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

Question

I'm creating a website where users can post their items & services for sale (a classified ads site) and have setup the 'listing', 'category', and 'user' models. The listings and categories are associated with each other in a "has_many"-->"belongs_to" relationship, with categories owning listings.

However, even though the Listings are successfully associating with a Category upon creation of a new listing (I believe...?), the "show" page for Categories is not displaying it's associated listings; (displaying the "No listings to display" message"). What could be the problem?

-Here's my 'show' page for Categories:

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

-and here's the controller for Categories:

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

-Here's the controller for Listings:

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

-This is listing partial referenced in the show page:

<% 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 %>

-The model file for listing:

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

-The model file for category:

class Category < ActiveRecord::Base
  has_many :listings
end

Stanislav Mekhonoshin Stanislav Mekhonoshin · Accepted Answer · 2015-02-03T17:23:52

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

Makes listings avalable via listings var, not @listings, as in your template.

Just remove @ sign.

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

1 Answers