Afficher le message d'erreur

■ Amélioration de l'UX ■ Meilleure compréhension des modèles partiels
■ Mac OS catalina ■ Ruby on Rails (5.2.4.2) ■ Virtual Box:6.1 ■ Vagrant: 2.2.7
mac.terminal
$ rails new error_test
$ cd error_test
$ rails g scaffold Item name:string texte:text amount:integer
$ rails db:migrate
$ cd app/views/layouts
$ touch _error_messages.html.erb
models/item.rb
class Item < ApplicationRecord
  validates :name, presence: true
  validates :text, presence: true
  validates :amount, presence: true
end
layputs/_error_messages.html.erb
<% if model.errors.any? %>
  <div class="alert alert-warning">
    <ul>
      <% model.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
    </ul>
  </div>
<% end %>
※ajouter
Items/_form.html.erb
<%= render 'layouts/error_messages', model: f.object %>
/_form.....
<% if item.errors.any? %>
<div id="error_explanation">
  <h2><%= pluralize(item.errors.count, "error") %> prohibited this item from being saved:</h2>
  <ul>
    <% item.errors.full_messages.each do |message| %>
    <li><%= message %></li>
    <% end %>
  </ul>
</div>
<% end %>
L'échafaudage d'origine

Partiel

c'est tout. comme vous voulez! !! !!
■ Concernant les messages d'erreur https://qiita.com/ryuuuuuuuuuu/items/1a1e53d062bff774d88a
■hidden_field https://qiita.com/tanaka-yu3/items/0d454c5ef80f8267f09d
■ Création d'applications https://qiita.com/tanaka-yu3/items/3fe1ed2852c6513d3583