ruby on rails - Adding only one record with nested attributes that is a has_many relationship -

i have been googling around day, , google-fu has seemed fail me. trying add/update single record has has_many relationship through nested attributes.

models:

class employee   has_many :courses   accepts_nested_attributes_for :courses, reject_if: :all_blank   validates_associated :courses end  class course   belongs_to :employee   validates :class_name, presence: true, length: { maximum: 60 }   validates :class_date, presence: true end 

controller:

def update   @employee = employee.find(params[:id])   #...   @employee.update_attributes(employee_params)   #... end  def employee_params   params.require(:employee).permit(..., courses_attributes: [ :class_name, :class_date ]) end 

view:

<%= empform.fields_for :courses |f| %>   <%= f.label :class_name, "class name:" %>   <%= f.text_field :class_name %><br />   <%= f.label :class_date, "class date:" %>   <%= f.text_field :class_date %> <% end %> 

the issue above code lists associated courses employee. not want. can do:

<%= empform.fields_for :courses, course.new |f| %>     <!-- ... --> <% end %> 

and display 1 field, , seems work far saving value db. however, if enter invalid data, validations fail. contents of text_field's empty. (because object new record , not invalid record.)

so, like:

controller:

def edit   # ...   @course = course.new end  def update   @employee = employee.find(params[:id])   @employee.update_attributes(employee_params)   @course = @employee.courses.last if @employee.courses.last.new_record? end 

then in view

<%= empform.fields_for :courses, @course %>   <!-- .... --> <% end %> 

but feels bit kludgy. guess wondering cleanest method/correct way is?