如何以嵌套的形式获取子项的索引

Question

在Rails 3.2应用程序中,我使用简单表单来创建复杂的表单.

表单/模型accepts_nested_attributes_for,我需要获取子对象的索引.

型号:

class Project
  has_many :tasks
  accepts_nested_attributes_for :tasks
end

class Task
  belongs_to :project
end

表格

<%= simple_form_for @project do |f| %>
  <%= f.simple_fields_for :tasks do |builder| %>
    ## I need to get the index of each object built via builder
  <% end %>
<% end %>

我如何正确获取索引？

Answer 1

你可以用这个:

<%= simple_form_for @project do |f| %>
    <%= f.simple_fields_for :tasks do |builder| %>
        <%= builder.index %>
    <% end %>
<% end %>