Counter on model

Question

I’m looking for a way to add an incremented variable to the id of a div, could someone tell me the most recommended way to do this?

my difficulty in making this increment is due to the Cocoon that is used to call this render

<%= link_to_add_association '+', f, :filtro_questoes,
        'data-association-insertion-node' => "#filter_q",
        'data-association-insertion-method' => "append", id: 'add', class: 'btn btn-primary' %>

have already accessed object attribute <%= f. Count %>, @Count, but nothing worked out

Obs: If you have a better way to do this without calling the model attribute you’re also worth =D

I need to improve my knowledge in Ruby, but I have to finish soon what I’m doing.

model

class Carro < ActiveRecord::Base
    attr_accessor :count

    belongs_to :person

    def self.count(n = 0)
        @count = n+1
    end

    def self.count
        @count
    end

end

view

<div class="control-group nested-fields">

    <div id="carro_div_n <%= f.count %>" class="row form-group" style="border: 1px solid blue; padding: 10px; margin: 10px;">
      <div class="field">
        <h3>Descrição...</h3>
        <%= f.label :carro_id %>
      </div>

      <div class="field col-xs-3">
        <%= f.label :marca_id %>
        <%= f.select :marca_id, 
        options_for_select(
          @marcas.collect { |marca|
          [marca.name.titleize, marca.id] }, 0), {prompt: 'Selecionar marca'}, { id: 'marcas_select', class: 'form-control'} %>
      </div>
      <div id="div_modelo_n" class="field col-xs-3">
        <%= f.label :modelo_id %>
      <%= f.select :modelo_id, options_for_select(@modelos.collect { |modelo|
          [modelo.name.titleize, modelo.id] }, 0), {}, { id: 'modelos_select', class: 'form-control' } %>
      </div>
      <div class="checkbox form-group col-xs-2">
        <%= link_to_remove_association "remove tarefa", f, class: 'btn btn-danger' %>
      </div>
    </div>
</div>

Answer 1

First thing, when you insert the self It is a method he turns into a static method, static in the Java, that is, you should call it so: Carro.count.

If you want an id, simply use the id of the car: Carro.id

But if you really want to count, do it when showing all the cars. For example if you are using a each to show all cars:

<% Carro.all.each_with_index do |carro, count| %>
    <div id="<%= carro.count %>">
        ...
    </div>
<% end %>

Answer 2

Have you tried instead of <%= f.count %> use <%= @carro.count %> ?