Rails 4 has_many :through relationship: 将默认值分配给从父模型创建操作时加入模型属性

Question

我有三个型号：

class User < ActiveRecord::Base
  has_many :administrations
  has_many :calendars, through: :administrations
end

class Calendar < ActiveRecord::Base
  has_many :administrations
  has_many :users, through: :administrations
end

class Administration < ActiveRecord::Base
  belongs_to :user
  belongs_to :calendar
end

备注：我在User模型上使用Devise进行身份验证。

连接 Administration 模型具有以下属性：

id
user_id
calendar_id
role

这是我当前的路线：

devise_for :users, :path => 'account'

resources :users do
  resources :calendars
end

这是我的 calendars_controller:

class CalendarsController < ApplicationController
  before_action :set_calendar, only: [:show, :edit, :update, :destroy]
  before_action :authenticate_user!

  # GET /calendars
  # GET /calendars.json
  def index
    @user = current_user
    @calendars = Calendar.all
  end

  # GET /calendars/1
  # GET /calendars/1.json
  def show
    @user = current_user
    @calendar = Calendar.find(params[:id])
  end

  # GET /calendars/new
  def new
    @user = current_user
    @calendar = @user.calendars.new
  end

  # GET /calendars/1/edit
  def edit
    @user = current_user
  end

  # POST /calendars
  # POST /calendars.json
  def create
    @user = current_user
    @calendar = @user.calendars.new(calendar_params)

    respond_to do |format|
      if @calendar.save
        format.html { redirect_to user_calendar_path(@user,@calendar), notice: 'Calendar was successfully created.' }
        format.json { render :show, status: :created, location: @calendar }
      else
        format.html { render :new }
        format.json { render json: @calendar.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /calendars/1
  # PATCH/PUT /calendars/1.json
  def update
    @user = current_user
    @calendar = Calendar.find(params[:id])
    respond_to do |format|
      if @calendar.update(calendar_params)
        format.html { redirect_to user_calendar_path(@user,@calendar), notice: 'Calendar was successfully updated.' }
        format.json { render :show, status: :ok, location: @calendar }
      else
        format.html { render :edit }
        format.json { render json: @calendar.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /calendars/1
  # DELETE /calendars/1.json
  def destroy
    @user = current_user
    @calendar.destroy
    respond_to do |format|
      format.html { redirect_to user_calendars_url, notice: 'Calendar was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_calendar
      @calendar = Calendar.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def calendar_params
      params.require(:calendar).permit(:name)
    end
end

我的基本 CRUD 操作有效：user 登录后，他可以 create、show、edit 和 destroy calendar属于他的。

我现在想弄清楚的是，当 user 创建新 calendar.

我正在考虑将以下代码行添加到 Calendars#Create:

current_user.add_calendar_and_role(@calendar.id, 'Owner')

但我不确定这是一个好的做法。

相反，我不应该在我的 administration 模型中定义一个 make_owner 方法并在 Calendars#Create 操作中将其与回调一起使用吗？

我是否也应该在我的 calendar 模型中实施 accepts_nested_attributes_for？

或者是否有我忘记的更好的解决方案？

Answer 1

总的来说 - 尽可能将代码移至模型。让您的控制器保持简单。

我认为您不需要接受嵌套属性。当我的模型是真正的子对象时，我倾向于使用它，而不仅仅是连接。

你的数据模型看起来不错 - 我想无论你选择什么，你都可以在以后改进它或处理更多的特殊情况。也就是说，我做这种事

class Administration < ActiveRecord::Base

  before_validation :set_default_role

  def set_default_role
    existing_owner = where(:calendar_id => calendar_id, :role => :owner).exists?
    if existing_owner?
      self.role ||= :standard
    else
      self.role ||= :owner
    end
  end

end

Rails 4 has_many :through relationship: 将默认值分配给从父模型创建操作时加入模型属性

Rails 4 has_many :through relationship: assign default value to join model attribute on create action from parent model

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ruby-on-rails-4