具有嵌套资源的 Rails 表单正在生成 nil 输出

Question

我正在创建一个用于向建议框添加建议的表单。但是，虽然我能够成功提交表单，并且 rails 返回一条提示已成功提交建议的 flash 消息，但建议消息的值为 nil。

我已经查看了有关具有嵌套资源的表单的其他各种帖子，但没有任何帮助帮助我解决问题。

这就是我正在做的：

1.转到 localhost:3000/suggestion_boxes/1/suggestions/new

2。显示 app/views/suggestions/new.html.haml 表单：

%header
  %h1.title
    = @suggestion_box.name + " Suggestion Box"
.main
  = form_for ([@suggestion_box, @suggestion_box.suggestions.build]) do |f|
    - if @suggestion.errors.any?
      #error_explanation
        %ul
          - @suggestion.errors.messages.values.each do |msg|
            = msg.to_sentence
    .field
      %br/
      = f.text_area :suggestion_message, type:"text", placeholder:"Drop a note in our suggestion box...", :rows => 6, :cols => 30
    .actions
      = f.submit "Continue"

3.我在 :suggestion_message 字段中输入文本，然后单击提交。然后显示app/views/suggestion_boxes/show.html.haml：

%header
  %h1.title
    = @suggestion_box.name + " Suggestion Box"
%p#notice= notice
%p
  = link_to "Post a new suggestion", new_suggestion_box_suggestion_path(@suggestion_box)
%table
  %tr
    %th Message
    - @suggestions.each do |suggestion|
      %tr
        %td
          = suggestion.suggestion_message

然而，在此处显示建议已成功提交的快速消息时，suggest_message 表为空白。

这是我在数据库中查询此建议框的建议时得到的结果：

Suggestion Load (1.1ms)  SELECT "suggestions".* FROM "suggestions" WHERE
"suggestions"."suggestion_box_id" = 1 => [#<Suggestion id: 1, suggestion_message: nil, created_at: "2013-06-04 15:49:58", updated_at: "2013-06-04 15:49:58", anonymous_suggestion: nil, member_id: nil, suggestion_box_id: 1>,

#]

关于为什么建议消息是 nil 的任何想法，即使它看起来正在被保存？

非常感谢您的帮助！

可能需要回答这个问题的文件片段。我只包括了我认为相关的部分

建议框模型：

class SuggestionBox < ActiveRecord::Base
  attr_accessible :name , :suggestions_attributes
  belongs_to :organization
  has_many :suggestions, :dependent => :destroy 
  accepts_nested_attributes_for :suggestions
end

建议模型：

class Suggestion < ActiveRecord::Base
  attr_accessible :suggestion_message, :anonymous_suggestion
  belongs_to :suggestion_box
end

routes.rb

SuggestionBoxApp::Application.routes.draw do
  resources :invites, :organizations, :users, :sessions, :password_resets

  resources :suggestion_boxes do
    resources :suggestions
  end
end

建议控制器

class SuggestionsController < ApplicationController

  def new
    @suggestion_box = SuggestionBox.find(params[:suggestion_box_id])
    @suggestion = @suggestion_box.suggestions.build

    flash[:error] = "Sorry, no suggestion box found with the id #{:id}." and return unless @suggestion_box

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @suggestion }
    end
  end

  def create
    @suggestion_box = SuggestionBox.find(params[:suggestion_box_id])
    @suggestion = @suggestion_box.suggestions.new

    respond_to do |format|
      if @suggestion.save
        format.html { redirect_to suggestion_box_path(@suggestion_box), notice: 'Suggestion was successfully submitted.' }
        format.json { render json: @suggestion, status: :created }
      else
        format.html { render action: "new" }
        format.json { render json: @suggestion.errors, status: :unprocessable_entity }
      end
    end
  end
end

建议框控制器

  class SuggestionBoxesController < ApplicationController
    def show
      @suggestion_box = SuggestionBox.find(params[:id])
      @suggestions = @suggestion_box.suggestions.all

      respond_to do |format|
        format.html # show.html.erb
        format.json { render json: @suggestions }
      end
    end
  end

Answer 1

既然只创建建议，为什么要使用嵌套表单？

= form_for @suggestion do |f|

其他一切都应该保持不变并且应该可以工作。

顺便说一句，由于您不使用嵌套属性，因此您的SuggestionBox 模型中既不需要accepts_nested_attributes_for :suggestions，也不需要attr_accessible :suggestions_attributes。