Rails集合仅选择保存部分属性

Question

我正在尝试理解如何做一件简单的事情--从collection_select中保存id和文本。我刚刚开始使用RoR，所以我还没有很好地掌握所有的东西。我的经验主要是Java外加一些Perl，所以我可能没有选择正确的方法。

我有一个缺陷，它有一个DefectRootCause。还有另一个实体，DefaultRootCauses，我可以从中选择与缺陷相关联的DefectRootCause.root_cause。我正在尝试用它的DefectRootCause来保存这个缺陷。DefectRootCause应该将root_cause字段作为文本，即从DefaultRootCause中选择的值。问题是我只能为DefectRootCause保存一个root_cause或default_root_cause_id。此外，DefectRootCause.root_cause从DefaultRootCause而不是文本中获取id。

请告诉我，如果我试图让所有事情都“神奇地”发生，或者我是否应该在控制器中对数据进行一些处理，请让我知道这是正确的。代码见下文。

我有模型：

class Defect < ActiveRecord::Base

  has_one :defect_root_cause, :dependent => :destroy
  has_many :default_root_cause, :through => :defect_root_cause

end

class DefectRootCause < ActiveRecord::Base
  belongs_to :defect
  belongs_to :default_root_cause

end

class DefaultRootCause < ActiveRecord::Base

  has_many :defect_root_causes
  has_many :defects, :through => :defect_root_causes
end

控制器(我想我只需要修改其中的一个)：

  # POST /defects
  # POST /defects.json
  def create
    #I am doing this because the attributes are not named :defect_root_cause_attribues, I don't know yet why
    @defect = Defect.new(defect_params.except(:defect_root_cause))
    @defect.defect_root_cause = DefectRootCause.new(defect_params[:defect_root_cause])
    respond_to do |format|
      if @defect.save
        format.html { redirect_to @defect, notice: 'Defect was successfully created.' }
        format.json { render :show, status: :created, location: @defect }
      else
        format.html { render :new }
        format.json { render json: @defect.errors, status: :unprocessable_entity }
      end
    end
end
  # PATCH/PUT /defects/1
  # PATCH/PUT /defects/1.json
  def update
        respond_to do |format|
        #I am doing this because the attributes are not named :defect_root_cause_attribues, I don't know yet why
      if @defect.update(defect_params.except(:defect_root_cause)) && @defect.defect_root_cause.update(defect_params[:defect_root_cause])
        format.html { redirect_to @defect, notice: 'Defect was successfully updated.' }
        format.json { render :show, status: :ok, location: @defect }
      else
        format.html { render :edit }
        format.json { render json: @defect.errors, status: :unprocessable_entity }
      end
  end
end

# Never trust parameters from the scary internet, only allow the white list through.
    def defect_params
        #I am doing this because the attributes are not named :defect_root_cause_attribues, I don't know yet why
      params.require(:defect).permit(:details, defect_root_cause: [:id, :details, :root_cause, :default_root_cause_id])
    end

现在视图：

<%= form_for @defect do |f| %>
  <% if @defect.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@defect.errors.count, "error") %> prohibited this defect from being saved:</h2>

      <ul>
      <% @defect.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :details %><br>
    <%= f.text_field :details %>
    <%= f.fields_for @defect.defect_root_cause do |drc| %>
    <%= drc.label :root_cause%>
    <%= drc.collection_select(:default_root_cause_id, DefaultRootCause.all, :id, :root_cause, :prompt => true) %>

    <%= drc.label :details%>
    <%= drc.text_field :details %>
  <% end %>
  </div>
      <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

在routes.rb中，我只有以下内容：

  resources :default_root_causes
  resources :defects
  resources :defect_root_causes

  # You can have the root of your site routed with "root"
  root 'defects#index'

最后，我的问题(root_cause为空)：

irb(main):006:0> DefectRootCause.find(10)
  DefectRootCause Load (0.3ms)  SELECT  `defect_root_causes`.* FROM `defect_root_causes` WHERE `defect_root_causes`.`id` = 10 LIMIT 1
=> #<DefectRootCause id: 10, details: "sadsad", defect_id: 9, default_root_cause_id: 2, created_at: "2016-02-19 05:52:06", updated_at: "2016-02-19 05:52:06", root_cause: nil>

