“1 个错误禁止保存：用户不能为空”- Hartl Ruby Rails 教程
"1 error prohibiting this from being saved: User can't be blank" - Hartl Ruby on Rails Tutorial
我正在学习 Hartl Rails 教程，到目前为止已经创建了 2 个模型：一个 'User' 模型和一个 'Listing' 模型（本质上是 'Microposts' 模型，除了自定义为更像 Craigslist 类型的 post/advertisement 而不是 Twitter 类型的状态更新）。
我已经使用“belongs_to :user”设置了“listing.rb”模型，并且还有带有“has_many :listings, dependent: destroy”的“user.rb”模型，甚至给出 'listings' a user_id index and and created_at index.
但是，每当我尝试创建新列表并提交时，我都会收到以下错误：
“1 个错误，禁止保存此列表：用户不能为空”。
没有出现其他错误，这让我假设 'listing' 的其他列是必需的（名称、描述、价格和可选图片），但由于某种原因 User_id 没有附加到创建的列表？
这是什么原因？
这是我的 user.rb、listing.rb 和 schema.rb 以及控制器：
schema.rb:
ActiveRecord::Schema.define(version: 20150223175136) do
create_table "categories", force: true do |t|
t.string "name"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "listings", force: true do |t|
t.string "name"
t.text "description"
t.decimal "price"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "image"
t.integer "user_id"
t.integer "category_id"
t.string "username"
end
add_index "listings", ["user_id", "created_at"], name: "index_listings_on_user_id_and_created_at"
add_index "listings", ["user_id"], name: "index_listings_on_user_id"
add_index "listings", ["username"], name: "index_listings_on_username"
create_table "users", force: true do |t|
t.string "email"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "password_digest"
t.string "remember_digest"
t.boolean "admin", default: false
t.string "activation_digest"
t.boolean "activated", default: false
t.datetime "activated_at"
t.string "reset_digest"
t.datetime "reset_sent_at"
t.string "username"
t.string "first_name"
t.string "last_name"
end
add_index "users", ["email"], name: "index_users_on_email", unique: true
end
user.rb:
class User < ActiveRecord::Base
has_many :listings, dependent: :destroy
attr_accessor :remember_token, :activation_token, :reset_token
before_save :downcase_email
before_create :create_activation_digest
validates :first_name, presence: true, length: { maximum: 25 }
validates :last_name, presence: true, length: { maximum: 50 }
validates :username, presence: true, uniqueness: true, length: {maximum: 50 }
VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
validates :email, presence: true, length: { maximum: 255 },
format: { with: VALID_EMAIL_REGEX },
uniqueness: { case_sensitive: false }
has_secure_password
validates :password, length: { minimum: 6 }, allow_blank: true
class << self
# Returns the hash digest of the given string.
def digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Engine.cost
BCrypt::Password.create(string, cost: cost)
end
# Returns a random token.
def new_token
SecureRandom.urlsafe_base64
end
end
# Remembers a user in the database for use in persistent sessions.
def remember
self.remember_token = User.new_token
update_attribute(:remember_digest, User.digest(remember_token))
end
# Returns true if the given token matches the digest.
def authenticated?(attribute, token)
digest = send("#{attribute}_digest")
return false if digest.nil?
BCrypt::Password.new(digest).is_password?(token)
end
# Forgets a user.
def forget
update_attribute(:remember_digest, nil)
end
# Activates an account.
def activate
update_attribute(:activated, true)
update_attribute(:activated_at, Time.zone.now)
end
# Sends activation email.
def send_activation_email
UserMailer.account_activation(self).deliver_now
end
# Sets the password reset attributes.
def create_reset_digest
self.reset_token = User.new_token
update_attribute(:reset_digest, User.digest(reset_token))
update_attribute(:reset_sent_at, Time.zone.now)
end
# Sends password reset email.
def send_password_reset_email
UserMailer.password_reset(self).deliver_now
end
# Returns true if a password reset has expired.
def password_reset_expired?
