Rails 4: fields_for中的fields_for

Question

我正在学习RoR，我正在尝试找到如何在另一个has_one模型中设置fields_for，如下所示：

class Child < ActiveRecord::Base
    belongs_to :father
    accepts_nested_attributes_for :father
end

class Father < ActiveRecord::Base
    has_one :child
    belongs_to :grandfather
    accepts_nested_attributes_for :grandfather
end


class Grandfather < ActiveRecord::Base
    has_one :father
end

我在铁路广播上使用了嵌套模型表单的第1部分来获得这些:在children_controller.rb中：

  def new
    @child = Child.new
    father=@child.build_father
    father.build_grandfather
  end

def child_params
      params.require(:child).permit(:name, father_attributes:[:name], grandfather_attributes:[:name])
    end

我的表格是：

<%= form_for(@child) do |f| %>
  <div class="field">
    <%= f.label :name %><br>
    <%= f.text_field :name %>
  </div>
  mother:<br>
  <%= f.fields_for :father do |ff| %>
    <%= ff.label :name %>
    <%= ff.text_field :name %><br>
      grand mother:<br>
      <%= f.fields_for :grandfather do |fff| %>
        <%= fff.label :name %>
        <%= fff.text_field :name %>
      <% end %>
  <% end %>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

我正在尝试使用以下命令检索数据：

<%= child.father.name %>
<%= child.father.grandfather.name %>

但是外公的名字不会起作用。我找不到错误的...anyone来帮助解决此问题？谢谢!

Answer 1

尝试切换：

<%= f.fields_for :grandfather do |fff| %>

至：

<%= ff.fields_for :grandfather do |fff| %>

和交换：

params.require(:child).permit(:name, father_attributes:[:name], grandfather_attributes:[:name])

至：

params.require(:child).permit(:name, father_attributes:[:name, grandfather_attributes:[:name]])