ruby-on-rails - 如何修复 Heroku/Ruby on Rails 中的“ActionView::Template::Error”

Question

我跑了：

git add .
git commit -m "Some helpful message for your future self"

在我的终端。我还将我的 rails 应用程序推送到 Heroku 上，并且运行了：

heroku run rails db:migrate

我的应用程序显示“我们很抱歉，但出了点问题”。虽然错误。这是我的日志中显示的内容：

2019-07-28T00:08:13.687554+00:00 app[web.1]: F, [2019-07-28T00:08:13.687495 #4] FATAL -- : [b4dfe4a3-136d-499a-83f1-be0d4e82fb47] ActionView::Template::Error (No route matches {:action=>"show", :controller=>"categories", :id=>nil}, missing required keys: [:id]):
2019-07-28T00:08:13.687702+00:00 app[web.1]: F, [2019-07-28T00:08:13.687649 #4] FATAL -- : [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]     26:     <div class="center-one">
2019-07-28T00:08:13.687705+00:00 app[web.1]: [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]     27:       <table>
2019-07-28T00:08:13.687706+00:00 app[web.1]: [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]     28:         <tr>
2019-07-28T00:08:13.687708+00:00 app[web.1]: [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]     29:           <th class="table-header"><%= link_to 'community', category_path(@community) %></th>
2019-07-28T00:08:13.687710+00:00 app[web.1]: [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]     30:         </tr>
2019-07-28T00:08:13.687711+00:00 app[web.1]: [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]     31:         <tr>
2019-07-28T00:08:13.687713+00:00 app[web.1]: [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]     32:           <td>
2019-07-28T00:08:13.687741+00:00 app[web.1]: F, [2019-07-28T00:08:13.687697 #4] FATAL -- : [b4dfe4a3-136d-499a-83f1-be0d4e82fb47]   
2019-07-28T00:08:13.687806+00:00 app[web.1]: F, [2019-07-28T00:08:13.687747 #4] FATAL -- : [b4dfe4a3-136d-499a-83f1-be0d4e82fb47] app/views/categories/index.html.erb:29:in `_app_views_categories_index_html_erb___3528218001569079456_46996040052660'
2019-07-28T00:08:14.760735+00:00 heroku[router]: at=info method=GET path="/favicon.ico" host=damare.herokuapp.com request_id=78e904dc-8e9b-4849-ba3e-a137dd23ba60 fwd="71.140.151.125" dyno=web.1 connect=0ms service=1ms status=304 bytes=48 protocol=https

这是我的 categories_controller.rb 文件：

class CategoriesController < ApplicationController
  def index
    @categories = Category.all
    @community = @categories[0]
    @housing = @categories[1]
    @jobs = @categories[2]
    @personals = @categories[3]
    @services = @categories[4]
    @for_sale = @categories[5]
  end
  def show
    @listings = Listing.where(category_id: params[:id])
    @category = Category.find(params[:id])
  end
end

这是我的 routes.rb 文件：

Rails.application.routes.draw do
  devise_for :users
  resources :categories do
    resources :subcategories
  end
  resources :listings do
    collection do
      get 'search'
    end
  end
  root 'categories#index'
  match '/help', to: 'pages#help', via: :get
  match '/scams', to: 'pages#scams', via: :get
  match '/safety', to: 'pages#safety', via: :get
  match '/terms', to: 'pages#terms', via: :get
  match '/privacy', to: 'pages#privacy', via: :get
  match '/about', to: 'pages#about', via: :get
  match '/contact', to: 'pages#contact', via: :get
  match '/mylistings', to: 'listings#mylistings', via: :get
  match '/subcategoires/find_by_category', to: 'subcategories#find_by_category', via: :post
end

页面网址： https ://damare.herokuapp.com/

这些类别是在我的seeds.rb 文件中创建的：

community_category = Category.where(name: 'community').first_or_create(name: 'community')
housing_category = Category.where(name: 'housing').first_or_create(name: 'housing')
jobs_category = Category.where(name: 'jobs').first_or_create(name: 'jobs')
personals_category = Category.where(name: 'personals').first_or_create(name: 'personals')
services_category = Category.where(name: 'services').first_or_create(name: 'services')
for_sale_category = Category.where(name: 'for_sale').first_or_create(name: 'for sale')

子类别存储在社区类别中。子类别也在我的seeds.rb 文件中创建。以下是社区类别中的子类别：

Subcategory.where(name: 'activities', category_id: community_category.id).first_or_create(name: 'activities', category_id: community_category.id)
Subcategory.where(name: 'classes', category_id: community_category.id).first_or_create(name: 'classes', category_id: community_category.id)
Subcategory.where(name: 'events', category_id: community_category.id).first_or_create(name: 'events', category_id: community_category.id)
Subcategory.where(name: 'general', category_id: community_category.id).first_or_create(name: 'general', category_id: community_category.id)
Subcategory.where(name: 'new', category_id: community_category.id).first_or_create(name: 'news', category_id: community_category.id)
Subcategory.where(name: 'musicians', category_id: community_category.id).first_or_create(name: 'musicians', category_id: community_category.id)
Subcategory.where(name: 'pets', category_id: community_category.id).first_or_create(name: 'pets', category_id: community_category.id)

标签： ruby-on-railsrubyheroku

Answer 1

你这样声明@community变量：

@categories = Category.all
@community = @categories[0]

因此，当您的数据库中没有类别时@community是nil.

这会导致app/views/categories/index.html.erb:29您调用的位置出现问题category_path(@community)。因为@communityisnil它评估为category_path(nil). Hense 错误。

在显示此之前，您应该检查是否@community存在link。