reset_sent_at < 2.hours.ago
end
private
# Converts email to all lower-case.
def downcase_email
self.email = email.downcase
end
# Creates and assigns the activation token and digest.
def create_activation_digest
self.activation_token = User.new_token
self.activation_digest = User.digest(activation_token)
end
end
listing.rb:
class Listing < ActiveRecord::Base
belongs_to :user
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
这是“列表”控制器：
class ListingsController < ApplicationController
before_action :logged_in_user, only: [:create, :destroy]
before_action :correct_user, only: :destroy
def index
@listings = Listing.all
end
def show
end
def new
@listing = Listing.new
end
def edit
end
def create
@listing = Listing.new(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)
end
def correct_user
@listing = current_user.listings.find_by(id: params[:id])
redirect_to root_url if @listing.nil?
end
end
和'Users'控制器：
class UsersController < ApplicationController
before_action :logged_in_user, only: [:index, :edit, :update, :destroy]
before_action :correct_user, only: [:edit, :update]
before_action :admin_user, only: :destroy
def show
@user = User.find(params[:id])
end
def index
@users = User.paginate(page: params[:page])
end
def new
@user = User.new
end
def create
@user = User.new(user_params)
if @user.save
@user.send_activation_email
flash[:info] = "Please check your email to activate your account."
redirect_to root_url
else
render 'new'
end
end
def edit
@user = User.find(params[:id])
end
def update
@user = User.find(params[:id])
if @user.update_attributes(user_params)
flash[:success] = "Profile updated"
redirect_to @user
else
render 'edit'
end
end
def destroy
User.find(params[:id]).destroy
flash[:success] = "User deleted"
redirect_to users_url
end
private
def user_params
params.require(:user).permit(:first_name, :last_name, :username, :email,
:password, :password_confirmation)
end
# Before filters
# Confirms the correct user.
def correct_user
@user = User.find(params[:id])
redirect_to(root_url) unless current_user?(@user)
end
# Confirms an admin user.
def admin_user
redirect_to(root_url) unless current_user.admin?
end
end
我不熟悉您正在学习的教程，但用户不会自动附加到新创建的列表，您需要明确地执行此操作。在 ListingsController 的 create 操作中，将第一行替换为以下内容：
@listing = current_user.listings.build(listing_params)
在这种情况下，Listing 通过 listings 关联获得构建（尚未保存），并且 current_user 自动设置为 user。你也可以这样做：
@listing = Listing.new(listing_params)
@listing.user = current_user
但更喜欢较短的版本。
我正在学习 Hartl Rails 教程，到目前为止已经创建了 2 个模型：一个 'User' 模型和一个 'Listing' 模型（本质上是 'Microposts' 模型，除了自定义为更像 Craigslist 类型的 post/advertisement 而不是 Twitter 类型的状态更新）。
我已经使用“belongs_to :user”设置了“listing.rb”模型，并且还有带有“has_many :listings, dependent: destroy”的“user.rb”模型，甚至给出 'listings' a user_id index and and created_at index.
但是，每当我尝试创建新列表并提交时，我都会收到以下错误：
“1 个错误，禁止保存此列表：用户不能为空”。
没有出现其他错误，这让我假设 'listing' 的其他列是必需的（名称、描述、价格和可选图片），但由于某种原因 User_id 没有附加到创建的列表？
这是什么原因？
这是我的 user.rb、listing.rb 和 schema.rb 以及控制器：
schema.rb:
ActiveRecord::Schema.define(version: 20150223175136) do
create_table "categories", force: true do |t|
t.string "name"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "listings", force: true do |t|
t.string "name"
t.text "description"
t.decimal "price"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "image"
t.integer "user_id"
t.integer "category_id"
t.string "username"
end
add_index "listings", ["user_id", "created_at"], name: "index_listings_on_user_id_and_created_at"
add_index "listings", ["user_id"], name: "index_listings_on_user_id"
add_index "listings", ["username"], name: "index_listings_on_username"
create_table "users", force: true do |t|
t.string "email"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "password_digest"
t.string "remember_digest"
t.boolean "admin", default: false
t.string "activation_digest"
t.boolean "activated", default: false
t.datetime "activated_at"
t.string "reset_digest"
t.datetime "reset_sent_at"
t.string "username"
t.string "first_name"
t.string "last_name"
end
add_index "users", ["email"], name: "index_users_on_email", unique: true
end
user.rb:
