Create Related Data using Nested attributes - ruby

Question

api. Now need to insert a record which has associated records. I read nested attributes but didn't get any idea. I can't understand well.
I tried with one example in rails mvc project but even i can't create associated record in one-one mapping itself. Please guid me what the steps to do this or any good articles with sample?
Anyway the following is my workings
My model is
class Instructor < ActiveRecord::Base
has_one :office_assignment
has_many :departments
has_and_belongs_to_many :courses
accepts_nested_attributes_for :office_assignment
end
class OfficeAssignment < ActiveRecord::Base
belongs_to :instructor
end
My controller methods for create
def new
#instructor = Instructor.new
end
def create
#instructor = Instructor.new(instructor_params)
respond_to do |format|
if #instructor.save
format.html { redirect_to #instructor, notice: 'Instructor was successfully created.' }
format.json { render :show, status: :created, location: #instructor }
else
format.html { render :new }
format.json { render json: #instructor.errors, status: :unprocessable_entity }
end
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_instructor
#instructor = Instructor.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def instructor_params
params.require(:instructor).permit(:LastName, :FirstMidName, :HireDate, office_assignment_attributes: [:Location])
end
My create form
<%= form_for #instructor, :html => { :class => "form-horizontal instructor" } do |f| %>
<% if #instructor.errors.any? %>
<div id="error_expl" class="panel panel-danger">
<div class="panel-heading">
<h3 class="panel-title"><%= pluralize(#instructor.errors.count, "error") %> prohibited this instructor from being saved:</h3>
</div>
<div class="panel-body">
<ul>
<% #instructor.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
</div>
<% end %>
<div class="form-group">
<%= f.label :LastName, :class => 'control-label' %>
<div class="controls">
<%= f.text_field :LastName, :class => 'form-control' %>
</div>
<%= error_span(#instructor[:LastName]) %>
</div>
<div class="form-group">
<%= f.label :FirstMidName, :class => 'control-label' %>
<div class="controls">
<%= f.text_field :FirstMidName, :class => 'form-control' %>
</div>
<%= error_span(#instructor[:FirstMidName]) %>
</div>
<div class="form-group">
<%= f.label :HireDate, :class => 'control-label' %>
<div class="controls">
<%= f.text_field :HireDate, :class => 'form-control' %>
</div>
<%= error_span(#instructor[:HireDate]) %>
</div>
<div class="form-group">
<%= f.label :Location, :class => 'control-label' %>
<div class="controls">
<input type="text" name="office_assignment_Location" class ="form-control">
</div>
<%= error_span(#instructor[:HireDate]) %>
</div>
<%= f.submit nil, :class => 'btn btn-primary' %>
<%= link_to t('.cancel', :default => t("helpers.links.cancel")),
instructors_path, :class => 'btn btn-default' %>
<% end %>
Please guide me..
Edit:
Changes in html file
<%= f.fields_for :office_assignment_Location do |loc| %>
<div class="form-group">
<%= loc.label :Location, :class => 'control-label' %>
<div class="controls">
<%= loc.text_field :Location %>
</div>
</div>
<%= loc.link_to_add "Add Location", :office_assignment_Location , :class=>'btn btn-primary'%>
<% end %>
My param in controller
def instructor_params
params.require(:instructor).permit(:LastName, :FirstMidName, :HireDate, office_assignment_attributes: [:id, :Location ,:_destroy])
end
My schema
create_table "instructors", force: :cascade do |t|
t.string "LastName", limit: 255
t.string "FirstMidName", limit: 255
t.date "HireDate"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "office_assignments", primary_key: "Instructor_Id", force: :cascade do |t|
t.string "Location", limit: 255
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
add_foreign_key "office_assignments", "instructors", column: "Instructor_Id"

Answer 1

FYI: attribute's name should start with small letter not capital.
Here are some changes:
class Instructor < ActiveRecord::Base
has_one :office_assignment , :dependent => :destroy # add dependent destroy
has_many :departments
has_and_belongs_to_many :courses
accepts_nested_attributes_for :office_assignment, :reject_if => :all_blank, :allow_destroy => true # add allow destroy
end
Some change in strong Parameters:
def instructor_params
params.require(:instructor).permit(:LastName, :FirstMidName, :HireDate, office_assignment_attributes: [:id, :Lesson ,:_destroy])
end
Note: Don't forget to add :id and :_destroy in office_assignment_attributes
Now in View(form_template):
Instead of this:
<div class="form-group">
<%= f.label :Location, :class => 'control-label' %>
<div class="controls">
<input type="text" name="office_assignment_Location" class ="form-control">
</div>
<%= error_span(#instructor[:HireDate]) %>
</div>
It should be:
<%= nested_form_for #instructor, :html => { :class => "form-horizontal instructor" } do |f| %>
......
.....
<%= f.fields_for :office_assignment do |loc| %>
<div class="form-group">
<%= loc.label :Location, :class => 'control-label' %>
<div class="controls">
<%= loc.text_field :Location %>
</div>
</div>
<% end %>
<%= f.link_to_add "Add Location", :office_assignment , :class=>'btn btn-primary'%>
You have to create nested form like this. I hope this helps you.
Note: Use nested_form_for instead of form_for in your form:
For your reference:
http://railscasts.com/episodes/196-nested-model-form-part-1
http://railscasts.com/episodes/197-nested-model-form-part-2