How to display validation errors when using nested forms? - ruby-on-rails

Question

First of all sorry about my English and about my knowledge of Rails, I am beginner who just started.
I have 2 models with relations:
CargoItems:
class CargoItem < ActiveRecord::Base
belongs_to :cargo
attr_accessible :cargo_id, :height, :length, :pieces, :weight, :width
validates :cargo, :height, :length, :width, :weight, :pieces, presence: true
validates :height, :length, :width, :pieces, numericality: { only_integer: true, greater_than_or_equal_to: 1}
validates :weight, numericality: { only_integer: true, greater_than_or_equal_to: 100}
end
Cargos:
class Cargo < ActiveRecord::Base
belongs_to :airport
belongs_to :user
belongs_to :cargo_state
belongs_to :cargo_price
belongs_to :cargo_description
has_many :cargo_items, :inverse_of => :cargo, :dependent => :destroy
attr_accessible :departure_date, :cargo_state_id, :airport_id, :cargo_price_id, :cargo_description_id, :cargo_items_attributes
accepts_nested_attributes_for :cargo_items, :allow_destroy => true, :reject_if => :all_blank
validates_associated :cargo_items
validates :departure_date, :cargo_state, :airport, :cargo_price, :cargo_description, presence: true
validates :departure_date, date: { after: Proc.new { Date.today - 1.day }, before: Proc.new { Time.now + 1.year } }, :on => :create
default_scope :order => 'departure_date DESC'
end
I use following GEMs: simple_forms, nested_forms. This is form to add new Cargo with multiple CargoItems (they have possibility to be added dynamically) belonging to Cargos:
<%= simple_nested_form_for #cargo, :wrapper => false do |f| %>
<%= f.association :airport, :label_method => :full_airport_name, :value_method => :id , :order => :iata_code %>
<%= f.input :departure_date , as: :date, start_year: Date.today.year,
end_year: Date.today.year + 16,
order: [:day, :month, :year] %>
<%= f.association :cargo_description, :label_method => :description, :value_method => :id, :order => :description %>
<%= f.association :cargo_price, :label_method => :price, :value_method => :id %>
<%= f.association :cargo_state, :label_method => :state, :value_method => :id %>
<hr>
<table>
<tr>
<th><%= :length %></th>
<th><%= :width %></th>
<th><%= :height %></th>
<th><%= :weight %></th>
<th><%= :pieces %></th>
</tr>
<%= f.simple_fields_for :cargo_items, #cargo_item do |cargo_items_fields| %>
<tr class="fields">
<td><%= cargo_items_fields.text_field :length %></td>
<td><%= cargo_items_fields.text_field :width %></td>
<td><%= cargo_items_fields.text_field :height %></td>
<td><%= cargo_items_fields.text_field :weight %></td>
<td><%= cargo_items_fields.text_field :pieces %></td>
<td><%= cargo_items_fields.link_to_remove "Remove this item", :confirm => 'Are you sure you want to remove this item?' %></td>
</tr>
<% end %>
</table>
<%= f.link_to_add "Add a item", :cargo_items %>
<div class="actions">
<%= f.button :submit %>
</div>
<% end %>
Cargo controller:
def new
#cargo = Cargo.new
#cargo_item = CargoItem.new
respond_to do |format|
format.html # new.html.erb
format.json { render json: #cargo }
end
end
def create
#cargo = Cargo.new(params[:cargo])
#cargo.user_id = current_user[:id]
respond_to do |format|
if #cargo.save
format.html { redirect_to #cargo, notice: 'Cargo was successfully created.' }
format.json { render json: #cargo, status: :created, location: #cargo }
else
format.html { render action: "new" }
format.json { render json: #cargo.errors, status: :unprocessable_entity }
end
end
end
My problem is, validation errors are not shown for CargoItems, model is actually validating. I am not able to save Cargos with CargoItems which does not fulfill validating rules. But in case validations are not met, Cargo is not saved and it just stayed on the same page without any notification that CargoItems fields are invalid. Cargos fields validation errors are shown properly.
Thanx a lot for helping me.

Answer 1

You need to add this errors notication before your form. Take a look at mine for example
<% if #author.errors.any? %>
<div class="alert alert-block">
<ul>
<% #author.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<% if #book.errors.any? %>
<div class="alert alert-block">
<ul>
<% #book.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<%= form_for([#author, #book], html: { class: "well" }) do |f| %>
#labels and buttons...
<% end %>
I have an Author who has many Books, like so:
Author:
class Author < ActiveRecord::Base
attr_accessible :name
has_many :books, dependent: :destroy
accepts_nested_attributes_for :books, allow_destroy: true
validates :name, presence: true
validates :name, length: { minimum: 3 }
end
Book:
class Book < ActiveRecord::Base
attr_accessible :name, :year
belongs_to :author
validates :name, :year, presence: true
validates :year, numericality: { only_integer: true, less_than_or_equal_to: Time.now.year }
end

Answer 2

Simple Form also allows you to use label, hint, input_field, error and full_error helpers. for more detail documentation --> https://github.com/plataformatec/simple_form
Example code with error,
<%= simple_form_for #user do |f| %>
<%= f.label :username %>
<%= f.input_field :username %>
<%= f.hint 'No special characters, please!' %>
<%= f.error :username, id: 'user_name_error' %>
<%= f.full_error :token %>
<%= f.submit 'Save' %>
<% end %>