评论中的 ActionController::UrlGenerationError#show

Question

我使用与 cmets 的多态关联。当我尝试在显示模板中添加“编辑”和“销毁”时，标题中出现错误（现在只需编辑）。如何添加两个链接以显示？

cmets_controller.rb

class CommentsController < ApplicationController
  ....
  before_action :signed_in_user, only: [:new, :edit]
  before_filter :load_commentable

def index
  @commentable = load_commentable
  @comments = @commentable.comments
end

def show
end

def edit
  @commentable = load_commentable
end

def new
 @commentable = load_commentable
 @comment = @commentable.comments.new
end

def create
 @comment = @commentable.comments.new(comment_params)
 @comment.user = current_user

if @comment.save
  redirect_to @comment, notice: "Created."
 else
  render :new
 end
end

def update
  @comment = @commentable.comments.build(comment_params)
  @comment.user = current_user

respond_to do |format|
  if @comment.update(comment_params)
    format.html { redirect_to @comment, notice: 'It was successfully updated.' }
    format.json { head :no_content }
  else
    format.html { render action: 'edit' }
    format.json { render json: @comment.errors, status: :unprocessable_entity }
  end
 end
end



private

def load_commentable
  resource, id = request.path.split('/')[1, 2]
  @commentable = resource.singularize.classify.constantize.find(id)
end

....

end

show.html.erb 模板

<%= link_to "Edit", [:edit, @commentable, :comment] %>

表格

<%= form_for [@commentable, @comment] do |f| %>
....

full trace

日志

由 CommentsController 处理#显示为 HTML
参数：{"post_id"=>"1", "id"=>"2"}
评论加载 (0.3ms) SELECT "cmets".* FROM "cmets" WHERE "cmets"."id" = ?限制 1 [["id", "2"]]
Post Load (0.2ms) SELECT "posts".* FROM "posts" WHERE "posts"."id" = ?限制 1 [["id", "1"]]
用户负载 (0.2ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT 1 [["id", 2]]
(0.2ms) SELECT COUNT(*) FROM "cmets" WHERE "cmets"."user_id" = ? [["user_id", 2]] CACHE (0.0ms) SELECT COUNT(*) FROM "cmets" 在哪里“cmets”。“user_id”=？ [["user_id", 2]]
在布局/应用程序中渲染 cmets/show.html.erb (10.7ms)
在 19 毫秒内完成 500 内部服务器错误

ActionView::Template::Error (没有路由匹配 {:action=>"edit", :controller=>"cmets", :post_id=>#, :id=>nil, :format=>nil} 缺少必需的键：[:id])：

25:           <div class="thumbsdown"><%= link_to image_tag('othericons/thumbiconDown.PNG', height: '20', width: '20'),

“#”%>
26:
27：
28: 29:
30：

31：app/views/cmets/show.html.erb:28:in `_app_views_cmets_show_html_erb___2937579164590753686_69833853514120'

Rendered /home/action/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_trace.erb

(1.6ms) 渲染 /home/action/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.2ms) 渲染 /home/action/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/template_error.erb 在救援/布局内 (19.1ms)

路线：

resources :posts do
  resources :comments
end

Answer 1

更改Edit链接如下：

<%= link_to "Edit", edit_post_comment_path(@commentable, @comment) %> 

您已将 Post 和 Comment 设置为嵌套路由，因此您需要将 Post 和 Comment 的对象传递给编辑路径。

编辑

对于多态关联，可以如下使用：

<%= link_to "Edit", [:edit, @commentable, @comment] %>