link_to_remove_association: 未定义方法“new_record?” nil:NilClass

Question

我正在尝试使用 Cocoon 构建 2 个嵌套表单，效果很好。我有一个有很多问题的游戏模型，一个问题有很多答案。

型号

# Game model
class Game < ApplicationRecord
  has_many :questions, dependent: :destroy
  accepts_nested_attributes_for :questions, allow_destroy: true
end

# Question model
class Question < ApplicationRecord
  belongs_to :game
  has_many :answers, dependent: :destroy
  validates :text, presence: true
  accepts_nested_attributes_for :answers, allow_destroy: true
end


# Answer model
class Answer < ApplicationRecord
  belongs_to :question
end

link_to_add_association link 无处不在，link_to_remove 关联 link 在 _question_fields 部分视图中工作正常，但我有

`"undefined method `new_record?' for nil:NilClass"` 

当我在 _answer_fields 部分视图中插入 link_to_remove_association 时出错。我确定这是我的错误，但我无法检索到哪里。

错误

观看次数

new.html.erb

<%= form_with(model: @game,  url: games_path, local: true ) do |form| %>

  <div class="form-group game">
    <%= form.label(':name', "Title") %>
    <%= form.text_field ':name', class: 'form-control form-control-sm' %>
  </div>

  <div class="wrapper-questions"></div>

  <%= form.fields_for :questions do |question_form| %>
    <%= render 'games/partials/question_fields', f: question_form %>
  <% end %>

  <div class="row form-actions links">
    <div class="col-sm">
      <%= link_to_add_association 'Add a question',
          form,
          :questions,
          :partial => 'games/partials/question_fields',
          class: "btn btn-secondary",
          'data-association-insertion-node' => '.wrapper-questions'
      %>
    </div>

    <div class="col-sm text-right">
      <%= form.submit 'Save', :class => "btn btn-primary" %>
    </div>
  </div>
<% end %>

partials/_question_fields.html.erb

<div class="question-wrapper jumbotron nested-fields">
  <%= link_to_remove_association f, { class: 'btn btn-light' } do %>
    <i class="fa fa-trash" aria-hidden="true"></i> Delete the question
  <% end %>

  <p><strong>Question</strong></p>

  <div class="form-group">
    <strong><%= f.label(:text, 'Question:') %></strong>
    <%= f.text_field :text, class: "form-control" %>
  </div>

  <%= f.fields_for :questions do |answer_form| %>
    <%= render 'games/partials/answer_fields', f: answer_form %>
  <% end %>

  <div class="row">
    <div id="wrapper-answers"></div>
    <div class="col-sm">
      <%= link_to_add_association 'Add an answer',
          f,
          :answers,
          :partial => 'games/partials/answer_fields',
          data: { 'association-insertion-method' => :prepend },
          class: "btn btn-secondary"
      %>

    </div>
  </div>
</div>

partials/_answer_fields.html.erb

<div class="row nested-fields">
  <div class="col">
    <%= f.text_field :text, class: "form-control" %>
  </div>

  <div class="col">
    <label class="btn btn-secondary form-control">
      <%= f.check_box :correct %>
    </label>
  </div>


  <!-- My error is here -->
  <%= link_to_remove_association 'remove answer', f %>
</div>

有人知道我做错了什么吗？ 问候， 莉莉丝

Answer 1

在partials/_question_fields.html.erb

<%= f.fields_for :questions do |answer_form| %>

应该是：

<%= f.fields_for :answers do |answer_form| %>