[Ruby on Rails] Learn from me (10) Data Entry validation

Here simply add a few validations, non-empty, minimum length, unique

Modifying a model

Modify the App/models/post.rb file as follows:

class Post < ActiveRecord::Base
  #attr_accessible :title, :content
  validates :title, :context, :presence => true
  validates :title, :length => { :minimum =>2}
  validates :title, :uniqueness => { :message =>‘Already taken‘}
end

At this time to run the service, modify/New model, when nothing is filled, can not be submitted, nor error.

What's the reason?

Because you didn't show the error message.

Modify views

Modify the App/views/posts/new.html.erb file as follows:

<h1>Add a new post</h1>

<%= form_for @post do |f| %>
  <%if @post.errors.any? %>
  <h3>Errors</h3>
  <ul>
    <% @post.errors.full_messages.each do |msg| %>
      <li><%=msg%></li>
    <% end %>
  </ul>
  <%end%>
  <p>
   <%= f.label :title%><br/>
   <%= f.text_field :title%>
  </p>
  <p>
   <%= f.label :context%><br/>
   <%= f.text_area :context%>
  </p>
  <p>
   <%= f.submit "New Post"%>
  </p>

Add

<%if @post.errors.any? %>
  <h3>Errors</h3>
  <ul>
    <% @post.errors.full_messages.each do |msg| %>
      <li><%=msg%></li>
    <% end %>
  </ul>
  <%end%>

For app / views / posts / edit.html.erb do the same.

 

Run service
rails s -b 192.168.xxx.xxx -p 3000, add a record, and submit directly without filling in any messages. The verification message is as follows:

  Reprinted please indicate this article from: http://www.cnblogs.com/Tommy-Yu/p/4143036.html, thank you!

[ruby on rails] Follow me (10) Data input verification