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Nested attributes in Ruby on Rails not saving

由 a 夏天 提交于 2019-12-10 23:53:22

问题


I'll preface this by saying I've looked at the following answers and still have not hit a solution that works (however, given the possibility I might have overlooked something, I'm including them for reference):

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

Description of problem: I have a form Block with a nested form for Cue. The form renders correctly and the Block saves correctly, but the Cue does not appear in the Cue table, i.e. the Cue isn't saving when the Block is submitted. I'm using Rails 4.2.5.1. I also don't get any errors on submit, making this a bit difficult to diagnose.

Code:

_form.html.erb - block

<%= 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

If anything else is needed, please let me know! (Also sorry if the formatting isn't great).

Any help is much appreciated!! Thanks!!

UPDATE 1

I'm currently getting the error undefined method 'encoding' for 7:Fixnum on the line if @block.save in blocks_controller.rb (above). I have changed the following things based on the answer given by IngoAlbers (below) and the answer found here.

I've changed the following things:

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

Thanks so much for the help so far! I think I'm really close!

UPDATE 2

So I've added block_id as an attribute to Cue and run the following two migrations:

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

I'm still getting the error undefined method 'encoding' for 7:Fixnum on the line if @block.save in the blocks_controller.rb.


回答1:


The problem should be in your fields_for. It should probably be:

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

Not cues since it is only one. Then you need to build the cue. This can be done either in controller or in the view directly, for example like this:

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

In your block params you then also need to change it to cue_attributes, and also allow 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

You can also read a lot more information here:

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

Regarding your second Update:

Your first migration adds a column block_id of type binary. It should definitely be integer instead. That said, you don't even need the first migration at all, because your second migration will handle all of it correctly, if you change blocks to block in add_reference. It should look like this:

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

The add_reference needs to add a reference to one block not multiple. This will then create the right column for you.

See also: http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_reference



来源：https://stackoverflow.com/questions/36145305/nested-attributes-in-ruby-on-rails-not-saving

标签
ruby-on-rails
forms
ruby-on-rails-4
nested-attributes
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