added support for simple_form

.gitignore

@@ -3,3 +3,5 @@
 *.gem
 Gemfile.lock
 .bundle
+Gemfile
+log

Gemfile → Gemfile-base

@@ -1,3 +1,2 @@
 source "http://rubygems.org"
-
 gemspec

Gemfile-simple_form

@@ -0,0 +1,3 @@
+source "http://rubygems.org"
+gemspec
+gem 'simple_form'

Rakefile

@@ -2,9 +2,26 @@ require 'rubygems'
 require 'rake'
 require 'rspec/core/rake_task'
 
+task :spec do
+  `rm Gemfile` if File.exists?('./Gemfile')
+  `cp Gemfile-base Gemfile`
+  `bundle install`
+end
+
+task :simple_form_spec do
+  `rm Gemfile` if File.exists?('./Gemfile')
+  `cp Gemfile-simple_form Gemfile`
+  `bundle install`
+end
+
 desc "Run RSpec"
 RSpec::Core::RakeTask.new do |t|
   t.verbose = false
 end
 
-task :default => :spec
+desc "Run RSpec for SimpleForm Gemfile"
+RSpec::Core::RakeTask.new(:simple_form_spec) do |t|
+  t.verbose = false
+end
+
+task :default => [:spec, :simple_form_spec]

lib/nested_form/builder.rb

@@ -1,5 +1,14 @@
 module NestedForm
-  class Builder < ::ActionView::Helpers::FormBuilder
+  def self.base_builder_class
+    begin
+      require 'simple_form'
+      ::SimpleForm::FormBuilder
+    rescue LoadError
+      ::ActionView::Helpers::FormBuilder
+    end
+  end
+
+  class Builder < base_builder_class
     # Adds a link to insert a new associated records. The first argument is the name of the link, the second is the name of the association.
     #
     #   f.link_to_add("Add Task", :tasks)