Question

更新了

下面的答案是我的新link_to

<%= link_to "Post a Question", new_classifieds_question_path(@classified) %>

和我的控制器

class QuestionsController < ApplicationController

  def index
  end

  def new
    @classified = Classified.find(params[:classified_id])
    @question = Question.new 
  end 

  def create
    @classified = Classified.find(params[:classified_id])
    @question = Question.new(params[:question])
    @classified.questions << @question
    if @question.save 
      flash[:notice] = "Question has been posted"
    else
      flash[:notice] = "It did not go through"
    end
  end
end

新路线

  resource :classifieds do 
    resources :questions
  end

分类模型

class Classified < ActiveRecord::Base
  has_many :questions
end

和问题模型

class Question < ActiveRecord::Base
  attr_accessible :question_body, :classifieds_id

  belongs_to :classified
end

和我的新错误

Couldn't find Classified without an ID

我有一个带有两个新/创建方法的问题控制器

  def new
    @question = Question.new 
  end 

  def create
    @question = Question.new(params[:question])
    @question.classifieds_id = @classified.id
#@question.classifieds_id = params[:id]
    if @question.save 
      flash[:notice] = "Question has been posted"
    else
      flash[:notice] = "It did not go through"
    end
  end

问题属于分类广告。架构中的问题表具有classifieds_id列。

这是我的问题模型

class Question < ActiveRecord::Base
  attr_accessible :question_body, :classifieds_id

  belongs_to :classified
end

在我的routes.rb

中

resources :questions

以下是我的link_to的一个变体（在我的show.html.erb中）

这是我在另一个控制器中的show方法

  def show
    @classified=Classifieds.find(params[:id])
  end


  <td>
    <%= link_to "Post a Question", new_question_path(@classified) %>
  </td>

我正在尝试传递由问题控制器处理的分类实例的id。

我尝试了很多版本的link_to，就像这样

  <td>
    <%= link_to "Post a Question", new_question_path(:id => @classified.id) %>
  </td>

并且喜欢这个

  <td><%= link_to "Post a Question", {:controller => "questions", :action => "new", :classified_id => @classified.id }, :class => "btn btn-default btn-lg" %></td>
  <tr>

黑客攻击不起作用，在stackoverflow上搜索问题也不起作用。

我试过在show.html.erb

中这样做

  <p>
    <%= @classified.id %>
  </p>

并输出值。我安装了更好的错误并传入nil value。

使用gem 'rails', '3.2.13'

Answer 1

如果你的路线中有嵌套资源......

resources :classifieds do
  resources :questions
end

那会给你方法

<%= link_to "Post a question", new_classifieds_question_path(@classified) %>

您的新方法将收到classified_id

def new
  @classified = Classified.find(params[:classified_id])
  @question = Question.new
end

def create
  @classified = Classified.find(params[:classified_id])
  @question = Question.new(params[:question]
  @classified.questions << @question
   ...
end

EDIT 抱歉，忘记了路径调用中的_path，现已修复。

通过Link_to传递Nil值到控制器值丢失

1 个答案: