Rails Ruby 中的嵌套属性未保存

Question

首先我会说我已经查看了以下答案但仍然没有找到有效的解决方案（但是，考虑到我可能忽略了一些东西，我将它们包括在内以供参考）：

Ruby on Rails - Not saving User - Nested Attributes and Nested Forms
Nested Attributes in ruby on rails
Nested attributes not saving in database? Does not display values - Ruby on Rails

问题描述：我有一个带有Cue嵌套表单的表单块。表单正确呈现并且 Block 正确保存，但 Cue 未出现在 Cue table 中，即提交 Block 时 Cue 未保存。我正在使用 Rails 4.2.5.1。我在提交时也没有收到任何错误，这让诊断有点困难。

代码：

_form.html.erb - 块

<%= form_for(@block) do |f| %>
  <% if @block.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@block.errors.count, "error") %> prohibited this block from being saved:</h2>

      <ul>
      <% @block.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field hidden">
    <%= f.label :block_code, class: "hidden" %><br>
    <%= f.text_field :block_code, class: "form-control hidden" %>
  </div>
  <div class="field">
    <%= f.label :block_duration %><br>
    <div class="input-group">
      <%= f.number_field :block_duration, class: 'text_field form-control', :step => 'any' %>
      <div class="input-group-addon">seconds</div>
    </div>
  </div>
  <div class="field">
    <label>Does this block have a cue associated with it?</label>
    <input type="radio" name="cue" value="cueYes" data-type="cueYes" data-radio="cue"> Yes
    <input type="radio" name="cue" value="cueNo" data-type="cueNo" data-radio="cue" checked> No
    <div class="field" id="cueYes">
      <%= f.fields_for :cues do |ff| %>
        <div class="field hidden">
          <%= ff.label :cue_code, class: "hidden" %><br>
          <%= ff.text_field :cue_code, class: "hidden" %>
        </div>
        <div class="field">
          <%= ff.label "Cue Type" %><br>
          <%= ff.collection_select(:cue_type_code, CueType.all, :cue_type_code, :cue_type_name, {prompt: "Select a cue type..."}, {class: "form-control"}) %>
        </div>
        <div class="field">
          <%= ff.label "Cue Description" %><br>
          <%= ff.text_area :cue_description, class: "form-control" %>
        </div>
        <div class="field">
          <%= ff.label "Cue Method" %><br>
          <%= ff.collection_select( :cue_method_code, CueMethod.all, :cue_method_code, :cue_method_name, {prompt: "Select a cue method..."}, {class: "form-control"}) %>
        </div>
      <% end %>
    </div>
  </div>
  <div class="field">
    <%= f.label "Location" %><br>
    <%= collection_select :block, :location_code, Location.all, :location_code, :location_name, {prompt: "Select a location..."}, {class: "form-control"} %>
  </div>
  <div class="field">
    <%= f.label "Scene" %><br>
    <%= collection_select :block, :scene_code, Scene.all, :scene_code, :actAndScene, {prompt: "Select a scene..."}, {class: "form-control"} %>
  </div>
  <div class="field">
    <%= f.label "Block Description" %><br>
    <%= f.text_area :block_description, class: "form-control" %>
  </div>
  <div class="actions">
    <%= f.submit "Create Block", class: "btn btn-primary" %>
  </div>
<% end %>

blocks_controller.rb

class BlocksController < ApplicationController
  before_action :set_block, only: [:show, :edit, :update, :destroy]

  # GET /blocks
  # GET /blocks.json
  def index
    @blocks = Block.all
  end

  # GET /blocks/1
  # GET /blocks/1.json
  def show
  end

  # GET /blocks/new
  def new
    @block = Block.new

    # Set block code as next integer after max block code.
    @block.block_code = (Block.maximum(:block_code).to_i.next).to_s(2)

  end

  # GET /blocks/1/edit
  def edit
  end

  # POST /blocks
  # POST /blocks.json
  def create
    @block = Block.new(block_params)

    respond_to do |format|
      if @block.save
        format.html { redirect_to @block, notice: 'Block was successfully created.' }
        format.json { render :show, status: :created, location: @block }
      else
        format.html { render :new }
        format.json { render json: @block.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /blocks/1
  # PATCH/PUT /blocks/1.json
  def update
    respond_to do |format|
      if @block.update(block_params)
        format.html { redirect_to @block, notice: 'Block was successfully updated.' }
        format.json { render :show, status: :ok, location: @block }
      else
        format.html { render :edit }
        format.json { render json: @block.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /blocks/1
  # DELETE /blocks/1.json
  def destroy
    @block.destroy
    respond_to do |format|
      format.html { redirect_to blocks_url, notice: 'Block was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_block
      @block = Block.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def block_params
      params.require(:block).permit(:block_code, :block_duration, :cue_code, :location_code, :scene_code, :block_description, :cues_attributes => [:cue_code, :cue_type_code, :cue_description, :cue_method_name])
    end
end

block.rb

class Block < ActiveRecord::Base
  has_one :cue, -> { where processed: true }
  accepts_nested_attributes_for :cue, allow_destroy: true

end

cue.rb

class Cue < ActiveRecord::Base
  belongs_to :block
end

cues_controller.rb

class CuesController < ApplicationController
  before_action :set_cue, only: [:show, :edit, :update, :destroy]

