Question

在我的views/practice_questionx/index.html.erb文件中，我想在每次页面加载时从数据库中混洗模型的某些属性。我知道我必须将属性放入数组并在它们上调用.shuffle方法，但我真的很难理解语法以及如何做到这一点。

视图/ practice_questions / index.html.erb

<% @practice_questions.each do |practice_question| %>

 ...

<p class="main-practice-question-answer">
  <%= practice_question.answer_choice_one %> 
</p>

<p class="main-practice-question-answer">
  <%= practice_question.answer_choice_two %> 
</p>

<p class="main-practice-question-answer">
  <%= practice_question.answer_choice_three %> 
</p>

<p class="main-practice-question-answer">
  <%= practice_question.answer_choice_four %> 
</p>

<p class="main-practice-question-answer">
  <%= practice_question.answer_choice_five %> 
</p>

控制器/ practice_questions_contoller.rb

class PracticeQuestionsController < ApplicationController
  before_action :authenticate_user!
  before_action :set_practice_quiz, only: [:show, :edit, :update, :destroy]
  before_action :set_practice_question, only: [:show, :edit, :update, :destroy]

    @practice_questions = PracticeQuiz.all.friendly.find(params[:practice_quiz_id]).practice_questions.order('created_at ASC').paginate(:page => params[:page], per_page: 1)
    # first get the practicequiz with its friendly id, passing it its real id, then get all the pracice questions, then paginate it?


  def show
  @question = PracticeQuestion.find_by(id: params[:id])
  end

private
def set_practice_question
  @practice_question = PracticeQuestion.find(params[:id])
end

def set_practice_quiz
  @practice_quiz = PracticeQuiz.friendly.find(params[:practice_quiz_id])
end

# Never trust parameters from the scary internet, only allow the white list through.
def practice_question_params
  params.require(:practice_question).permit(:question, :explanation, :flagged, :answer_choice_one, :answer_choice_two, :answer_choice_three, :answer_choice_four, :answer_choice_five, :answer_choice_correct)
end

end

模式

 create_table "practice_questions", force: :cascade do |t|
    t.text "question"
    t.text "explanation"
    t.boolean "flagged"
    t.string "user_id"
    t.bigint "practice_quiz_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.text "answer_choice_one"
    t.text "answer_choice_two"
    t.text "answer_choice_three"
    t.text "answer_choice_four"
    t.text "answer_choice_five"
    t.text "answer_choice_correct"
    t.index ["practice_quiz_id"], name: "index_practice_questions_on_practice_quiz_id"
  end

最终，我想在每个页面加载时只调整五个答案选项，因此它们每次都以随机顺序显示。我一直想弄清楚几个小时，似乎无法理解如何去做。

Answer 1

不是最好的解决方案，但可能会节省您的一天。

在你的模特中，

def answers
  [
    answer_choice_one, answer_choice_two, 
    answer_choice_three, answer_choice_four, 
    answer_choice_five
  ].shuffle
end

在你看来，

<% practice_question.answers.each do |answer| %>
  <p class="main-practice-question-answer">
    <%= answer %> 
  </p>
<% end %>

Answer 2

使用您当前的数据库模式，最简单的方法是将您的答案加载到自己的数组中，对该数组进行洗牌，然后遍历它：

jquery

以下是代码的作用：

首先，它构建了一个＆＃34;一个＆＃34;，＆＃34;两个＆＃34;，＆＃34;三个＆＃34;，＆＃34;四个＆＃34;，＆＃34 ;五＆＃34;使用Ruby的percent string语法
然后在该阵列上调用#map，转换＆＃34;一个＆＃34;，＆＃34;两个＆＃34;，＆＃34;三个＆＃34;等到给定数字的答案选择。它通过在<% answer_choices = %w(one two three four five).map { |number| practice_question.public_send("answer_choice_#{number}") }.shuffle answer_choices.each do |choice| %> <p class="main-practice-question-answer"> <%= choice %> </p> <% end %>对象上调用#public_send来实现此目的，这是调用构建
然后在结果上调用practice_question，随机输入我们的问题
然后我们可以遍历我们的随机答案选择数组，随时打印出每个选项。万岁！

Rails 5在页面加载时洗牌资源属性

2 个答案: