Question

我收到了错误

HomeController中的NoMethodError #index未定义方法`id'代表nil：NilClass。

@id = params[:id]
@email = [:email]
if @id == @user.id  && @email == @user.email
  render :text =>   "sucsess"
else
  render :text =>   "fail"

错误消息告诉我这些代码很奇怪。它说undefined method 'id'，@id似乎方法是@id == @user.id吗？（我认为我定义@id是可变的）

我该怎么办才能修复它？

home_controller

class HomeController < ApplicationController
  def index 
    @id = params[:id]
    @email = [:email]
    if @id == @user.id  && @email == @user.email
      render :text =>   "成功"
    else
      render :text =>   "失敗"
    end
  end

  def create
    userData = UserData.new(create_params)
    user = User.find(params[:id]).to_json

    # エラー処理
    unless  userData.save
      @error_message = [memo.errors.full_messages].compact
    end
  end
end

的routes.rb

Rails.application.routes.draw do
  devise_for :users
  root to: "home#index"
  get 'home/index'
  post 'home/index'

  namespace :home, default: {format: :json} do
    resources :index, only: :create
  end
end

Answer 1

HomeController中的NoMethodError #index未定义方法`id'代表nil：NilClass。

索引操作中的@user是nil

您需要先在索引操作或@user

中设置before_filter

解决方案1 

def index
  @id = params[:id]
  @email = [:email]
  @user = User.find(params[:id]) # or current_user whatever your logic is
  if @id == @user.id  && @email == @user.email
    render :text =>   "成功"
  else
    render :text =>   "失敗"
  end
end

解决方案2

为before_filter操作添加index

before_filter :find_user, only: [:index]

private

def find_user
  @user = User.find(params[:id]) # or current_user implement this according to your logic
end

Answer 2

您没有@user的值，这就是为什么它表示未找到的方法id。你必须具备以下价值：

@user = User.find(params[:id])

或

@user = User.first

在你的代码上：

def index
  @user = User.first # defined User here like code on this line I added
  @id = params[:id]
  @email = [:email]
  if @id == @user.id  && @email == @user.email
    render :text =>   "成功"
  else
    render :text =>   "失敗"
  end
end

你应该确保你定义它。如果您有before_filter :your_method_define_user, only: [:index]，请确保:your_method_define_user的值为@user。

正如上面写的@Deepak Mahakale。我想你很困惑。试试完整的代码：

<强>更新：

您的路线：

Rails.application.routes.draw do
  devise_for :users
  get 'home/index' # you must decide what to use post or get. But I use get here as default how index method is implemented in rails.
  root to: "home#index"
end

你的控制器：

class HomeController < ApplicationController
  before_filter :find_user, only: [:index]

  def index 
    @id = params[:id]
    @email = [:email]
    if @id == @user.id  && @email == @user.email
      render :text =>   "成功"
    else
      render :text =>   "失敗"
    end
  end

  def create
    userData = UserData.new(create_params)
    user = User.find(params[:id]).to_json

    # エラー処理
    unless  userData.save
      @error_message = [memo.errors.full_messages].compact
    end
  end



  private

    def find_user
      @user = User.find(params[:id]) # You should specify this code what are your comparing to.
    end
end

如果你使用get请求，你应该在url中传递参数，例如：

localhost:3000/home?id=<your_id>&email=<email_address>

如果帖子将其传递给表单中提供的字段。

NoMethodError未定义的方法

2 个答案: