動態一對多表單建立.html.erb

1. MODEL
 item has many item_childrens
->  user has one answersheet
 
2. CONTROLLER 
item_controller -> user_controller
multi method   -> useranswer method

3. CONTROLLER 
def useranswer method end
@item_childs = ItemChild.where(:item_id => @item.id)
-> @useranswer = answersheet.where(:user_id => @user.id)

--------
@answer = Answer.where(:question_id => question.id)
--------

4. VIEW
multi.html.erb -> useranswer.html.erb

<%= form_tag multi_save_item_path do %>
  <% age_list = (18..30).to_a %>
  <ol>
    // 如果ic有東西，會送到def multi_save的 if params[:ic]，然後儲存。
    <li class="template"> 
      name<input data-name="ic[name][]"> ,
      age<select data-name="ic[age][]"><%= options_for_select(age_list) %></select>
      <span class="add">add</span>
      <span class="del">del</span>
    </li>
     
     //ic_old的[name]跟[age]有沒有送出去，有的話，會去CONTROLLER的if params[:ic_old]
    <% @item_childs.each do |old_ic| %>
      <li class="old_record">
        name<%= text_field_tag "ic_old[#{old_ic.id}][name]" , old_ic.name %> , name：顯示item_childs的name，值：是old_ic.name
        age<%= select_tag "ic_old[#{old_ic.id}][age]" , options_for_select(age_list , old_ic.age) %></select>
        <span class="add">add</span>
        <span class="del">del</span> 
      (<%= old_ic.id %>)
      </li>
    <% end %>
  </ol>
  <button type="submit">Submit</button>
<% end %>

=>=>=>
----------------------------------------------------------------------------------------------------
<%= form_tag useranswer_save_user_path do %>
 <%#= hidden_field_tag 'answersheet[answer_ids][]','' %>
    
  <ol>
    <% @question.each do |question| %> 
    回答新問題：
    <li> <%= label_tag question.id %> 
         <%= label_tag question.content %>
        
        <input type="radio" name="entry.361914725" value="不一定，只過某些特別有意義的節目" id="group_361914725_5" role="radio" class="ss-q-radio" aria-label="不一定，只過某些特別有意義的節目" required="" aria-required="true">
        
         <% question.answer.each do |answer| %> 
         
         name<input data-name="ic[name][]"> , 
         age<select data-name="ic[age][]"><%= options_for_select(age_list) %></select> <span class="add">add</span><span class="del">del</span></li>
         
         <input type="radio" name="ic[answer_id][]" value="answer.id">  <%= label_tag answer.content %> <span class="add">add</span><span class="del">del</span></li>
         
         <radio data-name="ic[answer_id][]" value="answer.id">  <%= label_tag answer.content %> <span class="add">add</span><span class="del">del</span></li>
    </li>
    
    <% @answersheet.each do |old_ic| %>
      <li>name<%= radio_button_tag "ic_old[#{old_ic.id}][name]" , old_ic.id %> ,
          age<%= select_tag "ic_old[#{old_ic.id}][age]" , options_for_select(age_list , old_ic.age) %></select>
          
          (<%= old_ic.id %>)
      </li>
    <% end %>
    
  </ol>
  <button type="submit">Submit</button>
<% end %>  
-------------------------------------------------------------------------------------------------------------------------

5. CONTROLLER 

def multi_save
    #取出所有關連id
    ids = (params[:ic_old] || {}).keys.map{|i|i.to_i}

    #語意：排除送出的id之外的所有隸屬item的都刪除
    ItemChild.where("item_id = #{@item.id} AND id NOT IN (#{ids.join(',')})").delete_all

    #更新舊的資料 ->>> ic_old的[name]跟[age]有沒有送出去，有的話，會去CONTROLLER的if params[:ic_old]
    if params[:ic_old]
      params[:ic_old].each_pair do |id , data|
        ic = ItemChild.where(:item_id => @item.id , :id => id).first
        if ic
          #這邊要過 permit 或是一個一個指定都行
          ic.update_attributes(:name => data[:name] , :age => data[:age])
        end
      end
    end

    #額外新增的都再塞入
    if params[:ic]
      params[:ic][:name].each_index do |index|
        ItemChild.create(:item_id => @item.id , :name => params[:ic][:name][index] , :age => params[:ic][:age][index])
      end
    end
    redirect_to :back
  end
  
  =>=>=>
  
  def multi_save
    #取出所有關連id
    ids = (params[:ic_old] || {}).keys.map{|i|i.to_i}

    #語意：排除送出的id之外的所有隸屬item的都刪除
    UserAnswer.where("user_id = #{@user.id} AND id NOT IN (#{ids.join(',')})").delete_all

    #更新舊的資料
    if params[:ic_old]
      params[:ic_old].each_pair do |id , data|
        ic = Answersheet.where(:user_id => @user.id , :id => id).first
        if ic
          #這邊要過 permit 或是一個一個指定都行
          ic.update_attributes(:answer_id => data[:answer_id])
        end
      end
    end

    #額外新增的都再塞入
    if params[:ic]
      params[:ic][:answer_id].each_index do |index|
        Answersheet.create(:user_id => @user.id , :answer_id => params[:ic][:answer_id][index])
      end
    end
    redirect_to :back
  end
---------------------------------
@answer = Answer.where(:question_id => question.id)

 <% age_list = (18..30).to_a %>
  <ol>
    <li class="template">
    name<input data-name="ic[name][]"> ,
    age<select data-name="ic[age][]"><%= options_for_select(age_list) %></select>
    <span class="add">add</span><span class="del">del</span>
    </li>
  
   @answer = Answer.where(:question_id => question.id)
   
   <ol>  
    <% @question.each do |question| %> 
    <%  @answer = Answer.where(:question_id => question.id) %>
    <li class="template">
    <%= label_tag question.id %> <%= label_tag question.content %>
     <select data-name="ic[answer_id][]"><%= options_for_select(@answer, "id", "name") %></select>
    <span class="add">add</span><span class="del">del</span>
    </li>
    <% end %>
   </ol>  
   
    select_tag "people", options_from_collection_for_select(@people, "id", "name")