在Rails 4中用AJAX替換部分代碼：未定義的方法`id`

Question

通過Ajax替換部分代碼時，一種方法給我適當的結果，而另一種（幾乎完全相同）卻沒有。 我想選擇和取消選擇特定廣告系列的組。 選擇可以直接替換，取消選擇則不能。

模型/general_connection.rb

belongs_to :campaign
belongs_to :group

型號/group.rb

has_many :general_connections
has_many :campaigns, through: :general_connections

型號/campaign.rb

has_many :general_connections
has_many :groups, through: :general_connections

控制器/general_connection.rb

def connect_group_to_campaign
  @group = Group.find(params[:group_id])
  @campaign = Campaign.find(params[:campaign_id])
  @campaign.general_connections.create(group: @group)
  respond_to do |format|
        format.html { redirect_to :back }
        format.js
  end
end

def disconnect_group_from_campaign
  @general_connection = GeneralConnection.where("group_id = ? AND campaign_id = ?", params[:group_id], params[:campaign_id]).first
  @group = @general_connection.group

  @general_connection.destroy
  respond_to do |format|
        format.html { redirect_to :back }
        format.js
  end
end

views / campaign / show.html.erb

<div class="row">
    <% @main_groups.each do |group| %>
        <%= render partial: 'groups_form', locals: { group: group } %>
    <% end %>
</div>

* views / campaign / _groups_form.html.erb

<div class="row" id="group_<%= group.id %>">
    <div class="col m6">
        <div class="valign-wrapper black-text">
            <% if group.icon.nil? %>
                <i class="material-icons">group</i>
            <% else %>
                <i class="material-icons"><%= group.icon %></i>
            <% end %>
                &nbsp;&nbsp<%= group.title %>
        </div>
    </div>
    <div class="col m6">
        <% if !grouped(group) %>                
            <%= form_tag connect_group_to_campaign_path(:group_id => group.id, :campaign_id => @campaign.id), remote: true do %>
                <%= button_tag 'check_box_outline_blank', class: "secondary-content material-icons grey-text", style: "background-color:white;border:none;" %>
            <% end %>
        <% else %>
            <%= form_tag disconnect_group_from_campaign_path(:group_id => group.id, :campaign_id => @campaign.id), remote: true do %>
                <%= button_tag 'check_box', class: "secondary-content material-icons grey-text", style: "background-color:white;border:none;" %>
            <% end %>
        <% end %>
    </div>
</div>

views / general_connection / connect_group_to_campaign.js.erb

$('#group_<%= @group.id %>').replaceWith('<%= j render partial: 'campaigns/groups_form', locals: {group: @group} %>');

views / general_connection / disconnect_group_from_campaign.js.erb

$('#group_<%= @group.id %>').replaceWith('<%= j render partial: 'campaigns/groups_form', locals: {group: @group} %>');

...這是我得到的錯誤：

ActionView::Template::Error (undefined method `id' for nil:NilClass):
12:                     </div>
13:                     <div class="col m6">
14:                         <% if !grouped(group) %>                
15:                             <%= form_tag connect_group_to_campaign_path(:group_id => group.id, :campaign_id => @campaign.id), remote: true do %>
16:                                 <%= button_tag 'check_box_outline_blank', class: "secondary-content material-icons grey-text", style: "background-color:white;border:none;" %>
17:                             <% end %>
18:                         <% else %>

概括起來：這兩種方法都工作，但只有connect_group_to_campaign給出了一個直接結果， disconnect_group_from_campaign不和需要刷新瀏覽器。

誰能幫我嗎？

Answer 1

似乎@campaign對象未在disconnect_group_from_campaign方法中聲明。 在您的disconnect_group_from_campaign方法中添加以下行之后，嘗試一下

@campaign = Campaign.find(params[:campaign_id])