如果我将选择更改为：

<%= drc.collection_select(:root_cause, DefaultRootCause.all, :id, :root_cause, :prompt => true) %>

我得到如下信息(root_cause被保存，但它是一个数字，而不是文本-在本例中，我想要以下文本："second root cause"，加上default_root_cause_id为空)：

irb(main):005:0> DefectRootCause.find(9)
  DefectRootCause Load (0.3ms)  SELECT  `defect_root_causes`.* FROM `defect_root_causes` WHERE `defect_root_causes`.`id` = 9 LIMIT 1
=> #<DefectRootCause id: 9, details: "das", defect_id: 8, default_root_cause_id: nil, created_at: "2016-02-19 05:42:36", updated_at: "2016-02-19 05:42:36", root_cause: "2">

编辑：

现在，我将我所做的将所有信息保存在我需要的地方。我现在将其作为答案发布，因为我仍然不知道这是不是正确的方法。所以，如果你知道应该以不同的方式来做，请让我知道。我特别关注如何从视图中发送所有信息。我看到视图“知道”所选DefaultRootCause的id和文本，但我没有在发送的params中同时获得这两个内容。

那么，现在是代码。

查看：

<%= drc.select :default_root_cause_id, DefaultRootCause.all.collect{|r| [r.root_cause, r.id]}, :prompt => true %>

defects_controller.rb
def create
@defect = Defect.new(defect_params.except(:defect_root_cause))
@defect.defect_root_cause = DefectRootCause.create(defect_params[:defect_root_cause].merge(:root_cause => DefaultRootCause.find(defect_params[:defect_root_cause][:default_root_cause_id]).root_cause))
respond_to do |format|........
def update
respond_to do |format|
  if @defect.update(defect_params.except(:defect_root_cause)) && @defect.defect_root_cause.update(defect_params[:defect_root_cause].merge(:root_cause => DefaultRootCause.find(defect_params[:defect_root_cause][:default_root_cause_id])))

有了这些，我得到了以下参数和以下插入：

 Parameters: {"utf8"=>"✓", "authenticity_token"=>"jGUQIxeXWZwg5lqsPFrE4vO9z4ioRnAN/Z1/K9scQiIeQ0MTHBTvZoDcwHKtGvrgrG53y4yr7tX4wnCShoZ/oA==", "defect"=>{"details"=>"a", "defect_root_cause"=>{"default_root_cause_id"=>"2", "details"=>"a"}}, "commit"=>"Create Defect"}
  DefaultRootCause Load (0.1ms)  SELECT  `default_root_causes`.* FROM `default_root_causes` WHERE `default_root_causes`.`id` = 2 LIMIT 1
  CACHE (0.0ms)  SELECT  `default_root_causes`.* FROM `default_root_causes` WHERE `default_root_causes`.`id` = 2 LIMIT 1  [["id", "2"]]
  CACHE (0.0ms)  SELECT  `default_root_causes`.* FROM `default_root_causes` WHERE `default_root_causes`.`id` = 2 LIMIT 1  [["id", "2"]]
   (0.1ms)  BEGIN
   SQL (0.2ms)  INSERT INTO `defect_root_causes` (`details`, `default_root_cause_id`, **`root_cause`**, `created_at`, `updated_at`) VALUES ('a', 2, **'second root cause'**, '2016-02-23 07:10:59', '2016-02-23 07:10:59')

现在，请让我知道这是不是“正确”的方法。

谢谢你，维克多

Answer 1

您正在尝试通过父级更新关联的属性，这意味着您需要使用accepts_nested_attributes_for。将此方法添加到Defect模型中，如下所示：

类缺陷< ActiveRecord::Base

has_one :defect_root_cause，:dependent => :destroy has_many :default_root_cause，:through => :defect_root_cause

accepts_nested_attributes_for :defect_root_cause结束

完成此操作后，转到defects_controller.rb并将#defect_params方法更新为：

params.require(:defect).permit(:details, defect_root_cause_attributes: [:id, :details, :root_cause, :default_root_cause_id])

Answer 2

您可以使用以下代码：

<%=f.select :default_root_cause_id,  DefaultRootCause.all.collect{|r| [r.route_cause,"#{r.route_cause} - #{r.id}"]} %>