Ruby on rails 3 如何在不使用任何gem或插件的情况下创建当前用户方法？

我知道这很愚蠢，但我想知道我们如何创建一个当前用户方法，在不使用任何gem或插件的情况下访问整个应用程序？为了测试它，我创建了一个应用程序，使用户能够共享文件和文件夹。如何创建这样的方法，用户只能访问他的文件夹和文件？以下是我的代码示例：

登录控制器：

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 

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

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

应用程序控制器：

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 

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

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

class ApplicationController

在任务控制器中：

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 

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

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

class TasksController@tasks}
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我收到的错误信息是：

NameError in TasksController#index

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

TasksController#索引中的

name错误
未定义的局部变量或方法“当前用户”#

这并不难；）只需定义所需的方法：

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

类应用程序控制器<。。。
def当前用户
@当前用户| |=会话[：当前用户| id]&&user.find_by_id（会话[：当前用户_id]）#如果用户不存在，则使用find_by_id获取nil而不是错误
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helper_method：当前_用户#使此方法在视图中可用
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嗨，朋友们，我找到了不使用任何gem或插件创建

当前用户

方法的方法：

在我的

应用程序\u helper.rb

中，我执行了以下操作：

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

最后，在我的

应用程序控制器.rb中，我调用了这个，因为我可以从这里通过应用程序访问它：

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

class ApplicationController

现在我可以访问与当前用户相关的任何数据：

比如：

@tasks=当前用户。tasks

感谢我所有的朋友提供了宝贵的答案。
Hi Marian正在使用您的代码并在我的任务控制器中以“@tasks=current_user.tasks”的形式应用该方法，然后它会抛出一个错误“undefined method‘tasks’”，我遗漏了什么吗？嗨，Marian，这是我的错误消息：TasksController中的NameError#索引未定义的局部变量或方法“current_user”for#您需要（应用程序）控制器中的方法，如果您将该方法放入帮助器模块中，它将仅在您的视图中可用！嗨，Marian，我按照你说的做了，但这次出现了“nil:NilClass的未定义方法'tasks'错误”