activerecord - What is the Correct Ruby on Rails Syntax to Write to a Nested Model within a Virtual Attribute? -

trying divide , conquer these problems (1, 2) still having. write first step of blt recipe in nested, many-to-many model virtual attribute. later on have more complex form, doing in model.

i have hard-coded in model except name of recipe. here recipe model:

    class recipe < activerecord::base       has_many :steps, :class_name => 'step'       has_many :stepingreds, :through => :steps       has_many :ingredients, :through => :stepingreds       accepts_nested_attributes_for :steps, :stepingreds, :ingredients       attr_writer :name_string       after_save :assign_name        def name_string         self[:name]       end        def assign_name         if @name_string         self[:name] = @name_string         self[:description] = "addictive sandwich"         self.steps = step.create({            :number => 1,            :instructions => 'cook bacon',            :stepingreds => [{ :ingredient => { :name => 'bacon' }, :amount => 4 } ]           })        end     end 

and here form

    <%= form_for @recipe |f| %>         <%= f.error_messages %>         <p>           <%= f.label :name_string, "name" %><br/>           <%= f.text_field :name_string %>         </p>         <p><%= f.submit %></p>     <% end %> 

i "nameerror in recipescontroller#create, undefined local variable or method `attribute' #". think have more 1 error seems should work me. doing wrong?

thanks!

edit - here recipecontroller create action

   def create        @recipe = recipe.new(params[:recipe])        if @recipe.save          redirect_to @recipe, :notice => "delicious blt created!"        else          render :action => 'new'        end      end                 

here's simple rails application need:

https://github.com/pixeltrix/cookbook