'comments_path' 中使用“Commentable”form_for 多态关联的未定义方法

Question

我收到“未定义方法 'cmets_path' for...”的错误 在 app/views/cmets/_form.html.erb 中的这段代码（第 1 行）。

我最近尝试在我正在构建的网站上通过多态关联来实现可嵌套的 cmets；但是，我遇到了一个不允许我前进的问题。

我正在尝试在“可评论”模型（即本例中的博客）上实现嵌套 cmets，然后当单击 show 时，会显示所有嵌套 cmets，并且个人可以在博客上发表评论或回复在不离开页面的情况下评论（并因此导致嵌套的 cmets）。

我已经包含了一些其他文件来显示设置，但如果我错过了一个必要的文件，请告诉我，我会及时添加它。任何帮助深表感谢。我已经被难住了几个小时，我相信这很简单。

<%= form_for [@commentable, @comment] do |f| %>
  <%= f.hidden_field :parent_id %></br>
    <%= f.label :content, "New Comment" %></br>
    <%= f.text_area :body, :rows => 4 %></br>
    <%= f.submit "Submit Comment" %>
<% end %>

app/views/blogs/show.html.erb

<div class="content">
  <div class="large-9 columns" role="content">
    <h2>Comments</h2>
    <div id="comments">
      <%= nested_comments @comments %>
      <%= render "comments/form" %>
    </div>
  </div>
</div>

app/controllers/cmets_controller

class CommentsController < ApplicationController
      def new
        @parent_id = params.delete(:parent_id)
        @commentable = find_commentable
        @comment = Comment.new( :parent_id => @parent_id, 
                                :commentable_id => @commentable.id,
                                :commentable_type => @commentable.class.to_s)
      end

      def create
        @commentable = find_commentable
        @comment = @commentable.comments.build(params[:comment])
        if @comment.save
          flash[:notice] = "Successfully created comment."
          redirect_to @commentable
        else
          flash[:error] = "Error adding comment."
        end
      end



      private
      def find_commentable
        params.each do |name, value|
          if name =~ /(.+)_id$/
            return $1.classify.constantize.find(value)
          end
        end
        nil
      end

      def comment_params
        params.require(:comment).permit(:parent_id, :body, :commentable_type, :commentable_id)
      end
    end

app/controller/blogs_controller.rb

class BlogsController < ApplicationController
  before_filter :authenticate, :except => [ :index, :show ]
  before_action :set_blog, only: [:show, :edit, :update, :destroy]
  include MyModules::Commentable

  # GET /blogs
  # GET /blogs.json
  def index
    @blogs = Blog.all.order('created_at DESC')

    respond_to do |format|
      format.html 
      format.json
      format.atom
    end
  end

  # GET /blogs/1
  # GET /blogs/1.json
  def show
    @blog = Blog.find(params[:id])
  end

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

  # GET /blogs/1/edit
  def edit
    @blog = Blog.find(params[:id])
  end

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

    respond_to do |format|
      if @blog.save
        flash[:success] = "Blog was sucessfuly created"
        format.html { redirect_to @blog }
        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)
        flash[:success] = "Blog was successfully updated."
        format.html { redirect_to @blog }
        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|
      flash[:success] = "Blog was successfully deleted."
      format.html { redirect_to blogs_url }
      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, :body, :image, :image_cache, :remote_image_url)
    end

  private
  def authenticate
    authenticate_or_request_with_http_basic do |name, password|
      name == "admin" && password == "runfast"
    end
  end
end

我的路由文件看起来像这样...

Rails.application.routes.draw do
  resources :blogs do
    resources :comments
  end

  resources :applications

  resources :reviews

  resources :properties

  root to: 'blogs#index'
end

博客和评论模型...

class Blog < ActiveRecord::Base
  validates_presence_of :body, :title
  has_many :comments, :as => :commentable, :dependent => :destroy
  mount_uploader :image, ImageUploader
end

class Comment < ActiveRecord::Base
  has_ancestry
  belongs_to :commentable, :polymorphic => true
  validates_presence_of :body
end

最后是 lib/my_modules/commentable.rb 中的可注释模块

require 'active_support/concern'

module MyModules::Commentable
    extend ActiveSupport::Concern

    included do 
      before_filter :comments, :only => [:show]
    end

    def comments
      @Commentable = find_commentable
      @comments = @Commentable.comments.arrange(:order => :created_at)
      @comment = Comment.new
    end

    private

    def find_commentable
      return params[:controller].singularize.classify.constantize.find(params[:id])
    end

  end

@博客

#<Blog id: 8, title: "New Blog Post about Databases.... Again", body: "RDM, the database management system, was designed ...", created_at: "2015-03-01 22:28:07", updated_at: "2015-03-03 00:11:07", image: "IMG_2210.JPG">

@commentable

#<Blog id: 8, title: "New Blog Post about Databases.... Again", body: "RDM, the database management system, was designed ...", created_at: "2015-03-01 22:28:07", updated_at: "2015-03-03 00:11:07", image: "IMG_2210.JPG">

app/helpers/cmets_helper.rb

module CommentsHelper
  def nested_comments(comments)
    comments.map do |comment, sub_comments|
      content_tag(:div, render(comment), :class => "media")
    end.join.html_safe
  end
end

@_params 实例变量更好的错误

{"utf8"=>"✓", "authenticity_token"=>"OH2tDdI5Kp54hf5J78wXHe//Zsu+0jyeXuG27v1REqjdAec7yBdlrVPLTZKEbLZxgR2L7rGwUwz5BlGTnPcLWg==", "comment"=>{"parent_id"=>"", "body"=>"Hello!\r\n"}, "commit"=>"Submit Comment", "controller"=>"comments", "action"=>"create", "blog_id"=>"8"}

Answer 1

您在此视图中遇到错误：app/views/blogs/show.html.erb。

此视图的数据已在blogs#show 中准备好。所以在你看来，你应该有<%= form_for [@blog, @comment] do |f| %>，因为你设置了@blog，而不是@commentable。

您也应该使用@comment = Comment.new。不知道你把这个放在哪里...

在您的视图中执行<% raise @commentable.inspect %> (app/views/blogs/show.html.erb)。如果它是 nil，那么这就是你收到错误的原因。