Editing associated models the rails way - ruby-on-rails

Question

I have a model "Student" and every student has_many parents (a mother and a father in the parents table). In my UI I want to be able to add the parents and the student on the same page. So when I click on "Add student" the view 'students/new' is rendered. In this view I have the regular stuff for adding a student (<% form_for #student....) so far so good. But now I also want to provide the form for adding a mother and a father for this student on the same page. I know I could place a link to 'parents/new' somewhere but that is not really user-friendly in my opinion.
What are my options and what would you recommend?

Answer 1

Your best bet would be using nested_forms with accepts_nested_attributes_for like below
#student.rb
Class Student < ActiveRecord::Base
has_many :parents
accepts_nested_attributes_for :parents
end
#students_controller.rb
def new
#student = Student.new
#student.parents.build
end
def create
#student = Student.new(student_params)
if #student.save
redirect_to #student
else
render 'new'
end
private
def student_params
params.require(:student).permit(:id, :student_attr_1, :student_attrr_2, parents_attributes: [:id, :father, :mother])
end
#students/new
<%= form_for #student do |f| %>
---student code here ---
<%= f.fields_for :parents do |p| %>
<%= p.label :father, :class => "control-label" %>
<%= p.text_field :father %>
<%= p.label :fmother, :class => "control-label" %>
<%= p.text_field :mother %>
<% end %>

Answer 2

Inside your form you can add fields_for helper
<%= fields_for #student.father do |father| %>
<% father.text_field :name %> # will be appropriate father name
....
<% end %>
Check also rails fields_for

Answer 3

I'd use the ObjectForm concept:
Here is one good article about this pattern.
Here's an introduction to the implementation:
Class Student < ActiveRecord::Base
has_many :parents
end
class CompleteStudentForm
include ActiveModel::Model
attr_acessor :name, :age #student attributes
attr_accessor :father_name, :mother_name #assuming that Parent model has only the :name attribute
validates_presence_of :name, :age
# simply add custom validation messages for fields
validates_presence_of :father_name, message: 'Fill your father name'
validates_presence_of :mother_name, message: 'Fill your mother name'
def save
persist! if valid?
end
private
def persist!
student = Student.new(name: #name, age: #age)
student.parents << Parent.new(name: #father_name)
student.parents << Parent.new(name: #mother_name)
student.save!
end
end
class StudentController
def create
#student = CompleteStudentForm.new(params[:complete_student_form])
if #student.save
redirect_to :show, #student
else
render :new
end
end
end