  # GET /cues
  # GET /cues.json
  def index
    @cues = Cue.all
  end

  # GET /cues/1
  # GET /cues/1.json
  def show
  end

  # GET /cues/new
  def new
    @cue = Cue.new

    # Set cue code as next integer after max cue code.
    @cue.cue_code = (Cue.maximum(:cue_code).to_i.next).to_s(2)
  end

  # GET /cues/1/edit
  def edit
  end

  # POST /cues
  # POST /cues.json
  def create
    @cue = Cue.new(cue_params)

    respond_to do |format|
      if @cue.save
        format.html { redirect_to @cue, notice: 'Cue was successfully created.' }
        format.json { render :show, status: :created, location: @cue }
      else
        format.html { render :new }
        format.json { render json: @cue.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /cues/1
  # PATCH/PUT /cues/1.json
  def update
    respond_to do |format|
      if @cue.update(cue_params)
        format.html { redirect_to @cue, notice: 'Cue was successfully updated.' }
        format.json { render :show, status: :ok, location: @cue }
      else
        format.html { render :edit }
        format.json { render json: @cue.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /cues/1
  # DELETE /cues/1.json
  def destroy
    @cue.destroy
    respond_to do |format|
      format.html { redirect_to cues_url, notice: 'Cue was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_cue
      @cue = Cue.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def cue_params
      params.require(:cue).permit(:cue_code, :cue_type_code, :cue_description, :cue_method_code)
    end
end

如果还需要什么，请告诉我！（如果格式不好，也很抱歉）。

非常感谢任何帮助！！谢谢！！

更新 1

我目前在 blocks_controller.rb（上文）中的 if @block.save 行收到错误 undefined method 'encoding' for 7:Fixnum。我已经根据 IngoAlbers（下）给出的答案和找到的答案 here.

更改了以下内容

我更改了以下内容：

blocks_controller.rb

def block_params
  params.require(:block).permit(:block_code, :block_duration, :cue_code, :location_code, :scene_code, :block_description, :cue_attributes => [:id, :cue_code, :cue_type_code, :cue_description, :cue_method_code])
end

_form.html.erb - 块

<%= f.fields_for :cue, @block.build_cue do |ff| %>

block.rb

class Block < ActiveRecord::Base
  has_one :cue
  accepts_nested_attributes_for :cue, allow_destroy: true

end

非常感谢迄今为止的帮助！我觉得我真的很接近！

更新 2

所以我添加了 block_id 作为 Cue 的属性和运行以下两个迁移：

class AddBlockIdToCues < ActiveRecord::Migration
  def self.up
    add_column :cues, :block_id, :binary
  end

  def self.down
    remove_column :cues, :block_id
  end
end


class AddBelongsToToCues < ActiveRecord::Migration
  def change
    add_reference :cues, :blocks, index: true
    add_foreign_key :cues, :blocks
  end
end

我仍然在 blocks_controller.rb 中的 if @block.save 行收到错误 undefined method 'encoding' for 7:Fixnum。

Answer 1

问题应该在你的fields_for。应该是：

<%= f.fields_for :cue do |ff| %>

不是 cues 因为它只有一个。然后你需要构建提示。这可以在控制器中或直接在视图中完成，例如：

<%= f.fields_for :cue, @block.build_cue do |ff| %>

在您的块参数中，您还需要将其更改为 cue_attributes，并允许 id.

def block_params
  params.require(:block).permit(:block_code, :block_duration, :cue_code, :location_code, :scene_code, :block_description, :cue_attributes => [:id, :cue_code, :cue_type_code, :cue_description, :cue_method_name])
end

您还可以在此处阅读更多信息：

http://guides.rubyonrails.org/form_helpers.html#nested-forms

关于您的第二次更新：

您的第一次迁移添加了 block_id 类型 binary 的列。它绝对应该是 integer 而不是。也就是说，您甚至根本不需要第一次迁移，因为如果您在 add_reference 中将 blocks 更改为 block，您的第二次迁移将正确处理所有这些。它应该是这样的：

class AddBelongsToToCues < ActiveRecord::Migration
  def change
    add_reference :cues, :block, index: true
    add_foreign_key :cues, :blocks
  end
end

add_reference 需要添加对一个 block 而非多个的引用。这将为您创建正确的列。

另请参阅：http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_reference

Rails Ruby 中的嵌套属性未保存

Nested attributes in Ruby on Rails not saving

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