How to create nested model form

Question

I am just not to sure how to build a nested form. I have followed Ryan Railscasts but I am unsure on how to create a new instance in my case.

I have the following models

Customer,
Book Manager, and
Book

The relationship his has follow

Customer
    has_many :book_managers, :dependent => :destroy
    accepts_nested_attributes_for :book_managers
Book
    belongs_to :book_manager
    def customer
        book_manager.customer
    end
Book_Manager
    belongs_to :customer
    has_many :books, :dependent => :destroy

The form his has follow

<%= form_for @bookmanager do |f| %>
  <%= f.fields_for :books, Book.new do |builder| %>
  <div>
    <%= builder.label :description %><br />
    <%= builder.text_area :description, :rows => 3 %>
  </div>
  <% end %>
  <div class="field">  
    <%= f.label :visible %><br />  
    <%= f.text_field :visible %>  
  </div>  
  <div class="actions">
    <%= f.submit %>
  </div>  
<% end %>

The part that confused me his to create a new instance in the single form. I have a description which belongs to book and I have a isVisible who belongs to book_managers

Here what i am thinking but doesn't seem to be working

@customer = Customer.find(params[:id])
@bookmanager = BookManager.new(params[:bookmanager])
@book = Book.new(params[:book])

I also try the following

@customer = Customer.find(params[:id])
@bookmanager = @customer.book_managers.build

It doesn't work and not sure how to create the relationship. Any help on it is appreciated!

Here the query i did In rails c

cust = Customer.first
cust.book_managers.build :visible => true
cust.book_managers.first.books.build :description => 'the odyssey'
cust.save!

Seem okay then i did the follow to check

cust = Customer.find 1
cust.books              ### This is where the error was given to me
Book.first.customer

The error is

NoMethodError: undefined method `books' for #<Customer:0xad55afc>

Following Railscasts Tutorial I should not add a relationship from customer -> books. But many other people seem to suggest to do so with has_many. What his the best way, How should i create a new item. I am very confused on how ruby acts. — Jseb
– Jseb, Commented Aug 3, 2012 at 14:13
If you need to have something like: cust = Customer.find(1), cust.books You need to have in your Customer model a has_many :books relashionship. — MurifoX
– MurifoX, Commented Aug 3, 2012 at 14:31
That would resolve my console issues, but it doesn't resolve the creation of books and book_manager in one form. How could i do this? — Jseb
– Jseb, Commented Aug 3, 2012 at 14:33

Supportie · Accepted Answer · 2013-02-21 05:22:55Z

1

You should use a has_many: through: relationship

class Customer < ActiveRecord::Base
  has_many :book_managers, :dependent => :destroy
  has_many :books, :through => :book_managers
  accepts_nested_attributes_for :book_managers
end

class BookManager < ActiveRecord::Base
  belongs_to :customer
  has_many :books, :dependent => :destroy
end

class Book < ActiveRecord::Base
  has_many :book_manager
  def customer
    book_manager.customer
  end
end

You can read more http://guides.rubyonrails.org/association_basics.html#choosing-between-has_many-through-and-has_and_belongs_to_many

answered Feb 21, 2013 at 5:22

Supportie

1811 silver badge6 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to create nested model form

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related