Rails中post_delete_path发送GET而非DELETE请求的问题及解决

关联评论与帖子后，调用删除接口时发送了GET请求而非DELETE请求，报错：No route matches [DELETE] "/delete_post.3"。

相关代码 #

路由文件（routes.erb） #

Rails.application.routes.draw do
  #get 'posts/index'
  resources :posts do
    resources :comments, only: [:destroy, :create]
  end

  delete'/delete_post', to: 'posts#destroy'

  resources :likes, only: [:destroy, :create]

  resources :sessions, only: [:create, :destroy]
  get 'sessions/new'
  get 'sing_in', to: 'sessions#new'
  get 'sign_out', to: 'sessions#destroy'

  resources :users, only: [:create, :destroy]
  get 'users/new'
  get '/register', to: 'users#new'

  root 'posts#index'
end

Posts控制器 #

class PostsController < ApplicationController

  before_action :ensure_user
  before_action :correct_user, only: [:edit, :update, :destroy]

  def index
    @posts = Post.all.order("created_at DESC")
  end

  def show
    @post = Post.find(params[:id])
  end


  def new
    @post = current_user.posts.new
  end


  def create
    @post = current_user.posts.new(post_params)

    if @post.save
      redirect_to post_url(@post)
    else
      render 'new', notice: "Couldn't create the post!"
    end

  end

  def edit
    @post = set_post
  end

  def update
    @post = current_user.posts.find(params[:id])

    if @post.update(post_params)
      redirect_to post_url(@post)
    else
      redirect_to post_url(@post), notice: "Couldn't update the post!"
    end
  end


  def destroy
    @post = current_user.posts.find([params[:id]])

    if @post.destroy
      redirect_to posts_path, notice: "Post has been deleted!"
    else
      redirect_to post_url(@post), notice: "Couldn't delete the post!"
    end
  end


  private

  def correct_user
    @post = current_user.posts.find_by(id: params[:id])
    redirect_to root_path, notice: "You are not authorized to edit this post!" if @post.nil?
  end

  def set_post
    return Post.find(params[:id])
  end

  def post_params
    params.require(:post).permit(:title, :content)
  end


end

视图中的删除按钮（帖子详情页） #

<%= button_to 'Delete', delete_post_path(@post), method: :delete %>

注：已尝试将删除路径定义在posts资源下、切换button_to与link_to，均无效果，指定DELETE路由后仍无法匹配。

最终解决方案 #

经排查，问题根源有两点：

1. 路由定义冗余且错误：已经通过resources :posts生成了标准的RESTful路由，额外自定义的delete'/delete_post'路由不符合规范，导致路径匹配异常。需移除该自定义路由，改用RESTful标准的post_path(@post)配合method: :delete生成正确的删除请求路径。

2. 关联数据外键约束冲突：删除带有评论或点赞的帖子时，由于comments和likes表的post_id字段设置为非空，直接删除帖子会触发NotNullViolation错误。需在destroy方法中先清除关联的点赞和评论，再删除帖子。修正后的destroy方法如下：

def destroy
  @post = current_user.posts.find(params[:id])

  @post.likes.destroy_all
  @post.comments.destroy_all

  if @post.destroy
    redirect_to posts_path, notice: "Post has been successfully deleted!"
  else
    redirect_to @post
    flash[:notice] = "Can't delete the post!"
  end
end

内容的提问来源于stack exchange，提问作者Tomax47