在 rails 3.2.* 我有一个 has_one belongs_to 嵌套模型,如下所示:
class Unicycle < ActiveRecord::Base
attr_accessible :brand, :wheel, :wheel_attributes
has_one :wheel
accepts_nested_attributes_for :wheel
end
class Wheel < ActiveRecord::Base
attr_accessible :diameter, :unicycle
belongs_to :unicycle
end
我的控制器看起来像这样:
class UnicyclesController < ApplicationController
def index
@unicycles = Unicycle.all
end
def edit
@unicycle = Unicycle.find_by_id params[:id]
end
def update
@unicycle = Unicycle.find_by_id params[:id]
if @unicycle.update_attributes! params[:unicycle]
redirect_to unicycles_path
else
render 'edit'
end
end
end
我的 edit.html.erb 像这样:
<%= form_for @unicycle do |formbuilder| %>
<%= formbuilder.text_field :brand %>
<%= fields_for @unicycle.wheel do |fieldbuilder| %>
<%= fieldbuilder.number_field :diameter %>
<% end %>
<%= formbuilder.submit %>
<% end %>
但是当我更新时,对 wheel.diameter 所做的更改会被默默地忽略。
我发现即使我的fields_for
调用嵌套form_for
在 edit.html.erb 的块中,发送到我的更新函数的参数也不是嵌套的。
参数包含:
{"utf8"=>"✓",
"_method"=>"put",
"authenticity_token"=>"owiV5xwbbt+ft8h4K4bIqshp5I6jrlj5XWEKeVXpoCQ=",
"unicycle"=>{"brand"=>"Unibike"},
"wheel"=>{"diameter"=>"70"},
"commit"=>"Update Unicycle",
"action"=>"update",
"controller"=>"unicycles",
"id"=>"1"}
但根据 rails 文档(ActiveRecordNestedAttributes),车轮参数应该真正嵌套在 unicycle 中,如下所示:
"unicycle"=>{"brand"=>"Unibike", "wheel"=>{"diameter"=>"68"}},
我在这里想念什么?