屬於用戶對象的軌道rotum對象

Question

我有2個控制器用戶和Rota。我希望用戶能夠創建自己的Rota，但只能編輯，顯示和銷燬自己的Rota。我需要能夠編寫代碼，以便我的rotum對象屬於用戶對象。

ROTA控制器：

class RotaController < ApplicationController 
    respond_to :html, :xml, :json 
    before_action :set_rotum, only: [:show, :edit, :update, :destroy] 
    def edit 
    @rotum = @user.rota.find params[:id] 
    end 
    def index 
    @rota = Rotum.all 
    respond_with(@rota) 
    end 

    def show 
    respond_with(@rotum) 
    end 

    def new 
    @rotum = Rotum.new 
    respond_with(@rotum) 
    end 

    def edit 
    end 

    def create 
    @rotum = Rotum.new(rotum_params) 
    @rotum.save 
    respond_with(@rotum) 
    end 

    def update 
    @rotum.update(rotum_params) 
    respond_with(@rotum) 
    end 

    def destroy 
    @rotum.destroy 
    respond_with(@rotum) 
    end 

    private 

    def set_rotum 
    @rotum = current_user.rotums.find(params[:id]) 
    if @rotum.nil? 
     render :html => "Not authorized", :status => 401 
    end 
    end 

    def rotum_params 
    params.require(:rotum).permit(:name, :email, :mobile, :category) 
    end 
end 

用戶控制器

class UsersController < ApplicationController 
    before_filter :authenticate_user! 
    after_action :verify_authorized 

    def index 
    @users = User.all 
    authorize User 
    end 

    def show 
    @user = User.find(params[:id]) 
    authorize @user 
    end 

    def update 
    @user = User.find(params[:id]) 
    authorize @user 
    if @user.update_attributes(secure_params) 
     redirect_to users_path, :notice => "User updated." 
    else 
     redirect_to users_path, :alert => "Unable to update user." 
    end 
    end 

    def destroy 
    user = User.find(params[:id]) 
    authorize user 
    user.destroy 
    redirect_to users_path, :notice => "User deleted." 
    end 


    def edit 
    @rotum = @user.rota.find params[:id] 
    end 

    private 

    def secure_params 
    params.require(:user).permit(:role) 
    end 
end 

到目前爲止，我的羅塔允許任何人創建，顯示，編輯和刪除的ROTAS頁面上的羅塔。我只希望用戶能夠編輯他們創建的只有他們自己的rota。爲此，我被告知告訴rota對象屬於用戶對象。我如何在我的控制器或模型中執行此操作。

用戶模型

class User < ActiveRecord::Base 
has_many :rota, dependent: :destroy 

    enum role: [:user, :vip, :admin] 
    after_initialize :set_default_role, :if => :new_record? 

    def set_default_role 
    self.role ||= :user 
    end 

    # Include default devise modules. Others available are: 
    # :confirmable, :lockable, :timeoutable and :omniauthable 
    devise :database_authenticatable, :registerable, 
    :recoverable, :rememberable, :trackable, :validatable 
end 

ROTUM模型

class Rotum < ActiveRecord::Base 
    belongs_to :user 
end 

我得到的錯誤：在/羅塔

NoMethodError/15

未定義的方法`rotums'爲＃

Answer 1

你沒有顯示你的模型，所以我假設你有一個has_many關係

class User < ActiveRecord::Base 
    has_many :rota, dependent: :destroy 
end 

class Rotum < ActiveRecord::Base 
    belongs_to :user 
end 

然後在你的控制器，你可以使用以下命令：

class UsersController < ApplicationController 
    .... 
    def edit 
    @rotum = @user.rota.find params[:id] 
    end 

注意，這將引發一個ActiveRecord::RecordNotFound例外，如果用戶正在試圖編輯不屬於他的旋律。

可避免這樣的問題有以下：

class UsersController < ApplicationController 
    .... 
    def edit 
    @rotum = @user.rota.find_by id: params[:id] # returns nil in case the record does not exist or does not belong to @user 
    redirect_to "somewhere", alert: 'You cannot edit this element' if @rotum.blank? 
    end