0

我有一个使用seed.rb 从.txt 文件加载的俱乐部和活动列表（即乐队或棒球）。我想在我的视图中创建一个复选框列表，用户可以在其中检查他/她参与的任何活动。我在为活动列表创建迭代时遇到问题，并且收到“nil:NilClass 的未定义方法‘每个’”错误。我的模型称为活动。

我的控制器有 @activities = Activity.all 和

我的观点有 <% @activities.each 做 |a| %>

但是那条线不起作用。Activity 模型有一个名为 :name 的字符串属性，如果有帮助的话。有人有想法我可以试试吗？谢谢！

路线。rb

CollegeConnection::Application.routes.draw do
  devise_for :users

  resources :quizzes
  resources :users
  resources :majors
  resources :activities


  root :to => "users#welcome"
 end

quiz controller:


class QuizzesController < ApplicationController
before_filter :authenticate_user!


# GET /quizzes
# GET /quizzes.json

def index
  @quizzes = Quiz.all

  respond_to do |format|
  format.html # index.html.erb
  format.json { render json: @quizzes }
  end
end

# GET /quizzes/1
# GET /quizzes/1.json
def show
  @quiz = Quiz.find(params[:id])

  respond_to do |format|
  format.html # show.html.erb
  format.json { render json: @quiz }
  end
end

# GET /quizzes/new
# GET /quizzes/new.json
def new
  @quiz = Quiz.new

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

# GET /quizzes/1/edit
def edit
  @quiz = current_user.quizzes.build(params[:id])
end

# POST /quizzes
# POST /quizzes.json
def create
  @quiz = Quiz.new(params[:quiz])
  @quiz.userName=current_user.name
  @activities = Activity.all
  respond_to do |format|
    if @quiz.save
      format.html { redirect_to @quiz, notice: 'Thank You for Taking the Quiz!.' }
      format.json { render json: @quiz, status: :created, location: @quiz }
    else
      format.html { render action: "new" }
      format.json { render json: @quiz.errors, status: :unprocessable_entity }
    end
  end
end

# PUT /quizzes/1
# PUT /quizzes/1.json

def update
  @quiz = Quiz.find(params[:id])

  respond_to do |format|
    if @quiz.update_attributes(params[:quiz])
      format.html { redirect_to @quiz, notice: 'Quiz was successfully updated.' }
      format.json { head :ok }
    else
      format.html { render action: "edit" }
      format.json { render json: @quiz.errors, status: :unprocessable_entity }
    end
  end
end

# DELETE /quizzes/1
# DELETE /quizzes/1.json
def destroy
  @quiz = Quiz.find(params[:id])
  @quiz.destroy

  respond_to do |format|
    format.html { redirect_to quizzes_url }
    format.json { head :ok }
  end
end

结尾

_form.html.erb 测验视图

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

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

<div class="field">
  <%= f.label :q1, "Current/Possible Major" %><br />
  <%= f.collection_select(:q1, Major.all, :name, :name) %>
</div>
<div class="field">
  <%= f.label :q2, "Activities" %><br />
  <%= f.collection_select(:q2, Activity.all, :name, :name) %>
</div>


<% @activities.each do |a| %> 
<%= a.check_box :active %> 
<%= a.submit "Update" %> 
<% end %>


<div class="field">
  <%= f.label :q3 %><br />
  <%= f.text_area :q3, class: 'input-text' %>
</div> 

<div class="actions">
  <%= f.submit "Submit" %>
</div>

好的，所以我找到了一个部分解决方案：

<div class="field">
  <%= f.label :q2, "Activities" %><br />  
  <% for activity in Activity.find(:all) %>
    <div>
      <%= check_box_tag(:q2, activity.name) %> <%=activity.name %>
    </div>
  <% end %>
</div>

它列出了所有旁边带有名称的复选框，但是它没有将值设置为 q2 的答案（问题二的 quiz 属性）我认为我对复选框标签做错了。我试过 f.check_box 但它也不起作用。有什么帮助吗？

错误：

NoMethodError in Quizzes#new

Showing /Users/Daniel/Documents/cis196/CollegeConnection/app/views/quizzes/_form.html.erb
where line #24 is raised

undefined method `merge' for "Debate\n":String
Extracted source (around line #24):

21:     <%= f.label :q2, "Activities" %><br />  
22:     <% for activity in Activity.find(:all) %>
23:     <div>
24:        <%= f.check_box(:q2, activity.name) %> <%=activity.name %>
25:     </div>
26:   <% end %>
27:   </div>
Trace of template inclusion: app/views/quizzes/new.html.erb

Rails.root: /Users/Daniel/Documents/cis196/CollegeConnection 

Application Trace | Framework Trace | Full Trace
app/views/quizzes/_form.html.erb:24:in `block (2 levels) in      _app_views_quizzes__form_html_erb__435461842904466959_70320063188680'

app/views/quizzes/_form.html.erb:22:in each' app/views/quizzes/_form.html.erb:22:inblock in _app_views_quizzes__form_html_erb__435461842904466959_70320063188680' app/views/quizzes/_form.html.erb:1:in _app_views_quizzes__form_html_erb__435461842904466959_70320063188680' app/views/quizzes/new.html.erb:6:in_app_views_quizzes_new_html_erb__735256988922435877_70320063679640' app/controllers/quizzes_controller.rb:31:in `new'要求

参数：

无 显示会话转储

显示环境转储

回复

标题：

没有任何

测验模型

Class Quiz < ActiveRecord::Base
belongs_to :user

validates :q1, :presence => true
validates :q2, :presence => true
validates :q3, :presence => true

serialize :q2

结尾

4

1 回答 1

1

这就是我认为正在发生的事情。您的 _form 部分是部分的，因为它可能由您的创建视图和编辑视图共享。_form 部分依赖于被初始化的@activities。您仅在创建操作中对其进行了初始化。尝试这样的事情：

quizzes_controller.rb

QuizzesController < ApplicationController
  before_filter load, :only =>[:create, :edit]
  def load
    @activities = Activity.all
  end
end

然后你可以删除

@activities = Activity.all

从您的创建操作中，@activities 将在您的创建和编辑操作中初始化。

更新：

check_box_tag 接受 3 个（或更多）参数，第一个是元素的 id，第二个是要传递的值，第三个是一个布尔值，如果为 true，则会检查复选框。

所以现在你必须发布你的模型和关联做 Quiz 'has_many' 活动等。

于 2012-05-01T22:05:21.200 回答