Ruby on rails Rails：创建无效记录后的错误不会显示

我正在尝试创建一个简单的应用程序，它允许属于group-groups表的登录用户创建一个group事务。但是，在我提交了无效的formI have验证后，我没有收到任何错误

这是我的控制器：

class GroupTransactionsController < ApplicationController
  before_action :get_group, only: [:new, :create, :destroy, :index, :show]
  before_action :how_many_members, only: [:new, :show, :create]
  before_action :set_transaction_number, only: [:index]

  def new
    @group_transaction = @group.group_transactions.new
    @members.times { @group_transaction.group_transaction_borrowers.build }
  end 

  def create
    @group_transaction = @group.group_transactions.build(group_transactions_params)

    if @group_transaction.save
      flash[:success] = "Group transactions has been made"
      redirect_to group_group_transactions_path(@group)
    else  
      render 'new' 
    end
  end

  private

  def group_transactions_params
    params.require(:group_transaction).permit(:issuer_id, :value, :description, 
                                          group_transaction_borrowers_attributes: 
                            GroupTransactionBorrower.attribute_names.map(&:to_sym))
    #output of the line above: [:id, :created_at, :updated_at, :group_transactions_id, 
     :borrower_id]                                                                                                                                               
  end 

  def get_group
    @group = Group.find(params[:group_id])
  end 

  def how_many_members
    @members = Group.find(params[:group_id]).relations.count 
  end 

end

<%= provide(:title, "New group transaction") %>
<div class="row">
  <div class="col-md-6 col-md-offset-3">
  <%= form_with(model: [@group, @group_transaction],url: 
      group_group_transactions_path,class: "new_transaction") do |f| %>
    <!-- show error messages render error partial -->
    <%= render "shared/error_group_transactions" %>

    <%= hidden_field_tag "group_transaction[issuer_id]", current_user.id %>

  
    <%= f.fields_for :group_transaction_borrowers do |borrower| %>  
      <%= borrower.label :borrower_id, "Borrower name" %>
      <%= borrower.collection_select(:borrower_id, group_members(@group.id), :id, :name,
                            { include_blank: 'Please select borrower' }) %>

    <% end %>

    <%= label_tag :value, "Value" %>
    <%= f.number_field :value, step: 0.01 %>

    <%= label_tag :description, "Description" %>
    <%= f.text_field :description %>

    <%= f.submit "Make Transaction!", class: "btn btn-primary" %>

  <% end %>
</div>

当我提交带有空字段的表单时，我不会收到错误消息。但是，似乎呈现了_error_group_transactions partial检查日志信息如下。 提交表单后的日志，包含空字段：

