ruby-on-rails - 嵌套形式的批量赋值

Question

我正在关注 railscasts 196 剧集，我尝试了他所拥有的，但我遇到了以下错误

ActiveModel::MassAssignmentSecurity::Error in SurveysController#create
Can't mass-assign protected attributes: questions_attributes
Rails.root: /home/jean/rail/surveysays

这里是我的代码

调查表

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

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

  <div class="field">
    <%= f.label :name %><br />
    <%= f.text_field :name %>
  </div>

  <%= f.fields_for :questions do |bf|%>
    <%= bf.label :content, "Question" %><br />
    <%= bf.text_area :content, :rows=> 3 %>
  <% end %>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

调查关系

class Survey < ActiveRecord::Base
  has_many :questions, :dependent => :destroy
  accepts_nested_attributes_for :questions
  attr_accessible :name
end

问题关系

class Question < ActiveRecord::Base
  belongs_to :survey
  attr_accessible :content, :survey_id
end

新 Controller

def new
    @survey = Survey.new
    3.times {@survey.questions.build }

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @survey }
    end
  end

Answer 1

把你的类(class)改成这个

class Survey < ActiveRecord::Base
  has_many :questions, :dependent => :destroy
  accepts_nested_attributes_for :questions
  attr_accessible :name, :questions_attributes
end

查找主题“使用 attr_accessible”here了解更多信息