无法更新 Rails 4.2.6 中的嵌套属性

Question

我将 Rails 从 3.2 迁移到 Rails 4.2.6。我有 2 个表，其中 报告：has_many => 图标。我为报告和图标属性添加了强大的参数。创建功能工作正常，在更新功能时，我可以更新报告但无法更新图标，而是每次点击更新操作时都会创建新图标。 这是我的代码：

report.rb:

class Report < ActiveRecord::Base
  has_many :icons, -> { order 'position_id ASC'}
  accepts_nested_attributes_for :icons, :reject_if => lambda { |a| a[:icon].blank? }, :allow_destroy => true
end

icon.rb:

class Icon < ActiveRecord::Base
  belongs_to :report
end

报告控制器：

  def update
    respond_to do |format|
      if @report.update_attributes(report_params)
        @report.save
        format.html { redirect_to(user_reports_url, :notice => 'Report was successfully updated.') }
        format.json { render :json => { :success => true, :report_id => @report.id, :report_title => @report.title, :icon_array => @report.icons, :redirect => report_url(@report.id) } }
        format.xml  { head :ok }
      else
        format.html { render :action => "edit" }
        format.xml  { render :xml => @report.errors, :status => :unprocessable_entity }
      end
    end
  end

  private

  def report_params
    params.require(:report).permit(:title, :comments, :remarks,{:icons_attributes => [:id, :icon, :rotation, :top, :_destroy]})
  end

我通过将 puts 放入控制器中看到了日志，图标在 @report.update_attributes(report_params) 步骤插入，这是日志：

由 ReportsController#update 处理为 JSON 参数： {"utf8"=>"✓", "report"=>{"title"=>"title1", "cmets"=>"这是一条评论", "icons_attributes"=>{"0"=>{"id"=>"", "icon"=>"market_indicator", "rotation"=>"0", "top"=>"", "_destroy"=>"false"}, "id"=>"87"}

报告负载 (0.3ms) SELECT "reports".* FROM "reports" WHERE "reports"."deleted_at" IS NULL AND "reports"."id" = ?限制 1 [["id", 87]]
SQL (1.6ms) INSERT INTO "icons" ("icon", "rotation", "top") 值 (?, ?, ?) [["icon", "market"], ["rotation", "0"], ["top", ""], ["left", ""]] (12.0ms) 提交事务
ActiveRecord::Associations::CollectionProxy

我把日志写成：

  def update
    puts @report.icons.inspect
    respond_to do |format|
     .....
  end

结果如下：

图标加载 (0.9ms) SELECT "icons".* FROM "icons" WHERE "icons"."report_id" = ? ORDER BY position_id ASC [["report_id", 91]]

<ActiveRecord::Associations::CollectionProxy [#<Icon id: 204, report_id: 91, icon: "asking_price", rotation: "", top: "150", left: "165">]>

Answer 1

您的 "icon_attributes" 没有传递图标的 ID。

"icons_attributes"=>{"0"=>{"id"=>"", "icon"=>"market_indicator", "rotation"=>"0", "top"=>"", "_destroy"=>"false"}, "id"=>"87"}

您会注意到 id 是空白的。由于 id 是空白 rails 认为这是一条新记录，因此创建了一个新图标。错误在于您是如何制作表单的。