Started POST "/groups/6/group_transactions" for ::1 at 2020-10-18 16:46:04 +0200
   (0.1ms)  SELECT sqlite_version(*)
Processing by GroupTransactionsController#create as JS
  Parameters: {"authenticity_token"=>"3GVrvgeGCZ/UMVy5He9LA3d96A5uchEeDknUxduNiuvQYJE2UDeyzarcOrApD2pYYSSMAHLzwBrE3acK9aBkhw==", "group_transaction"=>{"issuer_id"=>"21", "group_transaction_borrowers_attributes"=>{"0"=>{"borrower_id"=>""}, "1"=>{"borrower_id"=>""}}, "value"=>"", "description"=>""}, "commit"=>"Make Transaction!", "group_id"=>"6"}
  User Load (0.8ms)  SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT ?  [["id", 21], ["LIMIT", 1]]
  ↳ app/helpers/session_helper.rb:27:in `current_user'
  Group Load (1.0ms)  SELECT "groups".* FROM "groups" WHERE "groups"."id" = ? LIMIT ?  [["id", 6], ["LIMIT", 1]]
  ↳ app/controllers/group_transactions_controller.rb:77:in `get_group'
  CACHE Group Load (0.0ms)  SELECT "groups".* FROM "groups" WHERE "groups"."id" = ? LIMIT ?  [["id", 6], ["LIMIT", 1]]
  ↳ app/controllers/group_transactions_controller.rb:81:in `how_many_members'
   (0.7ms)  SELECT COUNT(*) FROM "relations" WHERE "relations"."group_id" = ?  [["group_id", 6]]
  ↳ app/controllers/group_transactions_controller.rb:81:in `how_many_members'
  CACHE User Load (0.0ms)  SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT ?  [["id", 21], ["LIMIT", 1]]
  ↳ app/controllers/group_transactions_controller.rb:21:in `create'
  Rendering group_transactions/new.html.erb within layouts/application
  <h2>Rendered shared/_error_group_transactions.html.erb (Duration: 16.8ms | Allocations: 551)</h2>
  Rendered group_transactions/new.html.erb within layouts/application (Duration: 40.3ms | Allocations: 1051)
[Webpacker] Everything's up-to-date. Nothing to do
  Rendered layouts/_shim.html.erb (Duration: 0.0ms | Allocations: 5)
  Rendered layouts/_header.html.erb (Duration: 1.7ms | Allocations: 358)
  Rendered shared/_flash_messages.html.erb (Duration: 0.1ms | Allocations: 17)
  Rendered layouts/_footer.html.erb (Duration: 0.1ms | Allocations: 27)
Completed 200 OK in 508ms (Views: 217.4ms | ActiveRecord: 2.6ms | Allocations: 37732)

我可以提供额外的代码，如果你想。 如果你能帮我，我将不胜感激。 提前感谢,，

---

Lukas

首先，我将使用局部变量而不是实例变量来创建一个适当的通用错误部分：

# shared/errors.html.erb
<% if object.errors.any? %>
 <div id="error_explanation">
    <div class="alert alert-danger">
      <%= pluralize(object.errors.count, "error") %> occured 
    </div>
      <ul>
        <% object.errors.full_messages.each do |msg| %>
          <li><%= msg %></li>
        <% end %>
      </ul>
  </div>
<% end %>

这会将您的部分内容从依赖于视图上下文状态的内容更改为一个简单的函数，在该函数中，您只需提供输入并呈现HTML。因此，它可以呈现任何给定模型的错误

然后渲染主对象的错误以及每个嵌套对象的错误：

<div class="row">
  <div class="col-md-6 col-md-offset-3">
  <%= form_with(model: [@group, @group_transaction], url: 
      group_group_transactions_path, class: "new_transaction") do |f| %>
    <%= render "shared/errors", object: f.object %>

    <%= hidden_field_tag "group_transaction[issuer_id]", current_user.id %>

    <%= f.fields_for :group_transaction_borrowers do |borrower| %>  
      <%# renders the errors for this borrower %>
      <%= render "shared/errors", object: borrower.object %>
      <%= borrower.label :borrower_id, "Borrower name" %>
      <%= borrower.collection_select(:borrower_id, group_members(@group.id), :id, :name,
                            { include_blank: 'Please select borrower' }) %>
    <% end %>

    <%= label_tag :value, "Value" %>
    <%= f.number_field :value, step: 0.01 %>
    <%= label_tag :description, "Description" %>
    <%= f.text_field :description %>
    <%= f.submit "Make Transaction!", class: "btn btn-primary" %>
  <% end %>
</div>

在旁注隐藏的\u字段\u标记组\u事务[issuer\u id]上，当前的\u user.id闻起来像是一个严重的安全问题。这使得恶意用户使用web inspector或cURL发送他们想要的任何id变得微不足道。相反，使用更难篡改的会话作为加密cookie。

 Rails.application.routes.draw do
   #other routes
   resources :groups do 
     resources :group_transactions, only: [:destroy, :show, :create, :new, :index]
   end
 end

