Ruby-on-rails Rails 4：fields_for 中的 fields_for
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Rails 4: fields_for in fields_for
提问by user3029400
I am learning RoR and i am trying to find how to set a fields_for in another one with has_one models like this:
我正在学习 RoR 并且我正在尝试找到如何使用 has_one 模型在另一个模型中设置 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
I used Nested Model Form Part 1 on Railscasts to get these: In children_controller.rb:
我在 Railscasts 上使用嵌套模型表单第 1 部分来获得这些：在 children_controller.rb 中：
def new
@child = Child.new
[email protected]_father
father.build_grandfather
end
def child_params
params.require(:child).permit(:name, father_attributes:[:name], grandfather_attributes:[:name])
end
And my form:
还有我的表格：
<%= 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 %>
I am trying to retrieve the datas with:
我正在尝试使用以下方法检索数据：
<%= child.father.name %>
<%= child.father.grandfather.name %>
but the grandfather's name won't work. I cannot find the mistake(s)...anyone to help on this? Thanks!
但祖父的名字行不通。我找不到错误（S）...任何人都可以帮助解决这个问题？谢谢！
回答by cschroed
Try switching:
尝试切换：
<%= f.fields_for :grandfather do |fff| %>
to:
到：
<%= ff.fields_for :grandfather do |fff| %>
And switching:
并切换：
params.require(:child).permit(:name, father_attributes:[:name], grandfather_attributes:[:name])
To:
到：
params.require(:child).permit(:name, father_attributes:[:name, grandfather_attributes:[:name]])
