在这章迭代里，主要是新建用户表单，没用插件，代码如下： user.erb

class User < ActiveRecord::Base
  #这里的password、password_confirmation是虚拟属性
  attr_accessor :password_confirmaton
  validates_confirmation_of :password
end

users_controller.rb

class UsersController < ApplicationController
  def create
    p "------#{params[:user][:password]}----#{params[:user][:password_confirmaton]}--------"
    @user = User.new(params[:user])
    respond_to do |format|
      if @user.save
        flash[:notice] = "User #{@user.name} was successfully created. "
        format.html { redirect_to(:action => "index") }
      else
        format.html { render :action => "new" }
      end
    end
  end
end

users/new.html.erb

<h1>New user</h1>
<% form_for(@user) do |f| %>
  <%= f.error_messages %>
  <fieldset>
    <legend>Enter User Details</legend>
    <div>
      <%= f.label :user_password, 'Password' %><br />
      <%= f.password_field :password, :size => 40 %>
    </div>
    <div>
      <%= f.label :user_password_confirmaton, 'Confirm' %><br />
      <%= f.password_field :password_confirmaton, :size => 40 %>
    </div>
    <div>
      <%= f.submit 'Add User', :class => "submit" %>
    </div>
  </fieldset>
<% end %>

<%= link_to 'Back', users_path %>

保存新用户时确认密码不填或者和密码不一致 表单都会保存成功 但是自己加的验证：

attr_accessor :password, :password_confirmaton
validates_presence_of :password_confirmation, :if => :password_changed?
validates_confirmation_of :password
  def password_changed?
    errors.add(:password_confirmation, " no match password ") if password_confirmation != password
  end

在提交表单时 会提示

这个错误 可是我填写密码和确认密码 并且他们相等 求各位闲暇时看下 谢谢了