Add support for nested object forms to ActiveRecord and the helpers in ActionPack

Signed-Off-By: Michael Koziarski <michael@koziarski.com>

[#1202 state:committed]

1 files changed, 48 insertions, 43 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 8b51a38f48..7a88465f8c 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -88,6 +88,18 @@ module ActiveRecord
       end unless self.new_record?
     end
 
+    private
+      # Gets the specified association instance if it responds to :loaded?, nil otherwise.
+      def association_instance_get(name)
+        association = instance_variable_get("@#{name}")
+        association if association.respond_to?(:loaded?)
+      end
+
+      # Set the specified association instance.
+      def association_instance_set(name, association)
+        instance_variable_set("@#{name}", association)
+      end
+
     # Associations are a set of macro-like class methods for tying objects together through foreign keys. They express relationships like
     # "Project has one Project Manager" or "Project belongs to a Portfolio". Each macro adds a number of methods to the class which are
     # specialized according to the collection or association symbol and the options hash. It works much the same way as Ruby's own <tt>attr*</tt>
@@ -256,6 +268,10 @@ module ActiveRecord
     # You can manipulate objects and associations before they are saved to the database, but there is some special behavior you should be
     # aware of, mostly involving the saving of associated objects.
     #
+    # Unless you enable the :autosave option on a <tt>has_one</tt>, <tt>belongs_to</tt>,
+    # <tt>has_many</tt>, or <tt>has_and_belongs_to_many</tt> association,
+    # in which case the members are always saved.
+    #
     # === One-to-one associations
     #
     # * Assigning an object to a +has_one+ association automatically saves that object and the object being replaced (if there is one), in
@@ -752,6 +768,9 @@ module ActiveRecord
       #   If true, all the associated objects are readonly through the association.
       # [:validate]
       #   If false, don't validate the associated objects when saving the parent object. true by default.
+      # [:autosave]
+      #   If true, always save any loaded members and destroy members marked for destruction, when saving the parent object. Off by default.
+      #
       # Option examples:
       #   has_many :comments, :order => "posted_on"
       #   has_many :comments, :include => :author
@@ -865,6 +884,8 @@ module ActiveRecord
       #   If true, the associated object is readonly through the association.
       # [:validate]
       #   If false, don't validate the associated object when saving the parent object. +false+ by default.
+      # [:autosave]
+      #   If true, always save the associated object or destroy it if marked for destruction, when saving the parent object. Off by default.
       #
       # Option examples:
       #   has_one :credit_card, :dependent => :destroy  # destroys the associated credit card
@@ -882,13 +903,10 @@ module ActiveRecord
         else
           reflection = create_has_one_reflection(association_id, options)
 
-          ivar = "@#{reflection.name}"
-
           method_name = "has_one_after_save_for_#{reflection.name}".to_sym
           define_method(method_name) do
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
-
-            if !association.nil? && (new_record? || association.new_record? || association[reflection.primary_key_name] != id)
+            association = association_instance_get(reflection.name)
+            if association && (new_record? || association.new_record? || association[reflection.primary_key_name] != id)
               association[reflection.primary_key_name] = id
               association.save(true)
             end
@@ -979,6 +997,8 @@ module ActiveRecord
       #   If true, the associated object is readonly through the association.
       # [:validate]
       #   If false, don't validate the associated objects when saving the parent object. +false+ by default.
+      # [:autosave]
+      #   If true, always save the associated object or destroy it if marked for destruction, when saving the parent object. Off by default.
       #
       # Option examples:
       #   belongs_to :firm, :foreign_key => "client_of"
@@ -991,15 +1011,12 @@ module ActiveRecord
       def belongs_to(association_id, options = {})
         reflection = create_belongs_to_reflection(association_id, options)
 
-        ivar = "@#{reflection.name}"
-
         if reflection.options[:polymorphic]
           association_accessor_methods(reflection, BelongsToPolymorphicAssociation)
 
           method_name = "polymorphic_belongs_to_before_save_for_#{reflection.name}".to_sym
           define_method(method_name) do
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
-
+            association = association_instance_get(reflection.name)
             if association && association.target
               if association.new_record?
                 association.save(true)
@@ -1019,9 +1036,7 @@ module ActiveRecord
 
           method_name = "belongs_to_before_save_for_#{reflection.name}".to_sym
           define_method(method_name) do
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
-
-            if !association.nil?
+            if association = association_instance_get(reflection.name)
               if association.new_record?
                 association.save(true)
               end
@@ -1196,6 +1211,8 @@ module ActiveRecord
       #   If true, all the associated objects are readonly through the association.
       # [:validate]
       #   If false, don't validate the associated objects when saving the parent object. +true+ by default.
+      # [:autosave]
+      #   If true, always save any loaded members and destroy members marked for destruction, when saving the parent object. Off by default.
       #
       # Option examples:
       #   has_and_belongs_to_many :projects
@@ -1243,33 +1260,30 @@ module ActiveRecord
         end
 
