ruby-on-rails - before_filter:authenticate_user !，除了:[:index]/Rails 4

Question

我有一个Listings Controller(Devise用户系统)，在 Rails 3 中，我刚刚使用过

before_filter :authenticate_user!, except: [:index]

在查看特定列表之前检查用户是否已登录。

我的主页(索引)在底部显示一个列表，用户可以看到它们，但是，一旦他单击一个 View 以查看它，他就会被重定向到登录页面。

这就是为什么我在 Controller 中没有

Listing.new -> current_user.listings.new

在 Rails 4 中，事情似乎已经改变，我找不到正确的方法来做。

我搜索了一下，发现命令已更改为

before_action :authenticate_user!, :except => [:index]

访客现在可以查看索引，但是如果他单击列表，则不会重定向到登录页面，而是出现此错误。

NoMethodError in ListingsController#show
undefined method `listings' for nil:NilClass

# Use callbacks to share common setup or constraints between actions.
def set_listing
        @listing = current_user.listings.find(params[:id])
end

# Never trust parameters from the scary internet, only allow the white list through.

我的列表 Controller

class ListingsController < ApplicationController
  before_action :set_listing, only: [:show, :edit, :update, :destroy]
    before_action :authenticate_user!, :except => [:index]

  # GET /listings
  # GET /listings.json
  def index
    @listings = Listing.order("created_at desc")
  end

  # GET /listings/1
  # GET /listings/1.json
  def show
  end

  # GET /listings/new
  def new
        @listing = current_user.listings.build
  end

  # GET /listings/1/edit
  def edit
  end

  # POST /listings
  # POST /listings.json
  def create
        @listing = current_user.listings.build(listing_params)

    respond_to do |format|
      if @listing.save
        format.html { redirect_to @listing, notice: 'Listing was successfully created.' }
        format.json { render action: 'show', status: :created, location: @listing }
      else
        format.html { render action: 'new' }
        format.json { render json: @listing.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /listings/1
  # PATCH/PUT /listings/1.json
  def update
    respond_to do |format|
      if @listing.update(listing_params)
        format.html { redirect_to @listing, notice: 'Listing was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @listing.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /listings/1
  # DELETE /listings/1.json
  def destroy
    @listing.destroy
    respond_to do |format|
      format.html { redirect_to listings_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_listing
            @listing = current_user.listings.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def listing_params
      params.require(:listing).permit(:title, :description, :image)
    end
end

EDIT: PROBLEM 2

如果另一个“登录用户”尝试查看另一个用户在获取此信息时创建的列表->

和日志

Answer 1

尝试此操作，这将允许 guest 查看参数中提供的列表:

def set_listing
    unless current_user
        @listing = Listing.find(params[:id])
    else
        @listing = current_user.listings.find(params[:id])
    end
end

更新:

看来您想按参数而不是current_user显示 list 。如果是这样，请如下更新您的set_listing定义:

def set_listing
    @listing = Listing.find(params[:id]) if params[:id]
end