importing untested concept code

README

@@ -1,9 +1,8 @@
-NestedAssignment
-================
+= NestedAssignment
 
 An attempt at solving the model (and controller) side of nested forms. Based on thoughts pulled from http://groups.google.com/group/rubyonrails-core/browse_thread/thread/4049b4b313fa8be2, http://groups.google.com/group/rubyonrails-core/browse_thread/thread/3c61e00916c365e5/f0a19fc01d0246fc, and work on ActiveScaffold.
 
-Goals:
+== Goals:
 
 # Assigning attributes should remain in-memory. Nothing should be permanent before #save. This means avoiding some of ActiveRecord's association assignment logic such as AssociationCollection#replace.
 # Deep and thorough validation of all new and changed associated records. In order for all possible errors to be available at once, no single invalid record may halt the process.
@@ -16,4 +15,16 @@ and of course:
 
 # Skinny controllers. There's no footprint in the controller, actually.
 
+== Paradigm Params (cf http://gist.github.com/10793)
+
+  {
+    :task_params =>
+      {
+        '1' => { :id => '3', :name => "Foo" },
+        '2' => { :id => '5', :name => "Bar", :_delete => true}
+        '3' => { :name => "Baz" }
+      }
+  }
+
+
 Copyright (c) 2008 Lance Ivy, released under the MIT license

lib/nested_assignment.rb

@@ -1 +1,68 @@
 # NestedAssignment
+module NestedAssignment
+  def self.included(base)
+    base.class_eval do extend ClassMethods end
+  end
+
+  module ClassMethods
+    # Parallels attr_accessible. Could easily trigger from :accessible => true instead.
+    def accessible_associations(*associations)
+      associations.each do |name|
+
+        define_method("#{name}_params=") do |hash|
+          assoc = self.send(name)
+          hash.values.each do |row|
+            record = row[:id].blank? ? assoc.build : assoc.select{|r| r.id == row[:id].to_i}
+            if row[:_delete]
+              record._delete = true
+            else
+              record.attributes = row
+            end
+          end
+        end
+
+      end
+    end
+
+    protected
+
+    def self.association_names
+      @association_names ||= reflect_on_all_associations.map(&:name)
+    end
+  end
+
+  # marks the record to be deleted in the next save
+  attr_accessor :_delete
+
+  # deep validation of any changed (or new) records.
+  # makes sure that any single invalid record will not halt the
+  # validation process, so that all errors will be available
+  # afterwards.
+  def valid?
+    [changed_associated.all?(&:valid?), super].all?
+  end
+
+  # deep saving of any new, changed, or deleted records.
+  def save
+    self.class.transaction do
+      super
+      changed_associated.each(&:save)
+      deletable_associated.each(&:destroy)
+    end
+  end
+
+  protected
+
+  def deletable_associated
+    instantiated_associated.select(&:_delete)
+  end
+
+  def changed_associated
+    instantiated_associated.select(&:changed?
+  end
+
+  def instantiated_associated
+    self.class.associations_names.collect{ |name| [self.send(name).target] }.flatten
+  end
+
+end

test/nested_assignment_test.rb

@@ -1,8 +1,5 @@
 require 'test_helper'
 
 class NestedAssignmentTest < ActiveSupport::TestCase
-  # Replace this with your real tests.
-  test "the truth" do
-    assert true
-  end
+
 end