已编辑... ActionView::Template::Error (没有路由匹配...缺少必需的键：[:comment_id])

Question

当我访问 photos/show.html.erb 视图时，我从 Heroku 日志中收到以下错误：

ActionView::Template::Error（没有路由匹配 {:action=>"index", :comment_id=>nil, :controller=>"cflags", :photo_id=>"100"} 缺少必需的键：[ :comment_id])

我有非常基本的 Photo 和 Comment 模型可以正常工作，然后我构建了一个用于标记 cmets 的 Cflag 模型。我使用@photo.comments 列出photos/show.html.erb 视图中的cmets。

显示：

# photos/show.html.erb

<% @photo.comments.each do |comment| %>
  <%= form_for(comment, url: photo_comment_cflags_path(@photo, comment)) do |f| %>
    <%= f.hidden_field :user_id, value: current_user.id %>
    <%= f.submit "Report Inappropiate" %>
  <% end %>
<% end %> 

Cflags 控制器：

class CflagsController < ApplicationController
before_action :logged_in_user

def new
end

def create
  @comment = Comment.find(params[:comment_id])
  @cflag = @comment.cflags.build(cflag_params)
    if @cflag.save
      if @comment.cflags_count > 1
        @comment.update_attribute(:approved, false)  
        flash[:success] = "Flag created! Comment ##{@comment.id} has been removed for review. Thank you for your feedback"
        redirect_to :back
      else    
        flash[:success] = "Flag created! Thank you for your feedback"
        redirect_to :back
      end
    else
      redirect_to :back, notice: @cflag.errors.full_messages  
    end    
  end    

  private 
    def cflag_params
      params.require(:cflag).permit(:user_id, :comment_id).merge(user_id: current_user.id)
    end
end

路线：

resources :photos do
  resources :comments, only: [:create, :edit, :destroy] do
    resources :cflags, only: :create
  end  
end

铁路路线：

    photo_comment_cflags GET        /photos/:photo_id/comments/:comment_id/cflags(.:format)          cflags#index
                         POST       /photos/:photo_id/comments/:comment_id/cflags(.:format)          cflags#create
 new_photo_comment_cflag GET        /photos/:photo_id/comments/:comment_id/cflags/new(.:format)      cflags#new
edit_photo_comment_cflag GET        /photos/:photo_id/comments/:comment_id/cflags/:id/edit(.:format) cflags#edit
     photo_comment_cflag GET        /photos/:photo_id/comments/:comment_id/cflags/:id(.:format)      cflags#show
                         PATCH      /photos/:photo_id/comments/:comment_id/cflags/:id(.:format)      cflags#update
                         PUT        /photos/:photo_id/comments/:comment_id/cflags/:id(.:format)      cflags#update
                         DELETE     /photos/:photo_id/comments/:comment_id/cflags/:id(.:format)      cflags#destroy

照片控制器：

def show
  @photo = Photo.approved.find(params[:id])
end

评论控制器：

def create
   @photo = Photo.find(params[:photo_id])
   @comment = @photo.comments.build(comment_params)
   @comment.save
   respond_to do |format|
     format.html { redirect_to :back }
     format.js 
   end 
end   

Cflag 模型：

class Cflag < ActiveRecord::Base
  belongs_to :comment, counter_cache: true
  belongs_to :user, counter_cache: true
  validates :user_id, presence: true 
  validates :comment_id, presence: true
  validates :user_id, uniqueness: { 
    scope: [:comment_id],
    message: 'You can only flag a comment once. Thank you for your feedback.'
  }
  default_scope -> { order(created_at: :desc) }
end

架构：

create_table "cflags", force: :cascade do |t|
  t.integer  "comment_id"
  t.integer  "user_id"
  t.datetime "created_at", null: false
  t.datetime "updated_at", null: false
end

add_index "cflags", ["comment_id"], name: "index_cflags_on_comment_id"
add_index "cflags", ["user_id"], name: "index_cflags_on_user_id"

在 Heroku 控制台中

p = Photo.find(100) 
p.comments = => #<ActiveRecord::Associations::CollectionProxy [#<Comment id: 309, content: "hi", photo_id: 100, user_id: 1, created_at: "2016-07-24 04:43:17", updated_at: "2016-07-24 04:43:17", approved: true, cflags_count: nil>

Answer 1

将表单操作更改为此， 更新：

<% if @photo.comments.any? %>
   <% @photo.comments.each do |comment| %>     
     # you do not have to use comment in form_for, because this form is for creating cflag
     <%= form_for(:cflag, url: photo_comment_cflags_path(@photo, comment), method: "post") do |f| %> 
          <%= f.hidden_field :user_id, value: current_user.id %> 
          <%= f.submit "Report Inappropiate" %> 
     <% end %> 
   <% end %> 
<% end %>

Answer 2

根据Rails documentation，form_for 方法的预期参数是(record, options = {}, &block)。

form_for(record, options = {}, &block) public

创建一个允许用户创建或更新属性的表单 特定模型对象。

该方法可以以几种略有不同的方式使用，具体取决于 你希望在多大程度上依赖 Rails 自动推断 建模应该如何构建表单。对于通用模型对象， 可以通过传递form_for 字符串或符号来创建表单 表示我们关心的对象：

因此，您可能希望删除在form_for 方法中插入的额外[]，它应该如下所示：

<% @photo.comments.each do |comment| %>
  <%= form_for(Cflag.new, url: photo_comment_cflags_path(@photo, comment)) do |f| %>
    <%= f.hidden_field :user_id, value: current_user.id %>
    <%= f.submit "Report Inappropiate" %>
  <% end %>
<% end %> 

我建议你试试这样，看看它是否能解决你当前的问题。

Answer 3

你的第一个参数是数组，试试这个：

<%= form_for(comment, url: photo_comment_cflags_path(@photo, comment)) do |f| %>