茧 nested_form 渲染自己

Question

我正在尝试创建一个用 cocoon 调用自身的表单，问题 has_many 个问题，正在生成无限循环:(

型号

class Question < ActiveRecord::Base
  has_many :questions,:foreign_key => "parent_id", :dependent =>:destroy
  belongs_to :basic_component

  attr_accessible :description, :questions_attributes, :questions

end

我的问题_form

<%= semantic_form_for [:admin, @question] do |f| %>
  <%= f.inputs do %>
    <%= f.input :description %>
    <div class="questions">
      <%= f.semantic_fields_for :questions do |question| %>
          <%= render 'question_fields', :f => question %>
      <% end %>
      <div class="links">
        <%= link_to_add_association("Nova Pergunta", f, :questions, class: 'button') %>
      </div>
    </div>
  <% end %>
  <%= f.actions %>
<% end %>

我的_question_fields

<div class="nested-fields">
  <%= f.inputs do %>
    <%= f.input :description} %>
    <div class="questions">
      <%= f.semantic_fields_for :questions do |question| %>
        <%= render 'question_fields', :f => question %>
      <% end %>
      <div class="links">
        <%= link_to_add_association("Nova Pergunta", f, :questions, class: 'button') %>
      </div>
    </div>
  <% end %>
</div>

无限循环:(,如何解决？

  Rendered admin/questions/_question_fields.html.erb (168.4ms)
  Rendered admin/questions/_question_fields.html.erb (376.2ms)
  Rendered admin/questions/_question_fields.html.erb (586.4ms)
  Rendered admin/questions/_question_fields.html.erb (780.2ms)

Answer 1

在您的问题字段中，您有：

<%= f.semantic_fields_for :questions do |question| %>
  <%= render 'question_fields', :f => question %>
<% end %>

这是导致循环的原因。因为你在文件中，所以你一遍又一遍地调用这个文件。

Answer 2

link_to_add_association 也会在服务器端预渲染嵌套表单，所以当 link 被点击时，它可以插入 "new" 项。

这就是你的无限循环的来源：link_to_add_association 呈现嵌套形式，它也呈现嵌套形式，link_to_add_association 也呈现......无限;）

如果您真的希望能够构建一棵 indefinite/unlimited 树，cocoon 不适合您。您将不得不求助于 ajax.

但是，如果您可以限制最大深度，则可以很容易地向视图添加一个额外参数，如果级别低于您的最大级别，该参数只会呈现 link_to_add_association。

这在 cocoon 问题之前已经出现过，可能的解决方案是 demonstrated

简而言之，假设最大深度为 5，您可以执行以下操作（为了便于阅读）：

= semantic_form_for [:admin, @question] do |f| 
  = f.inputs do
    = f.input :description
      .questions
        = f.semantic_fields_for :questions do |question|
          = render 'question_fields', f: question, depth: 0
      .links
        = link_to_add_association "Nova Pergunta", f, :questions, 
             class: 'button', render_options: {locals: {depth: 0}}
  = f.actions

和你的 question_fields 部分然后测试这个 depth （并传播它）

.nested-fields
  = f.inputs do
    = f.input :description
    .questions
      = f.semantic_fields_for :questions do |question| 
        = render 'question_fields', :f => question, depth: depth + 1
    - if depth < 5
      .links
        = link_to_add_association "Nova Pergunta", f, :questions, 
          class: 'button', render_options: {locals: {depth: depth + 1}}

茧 nested_form 渲染自己

Cocoon nested_form render yourself

ruby-on-rails

has-many

apache-cocoon