Question

我正在尝试使用scaffold在我之前创建的博客中创建一个新的操作列表。

我收到错误

找不到带有'id'=
的博客

on controllers / blogs_controller.rb

这是我的控制器代码。

class BlogsController < ApplicationController
before_action :authenticate_user!, :except => [:index, :show]
layout 'admin', only:[:new, :create, :update, :destroy, :edit, :list]
before_action :set_blog, only: [:show, :edit, :update, :destroy, 
:list]

# GET /blogs
# GET /blogs.json
def index
 @blogs = Blog.all
end

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

def list
 @blogs = Blog.all
end

# GET /blogs/new
def new
 @blog = Blog.new
end

# GET /blogs/1/edit
def edit
end

# POST /blogs
# POST /blogs.json
def create
 @blog = Blog.new(blog_params)

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

# PATCH/PUT /blogs/1
# PATCH/PUT /blogs/1.json
def update
 respond_to do |format|
  if @blog.update(blog_params)
    format.html { redirect_to @blog, notice: 'Blog was successfully updated.' }
    format.json { render :show, status: :ok, location: @blog }
  else
    format.html { render :edit }
    format.json { render json: @blog.errors, status: :unprocessable_entity }
  end
end
end

# DELETE /blogs/1
# DELETE /blogs/1.json
def destroy
@blog.destroy
respond_to do |format|
  format.html { redirect_to blogs_url, notice: 'Blog was successfully destroyed.' }
  format.json { head :no_content }
end
end

private
 # Use callbacks to share common setup or constraints between actions.
 def set_blog
  @blog = Blog.find(params[:id])
 end

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

端

和我的routes.rb是

Rails.application.routes.draw do

resources :blogs do
 collection do
    get :list, :as => 'list'
 end
end
 root to: 'home#index'
end

现在，在名为list.html.erb的新控制器视图中，我需要查看除正常show动作之外的所有博客文章。

在我的list.html.erb

中

<td><%= link_to blog.title %></td>

错误显示在set_blog

中

private
 # Use callbacks to share common setup or constraints between actions.
 def set_blog
   @blog = Blog.find(params[:id])
 end

Answer 1

通过在:list行动之前加入set_blog方法，你强迫它使用id作为参数查找特定的博客，但你想要的实际上是你在list方法中的内容，这是所有博客。

所以这个

 def set_blog
  @blog = Blog.find(params[:id])
 end

正在覆盖此

def list
  @blogs = Blog.all
end

要修改此

before_action :set_blog, only: [:show, :edit, :update, :destroy, :list]

通过在操作

之前从设置博客中删除:list方法来实现此目的

before_action :set_blog, only: [:show, :edit, :update, :destroy]

Answer 2

删除

：列表

来自before_action的

：set_blog

在rails中创建脚手架创建的控制器的新操作时出错

2 个答案: