'Categories' 显示操作未显示关联的 'Listings'（Ruby 在 Rails 上）

Question

我正在创建一个网站，用户可以在其中 post 出售他们的商品和服务（分类广告网站）并设置了 'listing'、'category' 和 'user' 模型。列表和类别以 "has_many"-->"belongs_to" 关系相互关联，类别拥有列表。

但是，即使在创建新列表时列表已成功与类别关联（我相信......？），"show" 页面类别未显示其关联列表；（显示 "No listings to display" 消息”）。可能是什么问题？

-这是我的 'show' 类别页面：

<h1><%= @category.name %></h1>
<%= render partial: 'listings/list', locals: {
listings: @category.listings } %>

-这是类别的控制器：

class CategoriesController < ApplicationController
  def show
    @category = Category.find(params[:id])
  end
end

-这是列表的控制器：

class ListingsController < ApplicationController
  before_action :logged_in_user, only: [:create, :destroy]
  before_action :correct_user,   except: [:create, :index, :new]

  def index
    @listings = Listing.all
  end

  def show
  end

  def new
    @listing = Listing.new
  end

  def edit
  end

  def create
    @listing = current_user.listings.build(listing_params)
    if @listing.save
      redirect_to @listing
      flash[:success] = "Listing was successfully created."
    else
      render 'new'
    end
  end

  def update
    if @listing.update(listing_params)
      flash[:success] = "Listing was successfully updated."
      redirect_to @listing
    else
      render 'edit'
    end
  end

  def destroy
    @listing.destroy
    flash[:success] = "Listing deleted."
    redirect_to request.referrer || root_url
  end

  private

    def listing_params
      params.require(:listing).permit(:name, :description, :price, :image,
      :category_id)

    def correct_user
      @listing = current_user.listings.find_by(id: params[:id])
      redirect_to root_url if @listing.nil?
    end
end

-这是展示页面中部分引用的列表：

<% if @listings.nil? %>
  No listings to display! Go <%= link_to 'create one', new_listing_path %>.
<% else %>
  <table class="table table-striped">
    <tbody>
      <% @listings.each do |listing| %>
        <tr>
          <td><%= link_to listing.name, listing %></td>
          <td class="text-right">
            <% if listing.price %>
              <%= number_to_currency(listing.price) %>
            <% end %>
          </td>
          <td class="text-right">
            <% @listings.each do |listing| %>
              <% if listing.category %>
                <%= link_to listing.category.name, listing.category %>
              <% end %>
            <% end %>
          </td>
        </tr>
      <% end %>
    </tbody>
  </table>
<% end %>

-上市模型文件：

class Listing < ActiveRecord::Base
  belongs_to :user
  belongs_to :category
  default_scope -> { order('created_at DESC') }
  validates :name, presence: true
  validates :description, presence: true
  validates :price, presence: true
  validates :user_id, presence: true
  mount_uploader :image, ImageUploader
end

-类别的模型文件：

class Category < ActiveRecord::Base
  has_many :listings
end

Answer 1

<%= render partial: 'listings/list', locals: {
listings: @category.listings } %>

通过 listings var 使列表可用，而不是像在您的模板中那样 @listings。

只需删除@符号。

'Categories' 显示操作未显示关联的 'Listings'（Ruby 在 Rails 上）

'Categories' show action isn't displaying associated 'Listings' (Ruby on Rails)

ruby

ruby-on-rails

view

model-associations