Ruby On Rails in UA/Разработка на ROR/Несколько вопросов

class Question < ActiveRecord::Base
  has_many :answers
end

class Answer < ActiveRecord::Base
  belongs_to :question
end

class SurveysController < ApplicationController
  def index
    @surveys = Survey.all
  end
  
  def show
    @survey = Survey.find(params[:id])
  end
  
  def new
    @survey = Survey.new
    3.times do
      question = @survey.questions.build
      4.times { question.answers.build }
    end
  end
  
  def create
    @survey = Survey.new(params[:survey])
    if @survey.save
      flash[:notice] = "Successfully created survey."
      redirect_to @survey
    else
      render :action => 'new'
    end
  end
  
  def edit
    @survey = Survey.find(params[:id])
  end
  
  def update
    @survey = Survey.find(params[:id])
    if @survey.update_attributes(params[:survey])
      flash[:notice] = "Successfully updated survey."
      redirect_to @survey
    else
      render :action => 'edit'
    end
  end
  
  def destroy
    @survey = Survey.find(params[:id])
    @survey.destroy
    flash[:notice] = "Successfully destroyed survey."
    redirect_to surveys_url
  end
end

class Answer < ActiveRecord::Base
  belongs_to :question
end

class Question < ActiveRecord::Base
  belongs_to :survey
  has_many :answers, :dependent => :destroy
  accepts_nested_attributes_for :answers, :reject_if => lambda { |a| a[:content].blank? }, :allow_destroy => true
end

class Survey < ActiveRecord::Base
  has_many :questions, :dependent => :destroy
  accepts_nested_attributes_for :questions, :reject_if => lambda { |a| a[:content].blank? }, :allow_destroy => true
end

<p class="fields">
  <%= f.label :content, "Answer" %>
  <%= f.text_field :content %>
  <%= link_to_remove_fields "remove", f %>
</p>

<% form_for @survey do |f| %>
  <%= f.error_messages %>
  <p>
    <%= f.label :name %><br />
    <%= f.text_field :name %>
  </p>
  <% f.fields_for :questions do |builder| %>
    <%= render "question_fields", :f => builder %>
  <% end %>
  <p><%= link_to_add_fields "Add Question", f, :questions %></p>
  <p><%= f.submit "Submit" %></p>
<% end %>

<div class="fields">
  <p>
    <%= f.label :content, "Question" %>
    <%= link_to_remove_fields "remove", f %><br />
    <%= f.text_area :content, :rows => 3 %>
  </p>
  <% f.fields_for :answers do |builder| %>
    <%= render 'answer_fields', :f => builder %>
  <% end %>
  <p><%= link_to_add_fields "Add Answer", f, :answers %></p>
</div>

<% title "Edit Survey" %>

<%= render :partial => 'form' %>

<p>
  <%= link_to "Show", @survey %> |
  <%= link_to "View All", surveys_path %>
</p>

<% title "Surveys" %>

<table>
  <tr>
    <th>Name</th>
  </tr>
  <% for survey in @surveys %>
    <tr>
      <td><%=h survey.name %></td>
      <td><%= link_to "Show", survey %></td>
      <td><%= link_to "Edit", edit_survey_path(survey) %></td>
      <td><%= link_to "Destroy", survey, :confirm => 'Are you sure?', :method => :delete %></td>
    </tr>
  <% end %>
</table>

<p><%= link_to "New Survey", new_survey_path %></p>

<% title "New Survey" %>

<%= render :partial => 'form' %>

<p><%= link_to "Back to List", surveys_path %></p>

<% title "Survey" %>

<p>
  <strong>Name:</strong>
  <%=h @survey.name %>
</p>

<ol>
<% for question in @survey.questions %>
  <li>
    <%=h question.content %>
    <ul>
    <% for answer in question.answers %>
      <li><%=h answer.content %></li>
    <% end %>
    </ul>
  </li>
<% end %>
</ol>

<p>
  <%= link_to "Edit", edit_survey_path(@survey) %> |
  <%= link_to "Destroy", @survey, :confirm => 'Are you sure?', :method => :delete %> |
  <%= link_to "View All", surveys_path %>
</p>

function remove_fields(link) {
  $(link).previous("input[type=hidden]").value = "1";
  $(link).up(".fields").hide();
}

function add_fields(link, association, content) {
  var new_id = new Date().getTime();
  var regexp = new RegExp("new_" + association, "g")
  $(link).up().insert({
    before: content.replace(regexp, new_id)
  });
}

function remove_fields(link) {
  $(link).prev("input[type=hidden]").val("1");
  $(link).closest(".fields").hide();
}

function add_fields(link, association, content) {
  var new_id = new Date().getTime();
  var regexp = new RegExp("new_" + association, "g")
  $(link).before(content.replace(regexp, new_id))
}

<% form_for @survey do |f| %>
  <%= f.error_messages %>
  <p>
    <%= f.label :name %><br />
    <%= f.text_field :name %>
  </p>
  <% f.fields_for :questions do |builder| %>
    <%= render "question_fields", :f => builder %>
  <% end %>
  <p><%= link_to_add_fields "Add Question", f, :questions %></p>
  <p><%= f.submit "Submit" %></p>
<% end %>

<div class="fields">
  <p>
    <%= f.label :content, "Question" %>
    <%= link_to_remove_fields "remove", f %><br />
    <%= f.text_area :content, :rows => 3 %>
  </p>
  <% f.fields_for :answers do |builder| %>
    <%= render 'answer_fields', :f => builder %>
  <% end %>
  <p><%= link_to_add_fields "Add Answer", f, :answers %></p>
</div>

# Methods added to this helper will be available to all templates in the application.
module ApplicationHelper
  def link_to_remove_fields(name, f)
    f.hidden_field(:_destroy) + link_to_function(name, "remove_fields(this)")
  end
  
  def link_to_add_fields(name, f, association)
    new_object = f.object.class.reflect_on_association(association).klass.new
    fields = f.fields_for(association, new_object, :child_index => "new_#{association}") do |builder|
      render(association.to_s.singularize + "_fields", :f => builder)
    end
    link_to_function(name, h("add_fields(this, '#{association}', '#{escape_javascript(fields)}')"))
  end
end

link_to_function(name, "add_fields(this, '#{association}', '#{escape_javascript(fields)}'"))

link_to_function(name, "add_fields(this, '#{association}', '#{escape_javascript(fields)}'".html_safe))