# [Ruby On Rails]使用i18n客製化表單驗證的錯誤訊息

###### tags: `Ruby On Rails`

參考網址:
https://stackoverflow.com/questions/17935597/ruby-on-rails-i18n-want-to-translate-custom-messages-in-models

# MODEL

models/article.rb

class Article < ApplicationRecord
    
    validates :title, presence: true,
        length:{minimum:5,too_short: :en_article_title_too_short}

end

# VIEW

views/articles/new.html/erb

<h2>new articles</h2>

<%= form_for :article ,url:articles_path do |f| %>


<% if @article.errors.any? %>
    <ul>
        <% @article.errors.full_messages.each do |msg| %>
        <li><%=msg%></li>
        <% end %>
    </ul>
<% end %>


    <p>
        <%= f.label :title,"TITLE" %><br>
        <%= f.text_field :title %>
    </p>
    <p>
        <%= f.label :text, "text" %><br>
        <%= f.text_area :text %>
    </p>
    <p>
        <%= f.submit "SAVE"%>
    </p>
<% end %>

# CONTROLLER

controllers/articles_controller.rb

#...

def new
        @article=Article.new
    end

    def create

        @article=Article.new(article_params)
        
        # form validation
        if @article.save
            redirect_to @article
        else
            render 'new' #maintain user input
        end
    end
    
    private
    def article_params
        params.require(:article).permit(:title,:text)
    end
    

# i18n

config/locales/en.yml

en:
  
  errors:
    format: "%{message}"

  activerecord:
    errors:
      models:
        article: # or namespace/model_name
          attributes:
            title:
              en_article_title_too_short: "title format incorrect(at least 5 character)"