Rails 邪恶的多步骤表单 - 缺少参数或值为空与不允许的参数

Question

我正在关注 this tutorial 使用 Wicked gem 创建一个多步骤表单。每个用户都有一个答案（用于存储一组问题答案的模型），我有一个问卷控制器，它逐步解决用户将回答并存储在答案中的问题。到目前为止，我只有两个步骤，每个步骤都有一个问题（答案的布尔列 table）。当我逐步回答每个问题时，一切正常，但是当我提交时没有值时，我得到：

param is missing or the value is empty: answer

我的代码...

answer.rb:

class Answer < ApplicationRecord
  belongs_to :user

  cattr_accessor :questionnaire_steps do
    %w(step_one step_two)
  end

  attr_accessor :current_step #stores the current questionnaire step

  validates :user_id, presence: true

  with_options if: -> { required_for_step?(:step_one) } do |step|
    step.validates :question_one, inclusion: [true, false]
  end
  with_options if: -> { required_for_step?(:step_two) } do |step|
    step.validates :question_two, inclusion: [true, false]
  end

  def required_for_step?(step)
    # All fields are required if no questionnaire step is present
    return true if current_step.nil?
    # All fields from previous steps are required if the
    # step parameter appears before or we are on the current step
    return true if self.questionnaire_steps.index(step.to_s) <= self.questionnaire_steps.index(current_step)
  end
end

answers_controller.rb:

class AnswersController < ApplicationController
  before_action :setup

  def setup
    @user = current_user
  end

  def show
    @answer = @user.answer
  end

  def new
    @answer = Answer.new
    @answer = @user.build_answer
    @answer.save(validate: false)
  end

  def create
    @answer = @user.answer
    redirect_to questionnaire_path(@answer, Answer.questionnaire_steps.first)
  end
end

questionnaire_controller.rb:

class QuestionnaireController < ApplicationController
  include Wicked::Wizard

  before_action :setup

  steps *Answer.questionnaire_steps

  def setup
    @user = current_user
  end

  def show
    @answer = @user.answer
    render_wizard
  end

  def update
    @answer = @user.answer
    @answer.update_attributes(answer_params(step))
    render_wizard @answer
  end

  private

  def answer_params(step)
    permitted_attributes = case step
      when "step_one"
        [:question_one]
      when "step_two"
        [:question_two]
    end

    params.require(:answer).permit(permitted_attributes).merge(current_step: step)
  end
end

step_one.html.erb:

<div id="questionnaire" class="container-fluid well inline-headers">
  <%= form_for @answer, method: :put, url: wizard_path do |f| %>
  <div class="row">
    <% if f.object.errors.any? %>
      <div id="error_explanation" class="alert alert-dismissible alert-danger" >
        <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
        <ul>
          <% f.object.errors.each do |attribute, message| %>
            <%= content_tag :li, f.object.errors.full_message(attribute, message), :id => "error_#{attribute}" %>
          <% end %>
        <ul>
      </div>
    <% end %>
  </div>
  <div class="row">
    <div class="col-md-8 form-group">
      <p>Are you any good at this?</p>
    </div>
    <div class="col-md-4 form-group">
      <%= label_tag(:question_one, "Yes") %>
      <%= f.radio_button :question_one, true %>
      <%= label_tag(:question_one, "No") %>
      <%= f.radio_button :question_one, false %>
    </div>
  </div>
  <div class="row">
    <div class="col-md-4 col-md-offset-8 form-group">
      <p><%= f.submit "Save & Continue", class: "btn btn-warning" %></p>
    </div>
  </div>
  <% end %>
</div>

routes.rb（诚然，我试图用这些来掩盖 ID，请随意羞辱我以正确的方式做到这一点）：

resources :answers, only: [:show, :new, :create]
  get 'user/questionnaire', to: 'answers#show'
  get 'user/questionnaire/new', to: 'answers#new'
  post 'user/questionnaire/new', to: 'answers#create'

resources :questionnaire

当我 select 一个选项并提交时，它会保存到数据库并重定向到下一步，但是如果我在没有 select 一个选项的情况下提交，我会收到参数丢失错误我希望得到验证错误。来自服务器日志：

