我会先说明我已经看过以下答案但仍然没有找到有效的解决方案（但是，考虑到我可能忽略某些东西的可能性，我将它们包括在内作为参考）：
问题描述：我有一个带有Cue嵌套表单的表单块。表单正确呈现并且块保存正确，但Cue没有出现在Cue表中，即提交块时Cue不保存。我正在使用Rails 4.2.5.1。我也没有提交任何错误，这使得诊断有点困难。
代码：
_form.html.erb - 阻止
<%= 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
如果还有其他需要，请告诉我！ （如果格式不是很好，也很抱歉。）
非常感谢任何帮助!!谢谢！
更新1
我目前在undefined method 'encoding' for 7:Fixnum（上面）的if @block.save行上收到错误blocks_controller.rb。我根据IngoAlbers（下方）给出的答案以及找到的答案here更改了以下内容。
我改变了以下内容：
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 - blocks
<%= 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
非常感谢你们的帮助！我想我真的很亲密！
更新2
所以我已将block_id作为属性添加到Cue并运行以下两个迁移：
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undefined method 'encoding' for 7:Fixnum的{{1}}行上收到错误if @block.save。
答案 0 :(得分：2)
问题应该出在fields_for。应该是：
<%= f.fields_for :cue do |ff| %>
不是cues，因为它只有一个。然后你需要建立提示。这可以在控制器中直接在视图中完成，例如：
<%= f.fields_for :cue, @block.build_cue do |ff| %>
在您的区块参数中，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：
您的第一次迁移会添加block_id类型的列binary。它绝对应该是integer。也就是说，您根本不需要首次迁移，因为如果您在blocks中将block更改为add_reference，则第二次迁移将正确处理所有迁移。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的引用而不是多个引用。然后，这将为您创建正确的列。