如何在不使用任何寶石或插件的情況下創建當前用戶方法？

Question

我知道這是一個愚蠢的，但我想知道我們如何創建一個current_user方法來訪問整個應用程序，而無需使用任何寶石或插件？爲了測試我創建了一個應用程序，使用戶能夠共享文件和folders.How創造這樣的方法，一個用戶只能訪問自己的文件夾和文件，這是我的代碼示例：

登錄控制器：

class LoginController < ApplicationController 
layout 'signup' 
    #to skip checking the authentication and authorization. 
    skip_before_filter :check_authentication, :check_authorization 

    def index 
    end 

    def authenticate 
     if request.post? 
      user = User.authenticate(params[:username],params[:password]) 
      if user 
     session[:current_user_id]=user.id 
     session[:name]= user.first_name 
       puts "session name #{session[:name]}" 
       redirect_to(:subdomain => user.company.subdomain, :controller => :dashboard) 
     else 
     flash.now[:notice] = "Invalid user/password combination" 
     end 

     end 
    end 

    def destroy 
    session[:current_user_id] = nil 
    reset_session 
    flash[:notice] = "You have been successfully logged out." 
    redirect_to root_url 
    end 

end 

用戶模式：

require 'digest/sha1' 



class User < ActiveRecord::Base 

    #sharering method start 
     after_create :check_and_assign_shared_ids_to_shared_folders 
     #this is to make sure the new user ,of which the email addresses already used to share folders by others, to have access to those folders 
     def check_and_assign_shared_ids_to_shared_folders  
     #First checking if the new user's email exists in any of ShareFolder records 
     shared_folders_with_same_email = SharedFolder.find_all_by_shared_email(self.email) 

     if shared_folders_with_same_email   
     #loop and update the shared user id with this new user id 
      shared_folders_with_same_email.each do |shared_folder| 
      shared_folder.shared_user_id = self.id 
      shared_folder.save 
      end 
     end  
     end 

     #to check if a user has acess to this specific folder 
     def has_share_access?(folder) 
      #has share access if the folder is one of one of his own 
      return true if self.folders.include?(folder) 

      #has share access if the folder is one of the shared_folders_by_others 
      return true if self.shared_folders_by_others.include?(folder) 

      #for checking sub folders under one of the being_shared_folders 
      return_value = false 

     folder.ancestors.each do |ancestor_folder| 

      return_value = self.being_shared_folders.include?(ancestor_folder) 
      if return_value #if it's true 
       return true 
      end 
      end 

      return false 
     end 
    #sharing method end 

     def self.authenticate(name, password) 
     user = self.find_by_username(name) 

     if user 
      expected_password = encrypt_password(password, user.salt) 
      if user.hashed_password != expected_password 
      user = nil 
      end 
     end 
     user 
     end 

     #'password' is a virtual attribute 
     def password 
     @password 
     end 

     def password= (pwd) 
     @password =pwd 
     return if pwd.blank? 
     create_new_salt 
     self.hashed_password = User.encrypt_password(self.password, self.salt) 
     end 

     def self.users_in_company(user_id) 
      User.find(user_id).company.users 
     end 

    private 
     def password_non_blank 
     errors.add(:password, "Missing password, please enter your password") if hashed_password.blank? 
     end 

     def create_new_salt 
     self.salt = self.object_id.to_s + rand.to_s 
     end 

     def self.encrypt_password(password, salt) 
     string_to_hash = password +"prftnxt" + salt 
     Digest::SHA1.hexdigest(string_to_hash) 
     end 

    end 

我要訪問的所有文件，「current_user.files」是有可能沒有任何寶石？

應用助手：

module ApplicationHelper 
#for current user to use through out the app 
    def current_user 
    @current_user ||= session[:current_user_id] && User.find_by_id(session[:current_user_id]) # Use find_by_id to get nil instead of an error if user doesn't exist 
    end 

end 

應用控制器：

class ApplicationController < ActionController::Base 
     include UrlHelper 
     #include ApplicationHelper 
     helper_method :current_user #make this method available in views 
     protect_from_forgery 


# def current_user 
# @current_user ||= session[:current_user_id] && User.find_by_id(session[:current_user_id]) # Use find_by_id to get nil instead of an error if user doesn't exist 
# end 



end 

和任務控制器：

class TasksController < ApplicationController 


    # GET /tasks 
    # GET /tasks.xml 
    def index 
    @menu = "Timesheet" 
    @page_name = "Manage Task" 
    company_id = Company.find_by_subdomain(request.subdomain) 
    @users = User.find_all_by_company_id(company_id) 
    @tasks = current_user.tasks.all#Task.all 
    @task = Task.new 

    respond_to do |format| 
     format.html # index.html.erb 
     format.html # new.html.erb 
     format.xml { render :xml => @tasks } 
    end 
    end 
end 

和我的錯誤信息，我得到：

NameError in TasksController#index 

undefined local variable or method `current_user' for #<TasksController:0xfa7e638> 

Answer 1

喜的朋友，而無需使用任何寶石或插件：

在我application_helper.rb我做這樣的：

module ApplicationHelper 
    def current_user 
    User.find(session[:current_user_id]) 
    end 
end 

，並在我的application controller.rb末我打電話這一點，因爲在這裏，我可以通過應用程序訪問它：

class ApplicationController < ActionController::Base 
    include UrlHelper 
    include ApplicationHelper 
    helper_method :current_user 
end 

，現在我可以訪問與current user任何數據：

，如：

@tasks = current_user.tasks

感謝我所有的朋友提出寶貴的答案。

Answer 2

這並不難;）只是定義你所需要的方法：我已經找到了方法來創建current_user方法

class ApplicationController < ... 
    def current_user 
    @current_user ||= session[:current_user_id] && User.find_by_id(session[:current_user_id]) # Use find_by_id to get nil instead of an error if user doesn't exist 
    end 
    helper_method :current_user #make this method available in views 
end