Processing by QuestionnaireController#update as HTML Parameters: {"utf8"=>"��", "authenticity_token"=>"J45sG/YIqTaBECgBqNLr9Ys3rJewDK78d/cKHWFHYEIzAaOiTXhgH6evPZKl5LhnSAMnQnA94CXonqriyj0fCQ==", "commit"=>"Save & Continue", "id"=>"step_one"}

我尝试了一些可能的修复方法，包括从 params.require(:answer).permit(permitted_attributes).merge(current_step: step) 中删除 require(:answer)，这让我得到了我预期的验证错误，但不允许保存有效值。在那种情况下，我仍然在服务器日志中收到以下验证错误：

Started PUT "/questionnaire/step_one" for ::1 at 2016-12-08 23:26:14 +0545 Processing by QuestionnaireController#update as HTML
Parameters: {"utf8"=>"��", "authenticity_token"=>"RWAHfu0BE82ik6gTChh3nmtuyOUa5j0qiz4H03ejIkRR78jHVnHa5IQsvYAHLiQMqFpDMNrXc/MUV6cs3NldDw==", "answer"=>{"question_one"=>"true"}, "commit"=>"Save & Continue", "id"=>"step_one"} ...SQL... Unpermitted parameters: utf8, _method, authenticity_token, answer, commit, id

非常感谢您帮助菜鸟。

更新：我修改了我的路线以匹配教程（嵌套）认为这可能与它有关（即可能没有得到答案 ID）但我仍然收到参数丢失错误。

resources :answers, only: [:show, :new, :create] do
    resources :questionnaire, only: [:show, :update], controller: 'questionnaire'
  end
  get 'user/questionnaire', to: 'answers#show'
  get 'user/questionnaire/new', to: 'answers#new'
  post 'user/questionnaire/new', to: 'answers#create'

我也试过在提交前加一个hidden_field_tag，像这样：

<%= hidden_field_tag(:answer, @answer) %>

但后来我得到：

undefined method `permit' for #

可能是因为当强参数声明需要散列时，hidden_field_tag 将 @answer.attributes 作为字符串传递。来自服务器：

Started PUT "/answers/46/questionnaire/step_one" for ::1 at 2016-12-12 13:25:19 +0545 Processing by QuestionnaireController#update as HTML Parameters: {"utf8"=>"��", "authenticity_token"=>"wlLpKoMvqgyfwB5gyP/qubR4ZpZa6jm9KHeMuiwJTc6IOJZi9PgiSegvF+OzlN09ctEuxuxiAuRs+/B2InRGhA==", "answer"=>"{\"id\"=>46, \"user_id\"=>4, \"question_one\"=>nil, \"question_two\"=>nil, \"percentage_complete\"=>#, \"completed\"=>false, \"created_at\"=>Mon, 12 Dec 2016 02:12:31 EST -05:00, \"updated_at\"=>Mon, 12 Dec 2016 02:12:31 EST -05:00}", "commit"=>"Save & Continue", "answer_id"=>"46", "id"=>"step_one"}

请帮忙！

Answer 1

问题是否仍然有效？

我想把它放在评论中，但不能。我认为问题在于验证。它会检查您是否在相关字段中输入了值，如果没有输入则抛出错误。如果从模型中删除 step.validates 会怎样？

Answer 2

我将 params.require 更改为 params.fetch 并且有效（正确触发了验证，我也可以成功完成具有有效值的步骤）。

Rails 邪恶的多步骤表单 - 缺少参数或值为空与不允许的参数

Rails Wicked multi step form - param is missing or the value is empty vs unpermitted parameters

ruby-on-rails

strong-parameters

wicked-gem