无法确定为什么迭代不显示对象 - Ruby / ActiveRecord / Sinatra

Question

我通过ActiveRecord创建了两个表:Users和Paintings。我能够创建两个对象的实例。绘画与用户之间有belongs_to关系。用户与绘画之间存在has_many关系。当我尝试迭代用户的绘画列表时，没有任何反应。当我使用类似的惯例来迭代所有的绘画时，我没有遇到任何问题。

---

require './config/environment'
class ApplicationController < Sinatra::Base
configure do
set :public_folder, 'public'
set :views, 'app/views'
enable :sessions
set :session_secret, "extra_secret"
end
get '/' do
erb :index
end

helpers do
def logged_in?
!!current_user
end
def current_user
@current_user ||= User.find_by(id: session[:user_id]) if session[:user_id]
end
end 

end 

---

class UsersController < ApplicationController
get '/users/:slug' do
@user = User.find_by_slug(params[:slug])
erb :'users/user_homepage'
end
get '/signup' do
if !logged_in?
erb :'users/new_user'
else
redirect to '/'
end
end 
post '/signup' do
if params[:username] == "" || params[:email] == "" || params[:password] == ""
redirect to '/new_user'
else
@user = User.new(:username => params[:username], :email => params[:email], :password => params[:password])
@user.save
session[:user_id] = @user.id
redirect to '/user_homepage'
end
end

get '/login' do
if !logged_in?
erb :'users/login'
else
redirect '/index'
end
end
post '/login' do
user = User.find_by(:username => params[:username])
if user && user.authenticate(params[:password])
session[:user_id] = user.id
redirect to '/index'
else 
redirect to 'users/new_user'
end 
end 
get '/logout' do
if logged_in?
session.destroy
redirect to '/login'
else
redirect to '/'
end
end
end 

---

class PaintingsController < ApplicationController
get '/index' do
if logged_in?
@paintings = Painting.all
erb :'paintings/index'
else
redirect to '/login'
end 
end
get "/new" do  #create get
erb :'paintings/new'
end 
post "/new" do  #create post
Painting.create(params)
redirect "/user_homepage"
end

post '/user_homepage' do #changed from /index to /user_homepage. Did not fix.
if logged_in?
if params[:name] == ""
redirect to "/new"
else
@painting = current_user.paintings.build(name: params[:name])
if @painting.save
redirect to "/index/#{@painting.id}"
else
redirect to "/new"
end
end
else
redirect to '/login'
end
end  

get "/paintings/:id/edit" do #update get
if logged_in?
@painting = Painting.find_by_id(params[:id])
if @painting && @painting.user == current_user
erb :'paintings/edit_tweet'
else
redirect to '/user_homepage'
end
else
redirect to '/login'
end
end
post "/paintings/:id" do #update post
@painting = Painting.find(params[:id])
@painting.update(params.select{|p| p=="name" || p=="year" || p=="artist_id"})
redirect "/paintings/#{@painting.id}"
end

get "/paintings/:id" do #read get
@painting = Painting.find(params[:id])
erb :'paintings/show'
end
get '/user_homepage' do
if logged_in?
erb :'users/user_homepage'
else
redirect '/index'
end
end 

#Need post /user_homepage to show users paintings?
end 

---

#视图不显示用户画作

<h1> User Homepage </h1>
<h2>Welcome <%= current_user.username %>!</h2>
<p> Below is a list of your favorite paintings: </p>

<% @current_user.paintings.each do |painting| %>
<div>
Name: <%= painting.painting_name %>
Year: <%= painting.year %>
</div>

<% end %>
<p> <a href="/new"> Add New Painting</a>
<p> <a href="/index"> Click here to see today's popular paintings! </a> </p>

---

ActiveRecord::Schema.define(version: 2021_03_03_151621) do
create_table "paintings", force: :cascade do |t|
t.string "painting_name"
t.string "year"
t.integer "artist_id"
t.integer "user_id"
end
create_table "users", force: :cascade do |t|
t.string "username"
t.string "email"
t.string "password_digest"
end
end

---

class Painting < ActiveRecord::Base
belongs_to :user

end

---

class User < ActiveRecord::Base

has_secure_password
has_many :paintings
def slug
username.downcase.gsub(" ","-")
end
def self.find_by_slug(slug)
User.all.find{|user| user.slug == slug}
end
end 

Answer 1

看起来您可能在打算使用@user的地方使用current_user。

这是你的用户主页行动:

@user = User.find_by_slug(params[:slug])
erb :'users/user_homepage'

但是视图中有

@current_user.paintings

---

另一个要检查的选项是(我不是Sinatra专家)，helper是暴露给视图的，而不是底层的实例变量，所以您需要使用

current_user.paintings