         def association_accessor_methods(reflection, association_proxy_class)
-          ivar = "@#{reflection.name}"
-
           define_method(reflection.name) do |*params|
             force_reload = params.first unless params.empty?
-
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
+            association = association_instance_get(reflection.name)
 
             if association.nil? || force_reload
               association = association_proxy_class.new(self, reflection)
               retval = association.reload
               if retval.nil? and association_proxy_class == BelongsToAssociation
-                instance_variable_set(ivar, nil)
+                association_instance_set(reflection.name, nil)
                 return nil
               end
-              instance_variable_set(ivar, association)
+              association_instance_set(reflection.name, association)
             end
 
             association.target.nil? ? nil : association
           end
 
           define_method("loaded_#{reflection.name}?") do
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
+            association = association_instance_get(reflection.name)
             association && association.loaded?
           end
 
           define_method("#{reflection.name}=") do |new_value|
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
+            association = association_instance_get(reflection.name)
 
             if association.nil? || association.target != new_value
               association = association_proxy_class.new(self, reflection)
@@ -1280,7 +1294,7 @@ module ActiveRecord
               self.send(reflection.name, new_value)
             else
               association.replace(new_value)
-              instance_variable_set(ivar, new_value.nil? ? nil : association)
+              association_instance_set(reflection.name, new_value.nil? ? nil : association)
             end
           end
 
@@ -1288,20 +1302,18 @@ module ActiveRecord
             return if target.nil? and association_proxy_class == BelongsToAssociation
             association = association_proxy_class.new(self, reflection)
             association.target = target
-            instance_variable_set(ivar, association)
+            association_instance_set(reflection.name, association)
           end
         end
 
         def collection_reader_method(reflection, association_proxy_class)
           define_method(reflection.name) do |*params|
-            ivar = "@#{reflection.name}"
-
             force_reload = params.first unless params.empty?
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
+            association = association_instance_get(reflection.name)
 
-            unless association.respond_to?(:loaded?)
+            unless association
               association = association_proxy_class.new(self, reflection)
-              instance_variable_set(ivar, association)
+              association_instance_set(reflection.name, association)
             end
 
             association.reload if force_reload
@@ -1339,8 +1351,7 @@ module ActiveRecord
         def add_single_associated_validation_callbacks(association_name)
           method_name = "validate_associated_records_for_#{association_name}".to_sym
           define_method(method_name) do
-            association = instance_variable_get("@#{association_name}")
-            if !association.nil?
+            if association = association_instance_get(association_name)
               errors.add association_name unless association.target.nil? || association.valid?
             end
           end
@@ -1350,12 +1361,10 @@ module ActiveRecord
 
         def add_multiple_associated_validation_callbacks(association_name)
           method_name = "validate_associated_records_for_#{association_name}".to_sym
-          ivar = "@#{association_name}"
-
           define_method(method_name) do
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
+            association = association_instance_get(association_name)
 
-            if association.respond_to?(:loaded?)
+            if association
               if new_record?
                 association
               elsif association.loaded?
@@ -1372,8 +1381,6 @@ module ActiveRecord
         end
 
         def add_multiple_associated_save_callbacks(association_name)
-          ivar = "@#{association_name}"
-
           method_name = "before_save_associated_records_for_#{association_name}".to_sym
           define_method(method_name) do
             @new_record_before_save = new_record?
@@ -1383,13 +1390,13 @@ module ActiveRecord
 
           method_name = "after_create_or_update_associated_records_for_#{association_name}".to_sym
           define_method(method_name) do
-            association = instance_variable_get(ivar) if instance_variable_defined?(ivar)
+            association = association_instance_get(association_name)
 
             records_to_save = if @new_record_before_save
               association
-            elsif association.respond_to?(:loaded?) && association.loaded?
+            elsif association && association.loaded?
               association.select { |record| record.new_record? }
-            elsif association.respond_to?(:loaded?) && !association.loaded?
+            elsif association && !association.loaded?
               association.target.select { |record| record.new_record? }
             else
               []
@@ -1407,15 +1414,13 @@ module ActiveRecord
 
         def association_constructor_method(constructor, reflection, association_proxy_class)
           define_method("#{constructor}_#{reflection.name}") do |*params|
-            ivar = "@#{reflection.name}"
-
             attributees      = params.first unless params.empty?
             replace_existing = params[1].nil? ? true : params[1]
-            association      = instance_variable_get(ivar) if instance_variable_defined?(ivar)
+            association      = association_instance_get(reflection.name)
 
-            if association.nil?
+            unless association
               association = association_proxy_class.new(self, reflection)
-              instance_variable_set(ivar, association)
+              association_instance_set(reflection.name, association)
             end
 
             if association_proxy_class == HasOneAssociation