ruby-on-rails - 我的测试正在通过。但是，未定义的方法 `reviews' 为 nil :NilClass when calling the page

Question

大家下午好

我正在尝试构建一个烟草审查应用程序，只是为了学习更多的东西。我一直试图建立在我在 Rails 教程书中学到的东西的基础上，但是我不断遇到我不理解的砖墙和陷阱。对于 nil:NilClass 和我遇到的其他问题，我通常可以克服未定义的方法“something”，但这个问题真的让我感到困惑，因为我的测试通过了。

我的测试

review_test.rb

require 'test_helper'

class ReviewTest < ActiveSupport::TestCase

# Define a user for the test
def setup
@user = users(:shaun)
@review = @user.reviews.build( rating: 5, 
                               comment:"This is a super snus",
                               tobacco_id: 1)
end

# Test should be valid
test "should be valid" do
    assert @review.valid?
end

# Test the user id is present
test "user id should be present" do
    @review.user_id = nil
    assert_not @review.valid?
end

# Test the tobacco id is present
test "tobacco id should be present"  do 
    @review.tobacco_id = nil
    assert_not @review.valid?
end

# Rating should be present
test "rating should be present" do
    @review.rating = "   "
    assert_not @review.valid?
end

# Comment should be present
test "comment should be present" do 
    @review.comment = "    "
    assert_not @review.valid?
end

# Verify that the first review in the DB is the same as fixture review
test "order should be most recent first" do
    assert_equal reviews(:most_recent), Review.first
end

end

user_test.rb

# Test that a review is destroyed when a user is destroyed
test "associated reviews should be destroyed" do 
@user.save
@user.reviews.create!( rating: 5,
                       comment: "I love this suns, it's so good!",
                       tobacco_id: 1)
assert_difference 'Review.count', -1 do 
    @user.destroy
end
end

灯具

评论.yml

one:
rating: 5
tobacco_id: 1
comment: "This is a super snus"
created_at: <%= 3.hours.ago %>

two:
rating: 5
tobacco_id: 1
comment: "This is the best snus in the world"
created_at: <%= 2.hours.ago %>

three:
rating: 5
tobacco_id: 1
comment: "I will always buy this snus"
created_at: <%= 1.hours.ago %>

 most_recent:
 rating: 5
 tobacco_id: 1
 comment: "I have a shed load of this snus, it's great!"
 created_at: <%= Time.zone.now %>

型号

review.rb

belongs_to :tobacco

烟草.rb

has_many :reviews

user.rb

has_many :tobaccos, dependent: :destroy
has_many :reviews, dependent: :destroy

Controller
review_controller.rb

def new
@review = Review.new
end

这是我在 Controller 中创建操作的内容，但我不知道我是否正确，因为我还无法加载页面。如果我有这个错误，我将不胜感激任何关于创建操作的建议，以避免问另一个问题，我可能有!

def create
    @tobacco = Tobacco.find(params[:tobacco_id])
    @review = @tobacco.reviews.new(params[:review].permit(:tobacco_id, :comment))
    @review.user = User.find(current_user.id)
    @review.save
    redirect_to tobacco_path(@tobacco)
end

路线

resources :tobaccos do 
resources :reviews, except: [:show, :index]
end

show.html.erb

<%= link_to "Write a Review", new_tobacco_review_path(@tobacco) %>

new.html.erb

<%= form_for([@tobacco, @tobacco.reviews.build]) do |f| %>
<%= render 'fields', f: f %>
<%= f.submit "Save Review", class: 'btn btn-primary' %>
<% end %>

当我进入页面写评论时，我收到错误

Showing C:/Sites/apps/review/app/views/reviews/new.html.erb where line #11 raised:

undefined method `reviews' for nil:NilClass

它告诉我这是第 11 行

<%= form_for([@tobacco, @tobacco.reviews.build]) do |f| %>

但无论我尝试什么，我都会遇到不同的错误。我知道这是菜鸟的错误，但我看不到。

提前致谢

肖恩

更新

我已经让它工作并现在保存到数据库中，我是这样做的
在 review_controller.rb 中，新的和创建的看起来像这样

def new
    @tobacco = Tobacco.find(params[:tobacco_id])
end


def create

@tobacco = Tobacco.find(params[:tobacco_id])
@review = Review.new(review_params)
@review.user_id = current_user.id
@review.tobacco_id = @tobacco.id

if @review.save
  redirect_to @tobacco
else
  render 'new'
end
end

review_params 是

def review_params
    params.require(:review).permit(:rating, :comment, :tobacco_id)
end

对我来说，这一切看起来都不错，而且很有效，所以我希望一切顺利。

我现在被困在编辑属于烟草的评论。这是我第一次处理嵌套路由。我只是看了几个教程，但没有什么能真正帮助我解决这个问题。我不确定如何传递这些 key ...

在节目页面上我有这个

<%= link_to "Edit", edit_tobacco_review_path(@tobacco, @review) %>

显示方法烟草_ Controller .rb 看起来像这样

def show
    @tobacco = Tobacco.find(params[:id])
    @reviews = Review.where(tobacco_id: @tobacco.id)
end

在 review_controller.rb 我有这个

def edit
    @tobacco = Tobacco.find(params[:tobacco_id])
    @review  = Review.find(params[:id])
end

我得到的错误是这个

ActionController::UrlGenerationError in Tobaccos#show
No route matches {:action=>"edit", :controller=>"reviews", :id=>nil, :tobacco_id=>"8"} missing required keys: [:id]

看着这个，我应该在 Tobaccos#show 行动中做点什么，但我想不出是什么。

我快回家了，你能看出我做错了什么吗？谢谢 :)

更新编号 2 show.html.erb
这不是整个节目页面，但它是重要的部分

<% if @reviews.blank? %>
    <h3>No reviews yet! Would you like to be the first?</h3>
    <%= link_to "Write Review", new_tobacco_review_path(@tobacco), class: "btn btn-danger" %>
<% else %>
    <% @reviews.each do |review| %>
 <div class="reviews">
    <p><%= review.comment %></p>
    <p><%= review.user.name %></p>
    <%= link_to "Edit", edit_tobacco_review_path(@tobacco, @review) %>
</div>
   <% end %>
<%= link_to "Write Another Review", new_tobacco_review_path(@tobacco), class: "btn btn-danger" %>
<% end %>

更新编号 3 edit.html.erb

<%= form_for([@tobacco, @tobacco.reviews.build]) do |f| %>
<%= render 'fields', f: f %>
<%= f.submit "Update Review", class: 'btn btn-primary' %>
<% end %>
<%= link_to "Back", tobacco_path(@tobacco), 
class: "btn btn-default btn-block margin-top-25" %>

_fields.html.erb

<%= f.label  :rating %>
<%= f.select :rating, [['1', 1], 
                   ['2', 2], 
                   ['3', 3], 
                   ['4', 4], 
                   ['5', 5]
                  ] ,class: 'form-control' %>

<%= f.label :comment %>
<%= f.text_field :comment, class: 'form-control' %>

Answer 1

ActionController::UrlGenerationError in Tobaccos#show No route matches {:action=>"edit", :controller=>"reviews", :id=>nil, :tobacco_id=>"8"} missing required keys: [:id

你在迭代 @reviews如 review ， 所以

这条线

<%= link_to "Edit", edit_tobacco_review_path(@tobacco, @review) %>

应该

<%= link_to "Edit", edit_tobacco_review_path(@tobacco, review) %>