate_and_cast(obj)
       super(index, value)
     end
 
     def insert index, *args
-      values = *args.map{|obj| instantiate_and_cast(obj, false)}
-      couchrest_parent_will_change! if use_dirty?
+      values = *args.map{|obj| instantiate_and_cast(obj)}
       super(index, *values)
     end
 
-    def pop
-      couchrest_parent_will_change! if use_dirty? && self.length > 0
-      super
-    end
-
-    def shift
-      couchrest_parent_will_change! if use_dirty? && self.length > 0
-      super
-    end
-
-    def clear
-      couchrest_parent_will_change! if use_dirty? && self.length > 0
-      super
-    end
-
-    def delete(obj)
-      couchrest_parent_will_change! if use_dirty? && self.length > 0
-      super(obj)
-    end
-
-    def delete_at(index)
-      couchrest_parent_will_change! if use_dirty? && self.length > 0
-      super(index)
-    end
-
     def build(*args)
       obj = casted_by_property.build(*args)
       self.push(obj)
@@ -76,11 +50,26 @@ def as_couch_json
       map{ |v| (v.respond_to?(:as_couch_json) ? v.as_couch_json : v)}
     end
 
+    # Overwrite the standard dirty tracking clearing.
+    # We don't have any properties, but we do need to check
+    # entries in our array.
+    def clear_changes_information
+      if use_dirty?
+        each do |val|
+          if val.respond_to?(:clear_changes_information)
+            val.clear_changes_information
+          end
+        end
+        @original_change_data = current_change_data
+      else
+        @original_change_data = nil
+      end
+    end
+
     protected
 
-    def instantiate_and_cast(obj, change = true)
+    def instantiate_and_cast(obj)
       property = casted_by_property
-      couchrest_parent_will_change! if change && use_dirty?
       if casted_by && property && obj.class != property.type
         property.cast_value(casted_by, obj)
       else

lib/couchrest/model/configuration.rb

@@ -15,12 +15,14 @@ module Configuration
         add_config :connection
         add_config :connection_config_file
         add_config :time_fraction_digits
+        add_config :disable_dirty_tracking
 
         configure do |config|
           config.model_type_key = 'type' # was 'couchrest-type'
           config.mass_assign_any_attribute = false
           config.auto_update_design_doc = true
           config.time_fraction_digits = 3
+          config.disable_dirty_tracking = false
 
           config.environment = :development
           config.connection_config_file = File.join(Dir.pwd, 'config', 'couchdb.yml')