Question

我有从数据库中获取的对象集合，当我使用.each方法对其进行迭代时，我得到的单个对象只有空值，如下所示：

      - !ruby/object:List
        attributes:
          id: 4
          title: Test
          project_id: 10
          created_at: 2013-12-29 20:53:04.087839000 Z
          updated_at: 2013-12-29 20:53:04.087839000 Z
      - !ruby/object:List
        attributes:
          id: 5
          title: Testng
          project_id: 10
          created_at: 2013-12-29 20:53:59.087687000 Z
          updated_at: 2013-12-29 20:53:59.087687000 Z
      - !ruby/object:List
        attributes:
          id: 
          title: 
          project_id: 10
          created_at: 
          updated_at:

什么是好的，但是...在我的SQLite3数据库中我只有两行......因为在这里工作对我来说没有任何问题我想了解它为什么会发生。你能解释一下吗？

这是我的控制器和局部视图，其中我正在使用@current_lists变量

projects_controller.rb

  def show
    @project = Project.find(params[:id])

    @attachment = Attachment.new
    @list = @project.lists.new

    @current_lists = @project.lists
    @current_attachments = @project.attachments
    @current_issues = @project.issues.includes(:category)

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @project }
    end
  end

_lists.html.haml

- @current_lists.each do |project|
    .col-md-4
      .panel.panel-default
        .panel-heading
          =project.title
          .pull-right.text-success
            %a.fa.fa-plus.fa-lg
        %ul.list-group.task-list
          %li.list-group-item.selected
            %label.label-checkbox.inline
              %input.task-finish{checked: "checked", type: "checkbox"}/
              %span.custom-checkbox
            SEO Optimisation
            %span.pull-right
              %a.task-del{href: "#"}
                %i.fa.fa-trash-o.fa-lg.text-danger
        / /list-group

编辑：这是我用来渲染使用@list实例变量的表单的模态代码：

/ /Modal
#newList.modal.fade
  .modal-dialog
    .modal-content
      .modal-header
        %button.close{"aria-hidden" => "true", "data-dismiss" => "modal", type: "button"} &times;
        %h4 Modal with form
      .modal-body
        =form_for [@project, @list] do |f|
          - if @list.errors.any?
            #error_explanation
              %h2= "#{pluralize(@list.errors.count, "error")} prohibited this list from being saved:"
              %ul
                - @list.errors.full_messages.each do |msg|
                  %li= msg

          .form-group
            = f.label :title
            = f.text_field :title, class: 'form-control input-sm'
          .form-group
            = f.submit 'Save', class: '.btn.btn-success'
    / /.modal-content
  / /.modal-dialog
/ /.modal

提前谢谢！

Answer 1

您正在使用代码

在项目控制器中创建一个空列表对象

@list = @project.lists.new

解决方案是仅从@project.lists选择已保存的对象：

@current_lists = @project.lists.to_a.select { |list| !list.new_record? }

这将从@current_lists数组中删除未保存的记录。

已修改为包含解决方案

集合中具有空属性的对象

1 个答案: