Rails 4，通過傳入參數在控制器中構建/創建多個表條目

Question

我是Rails的新手，正在嘗試通過Test和TestQuestions模型在一個表中創建多個條目，但沒有成功。 最終，我想根據其類別選擇50個問題。 我被困在這一步，試圖傳遞category_id參數以從TestController / Test Model更新我的test_questions表。

下面控制器中的注釋行：“ @ test.test_questions.build（：question_id => 5）.save”使一個問題編號為5，但是當我致電@ test.build_category_test！（category_params）.save時，調用一個方法並傳遞一個數組，我得到錯誤的未定義方法“ build_category_test！”。 適用於#Test：0x000000047f0928

楷模

class TestQuestions < ActiveRecord::Base
  belongs_to :test 
end

class Test < ActiveRecord::Base
  has_many :test_questions, class_name: "TestQuestions",
                            foreign_key: "test_id"

  def self.build_category_test!(category_ids)
    unless category_ids.blank?
      category_ids.each do |u|
        test_questions.build!(:question_id => 5)        
      end
    end
  end
end

調節器

class TestsController < ApplicationController
  def create
  @test = Test.new(test_params)

  respond_to do |format|
    if @test.save
      #@test.test_questions.build(:question_id => 5).save
      @test.build_category_test!(category_params).save
      format.html { redirect_to @test, notice: 'Test was successfully created.' }
      format.json { render action: 'show', status: :created, location: @test }
    else
      format.html { render action: 'new' }
      format.json { render json: @test.errors, status: :unprocessable_entity }
    end
  end

  def category_params
    params[:category][:category_ids]
  end

end

test / new.html.erb的視圖

<%= form_tag tests_path, :method => :post do %>
<%= hidden_field_tag "user_id", @user_id %>
<ul>
<% for c in @categories %>
  <li>
  <%= check_box_tag "category[category_ids][]", c.id %>
  <%= c.category %>
  </li>
<% end %>
</ul>
<%= submit_tag "Create Test" %>

參數的日志：“ user_id” =>“ 1”，“ category” => {“ category_ids” => [“ 1”，“ 2”]}，“ commit” =>“ Create Test”}

Answer 1

方法build_category_test! 應該是一個實例方法：

def build_category_test!(category_ids) # @test.build_category_test!

代替類方法：

def self.build_category_test!(category_ids) # Test.build_category_test!