Question

I’m new to rails and just cant get that problem solved.

i have 3 models. Orders, Products and LineItems.
I want to have a order form with checkboxes for each product. User selects appropriate products and submits the order.

I cannot get the form to create the correct hash.

class Order < ActiveRecord::Base
  attr_accessible :account_id, :user_id

  has_many :line_items, :dependent => :destroy
end

class LineItem < ActiveRecord::Base
  attr_accessible :account_id, :product_id, :order_id

  belongs_to :orders
  belongs_to :product
end

Here the view:

<%= form_for 'line_items[]' do |f|  %>
   <%= f.select :account_id, options_from_collection_for_select( Account.all, 
       :id, :name ), :prompt => 'Select Account' %>

<% Product.all.each do |product| %>
<div>
       <%= check_box_tag 'line_items[product_ids][]', product.id %>
</div>
<% end -%>

    <div>       
    <%= f.submit 'save' %>
</div>

thanks!

Answer 1

You would need to use accepts_nested_attributes_for in your model to enable nested atributes from associated models. You may also want to check out this railscast and adapt to your needs.

For example in the orders model:

class Order < ActiveRecord::Base
  attr_accessible :account_id, :user_id

  has_many :products #This makes the association to products
  has_many :line_items, :dependent => :destroy

  accepts_nested_attributes_for :products #This allows the attributes from products accessible
end

Then the form could be:

<%= form_for @order do |f| %>

  <%= f.select :account_id, options_from_collection_for_select( Account.all, 
       :id, :name ), :prompt => 'Select Account' %>

  <%= f.fields_for :product do |product_form| %>
    <%= product_form.check_box :id  %>
  <% end %>

  <%= f.submit %>
<% end %>