class User < ActiveRecord::Base
has_many :listings, dependent: :destroy
attr_accessor :remember_token, :activation_token, :reset_token
before_save :downcase_email
before_create :create_activation_digest
validates :first_name, presence: true, length: { maximum: 25 }
validates :last_name, presence: true, length: { maximum: 50 }
validates :username, presence: true, uniqueness: true, length: {maximum: 50 }
VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
validates :email, presence: true, length: { maximum: 255 },
format: { with: VALID_EMAIL_REGEX },
uniqueness: { case_sensitive: false }
has_secure_password
validates :password, length: { minimum: 6 }, allow_blank: true
class << self
# Returns the hash digest of the given string.
def digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Engine.cost
BCrypt::Password.create(string, cost: cost)
end
# Returns a random token.
def new_token
SecureRandom.urlsafe_base64
end
end
# Remembers a user in the database for use in persistent sessions.
def remember
self.remember_token = User.new_token
update_attribute(:remember_digest, User.digest(remember_token))
end
# Returns true if the given token matches the digest.
def authenticated?(attribute, token)
digest = send("#{attribute}_digest")
return false if digest.nil?
BCrypt::Password.new(digest).is_password?(token)
end
# Forgets a user.
def forget
update_attribute(:remember_digest, nil)
end
# Activates an account.
def activate
update_attribute(:activated, true)
update_attribute(:activated_at, Time.zone.now)
end
# Sends activation email.
def send_activation_email
UserMailer.account_activation(self).deliver_now
end
# Sets the password reset attributes.
def create_reset_digest
self.reset_token = User.new_token
update_attribute(:reset_digest, User.digest(reset_token))
update_attribute(:reset_sent_at, Time.zone.now)
end
# Sends password reset email.
def send_password_reset_email
UserMailer.password_reset(self).deliver_now
end
# Returns true if a password reset has expired.
def password_reset_expired?
reset_sent_at < 2.hours.ago
end
private
# Converts email to all lower-case.
def downcase_email
self.email = email.downcase
end
# Creates and assigns the activation token and digest.
def create_activation_digest
self.activation_token = User.new_token
self.activation_digest = User.digest(activation_token)
end
end
listing.rb:
class Listing < ActiveRecord::Base
belongs_to :user
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
这是“列表”控制器：
class ListingsController < ApplicationController
before_action :logged_in_user, only: [:create, :destroy]
before_action :correct_user, only: :destroy
def index
@listings = Listing.all
end
def show
end
def new
@listing = Listing.new
end
def edit
end
def create
@listing = Listing.new(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)
end
def correct_user
@listing = current_user.listings.find_by(id: params[:id])
redirect_to root_url if @listing.nil?
end
end
和'Users'控制器：
class UsersController < ApplicationController
before_action :logged_in_user, only: [:index, :edit, :update, :destroy]
before_action :correct_user, only: [:edit, :update]
before_action :admin_user, only: :destroy
def show
@user = User.find(params[:id])
end
def index
@users = User.paginate(page: params[:page])
end
def new
@user = User.new
end
def create
@user = User.new(user_params)
if @user.save
@user.send_activation_email
flash[:info] = "Please check your email to activate your account."
redirect_to root_url
else
render 'new'
end
end
def edit
@user = User.find(params[:id])
end
def update
@user = User.find(params[:id])
if @user.update_attributes(user_params)
flash[:success] = "Profile updated"
redirect_to @user
else
render 'edit'
end
end
def destroy
User.find(params[:id]).destroy
flash[:success] = "User deleted"
redirect_to users_url
end
private
def user_params
params.require(:user).permit(:first_name, :last_name, :username, :email,
:password, :password_confirmation)
end
# Before filters
# Confirms the correct user.
def correct_user
@user = User.find(params[:id])
redirect_to(root_url) unless current_user?(@user)
end
# Confirms an admin user.
def admin_user
redirect_to(root_url) unless current_user.admin?
end
end
我不熟悉您正在学习的教程，但用户不会自动附加到新创建的列表，您需要明确地执行此操作。在 ListingsController 的 create 操作中，将第一行替换为以下内容：
@listing = current_user.listings.build(listing_params)
在这种情况下，Listing 通过 listings 关联获得构建（尚未保存），并且 current_user 自动设置为 user。你也可以这样做：
@listing = Listing.new(listing_params)
@listing.user = current_user
但更喜欢较短的版本。