Started POST "/groups/6/group_transactions" for ::1 at 2020-10-18 16:46:04 +0200
   (0.1ms)  SELECT sqlite_version(*)
Processing by GroupTransactionsController#create as JS
  Parameters: {"authenticity_token"=>"3GVrvgeGCZ/UMVy5He9LA3d96A5uchEeDknUxduNiuvQYJE2UDeyzarcOrApD2pYYSSMAHLzwBrE3acK9aBkhw==", "group_transaction"=>{"issuer_id"=>"21", "group_transaction_borrowers_attributes"=>{"0"=>{"borrower_id"=>""}, "1"=>{"borrower_id"=>""}}, "value"=>"", "description"=>""}, "commit"=>"Make Transaction!", "group_id"=>"6"}
  User Load (0.8ms)  SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT ?  [["id", 21], ["LIMIT", 1]]
  ↳ app/helpers/session_helper.rb:27:in `current_user'
  Group Load (1.0ms)  SELECT "groups".* FROM "groups" WHERE "groups"."id" = ? LIMIT ?  [["id", 6], ["LIMIT", 1]]
  ↳ app/controllers/group_transactions_controller.rb:77:in `get_group'
  CACHE Group Load (0.0ms)  SELECT "groups".* FROM "groups" WHERE "groups"."id" = ? LIMIT ?  [["id", 6], ["LIMIT", 1]]
  ↳ app/controllers/group_transactions_controller.rb:81:in `how_many_members'
   (0.7ms)  SELECT COUNT(*) FROM "relations" WHERE "relations"."group_id" = ?  [["group_id", 6]]
  ↳ app/controllers/group_transactions_controller.rb:81:in `how_many_members'
  CACHE User Load (0.0ms)  SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT ?  [["id", 21], ["LIMIT", 1]]
  ↳ app/controllers/group_transactions_controller.rb:21:in `create'
  Rendering group_transactions/new.html.erb within layouts/application
  <h2>Rendered shared/_error_group_transactions.html.erb (Duration: 16.8ms | Allocations: 551)</h2>
  Rendered group_transactions/new.html.erb within layouts/application (Duration: 40.3ms | Allocations: 1051)
[Webpacker] Everything's up-to-date. Nothing to do
  Rendered layouts/_shim.html.erb (Duration: 0.0ms | Allocations: 5)
  Rendered layouts/_header.html.erb (Duration: 1.7ms | Allocations: 358)
  Rendered shared/_flash_messages.html.erb (Duration: 0.1ms | Allocations: 17)
  Rendered layouts/_footer.html.erb (Duration: 0.1ms | Allocations: 27)
Completed 200 OK in 508ms (Views: 217.4ms | ActiveRecord: 2.6ms | Allocations: 37732)

# shared/errors.html.erb
<% if object.errors.any? %>
 <div id="error_explanation">
    <div class="alert alert-danger">
      <%= pluralize(object.errors.count, "error") %> occured 
    </div>
      <ul>
        <% object.errors.full_messages.each do |msg| %>
          <li><%= msg %></li>
        <% end %>
      </ul>
  </div>
<% end %>

<div class="row">
  <div class="col-md-6 col-md-offset-3">
  <%= form_with(model: [@group, @group_transaction], url: 
      group_group_transactions_path, class: "new_transaction") do |f| %>
    <%= render "shared/errors", object: f.object %>

    <%= hidden_field_tag "group_transaction[issuer_id]", current_user.id %>

    <%= f.fields_for :group_transaction_borrowers do |borrower| %>  
      <%# renders the errors for this borrower %>
      <%= render "shared/errors", object: borrower.object %>
      <%= borrower.label :borrower_id, "Borrower name" %>
      <%= borrower.collection_select(:borrower_id, group_members(@group.id), :id, :name,
                            { include_blank: 'Please select borrower' }) %>
    <% end %>

    <%= label_tag :value, "Value" %>
    <%= f.number_field :value, step: 0.01 %>
    <%= label_tag :description, "Description" %>
    <%= f.text_field :description %>
    <%= f.submit "Make Transaction!", class: "btn btn-primary" %>
  <% end %>
</div>