ruby-on-rails - Ruby on Rails ActiveRecord 数据流

Question

我目前正在尝试构建一个类似于 Trello 的应用程序.我有可以创建 boards 的 users。每个用户都可以拥有不同的角色，具体取决于他们所在的版 block 。因为我是 Rails 的新手，所以我只想确保我遵循“Rails 方式”和最佳实践。这是我的架构:

create_table "boards", force: :cascade do |t|
    t.string "title"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "user_boards", force: :cascade do |t|
    t.integer "user_id"
    t.integer "board_id"
    t.integer "role"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "users", force: :cascade do |t|
    t.string "name"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.string "email", default: "", null: false
    t.string "encrypted_password", default: "", null: false
    t.string "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer "sign_in_count", default: 0, null: false
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.inet "current_sign_in_ip"
    t.inet "last_sign_in_ip"
    t.index ["email"], name: "index_users_on_email", unique: true
    t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
  end

  add_foreign_key "lists", "boards"

如您所见，我将 role 属性添加到 UserBoard 连接表。一个 User has_many Boards 和 Board has_many Users 都 through: UserBoard。根据用户和董事会，他们可以有不同的角色。

用户板.rb

class UserBoard < ApplicationRecord
  belongs_to :user
  belongs_to :board
  enum role: { admin: 0, member: 1 }
end

用户.rb

class User < ApplicationRecord
  has_many :user_boards
  has_many :boards, through: :user_boards
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable
  validates :name, presence: true, length: { maximum: 50 }
  validates :email, presence: true
end

棋盘.rb

class Board < ApplicationRecord
  has_many :user_boards
  has_many :users, through: :user_boards
  has_many :lists, dependent: :destroy
  include AssociateUsersToBoards

  def self.assign_board_to_user(user, board)
    AssociateUsersToBoards.build_association(user, board)
  end
end

我只是想弄清楚这是否是处理此问题的最佳方法，以及是否有更好的方法来设置它，以便我的查询和更新可以更清晰一些。现在，当 User 创建一个 Board 时，您可以看到我正在使用 ActiveRecord:create 函数。我使用 create 的原因是因为当我尝试使用 new 或 build 时，连接表中的关联没有得到。这对我来说似乎是错误的，我将无法执行 current_user.boards.new(board_params) 或 current_user.boards.build(board_params):

def create
  @board = current_user.boards.new(board_params)

  respond_to do |format|
    if current_user.save
      format.html { redirect_to @board, notice: 'Board was successfully created.' }
      format.json { render :show, status: :created, location: @board }
    else
      format.html { render :new }
      format.json { render json: @board.errors, status: :unprocessable_entity }
    end
  end
end

但我还想将 role 设置为 admin.. 我能想到的唯一方法是 current_user.user_boards.find_by(board_id: @board).update_attribute(:role, 'admin') 在我将记录保存到我的 board#create 操作之后。这个查询有点让我想吐，我不敢相信没有更好的方法。

我的 board_params 非常简单 & 只允许基本标题:

def board_params
  params.require(:board).permit(:title)
end

---

编辑

---

我还想添加我用来提交 board 的表单，以确保其中没有任何错误:

<div class="modal-body">
  <%= form_with(model: board, local: true) do |form| %>
    <% if board.errors.any? %>
      <div id="error_explanation">
        <h2><%= pluralize(board.errors.count, "error") %> prohibited this board from being saved:</h2>

        <ul>
          <% board.errors.full_messages.each do |message| %>
            <li><%= message %></li>
          <% end %>
        </ul>
      </div>
    <% end %>

    <div class="form-group">
      <%= form.label :title %><br/>
      <%= form.text_field :title, autofocus: true, class: 'form-control' %>
    </div>

    <div class="actions">
      <%= form.submit 'Create Board', class: 'btn btn-small btn-success btn-block' %>
    </div>
  <% end %>
</div>

非常感谢所有建议、提示和建设性批评，因为我尝试越来越多地学习/熟悉 Ruby 语言和 Rails 框架。

Answer 1

你没有显示 board_params，但也许它看起来应该是这样的:

def board_params
  params.require(:board).permit(:something, :whatever_else).merge!(role: :admin)
end

然后，做类似的事情:

def create
  @board = current_user.boards.new(board_params)

  respond_to do |format|
    if @board.save
      format.html { redirect_to @board, notice: 'Board was successfully created.' }
      format.json { render :show, status: :created, location: @board }
    else
      format.html { render :new }
      format.json { render json: @board.errors, status: :unprocessable_entity }
    end
  end
end

这应该会创建一个正确设置了 user_id 和 role 的新看板。

顺便说一句，我个人更喜欢:

class UserBoard < ApplicationRecord
  belongs_to :user
  belongs_to :board
  enum role: {
    admin:  0,
    member: 1
  }
end

所以我不必担心 enum 在数组中的位置，如 docs 中讨论的那样:

Note that when an array is used, the implicit mapping from the values to database integers is derived from the order the values appear in the array. In the example, :active is mapped to 0 as it's the first element, and :archived is mapped to 1. In general, the i-th element is mapped to i-1 in the database.

Therefore, once a value is added to the enum array, its position in the array must be maintained, and new values should only be added to the end of the array. To remove unused values, the explicit hash syntax should be used.