实例：
$ git clone git://github.com/RailsApps/rails3-devise-rspec-cucumber.git
$ bundle install
$ rake db:migrate
在config/environments/production.rb文件中修改代码：
config.serve_static_assets = false
==================================
protect_from_forgery
<%= csrf_meta_tags %>
===================================
VIEW
<% if user_signed_in? %>
Controller
before_filter :authenticate_user!
before_filter :authenticate_user!, :only => [:edit]
routes
authenticated :user do
resources :users
end
Helpers
current_admin
current_user
=================== model ===============
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable, :confirmable
## Database authenticatable
field :login_name, :type => String, :default => ""
field :encrypted_password, :type => String, :default => ""
## Recoverable
field :reset_password_token, :type => String
field :reset_password_sent_at, :type => Time
## Rememberable
field :remember_created_at, :type => Time
## Trackable
field :sign_in_count, :type => Integer, :default => 0
field :current_sign_in_at, :type => Time
field :last_sign_in_at, :type => Time
field :current_sign_in_ip, :type => String
field :last_sign_in_ip, :type => String
## Confirmable
# field :confirmation_token, :type => String
# field :confirmed_at, :type => Time
# field :confirmation_sent_at, :type => Time
# field :unconfirmed_email, :type => String # Only if using reconfirmable
## Lockable
# field :failed_attempts, :type => Integer, :default => 0 # Only if lock strategy is :failed_attempts
# field :unlock_token, :type => String # Only if unlock strategy is :email or :both
# field :locked_at, :type => Time
## Token authenticatable
# field :authentication_token, :type => String
=================================
1：Encryptable:除了内置的Bcrypt(默认)，增加支持认证机制
2：Lockable:锁定一定数量的失败尝试登录。通过电子邮件或之后才能解锁
3：validatable：有效性：提供的电子邮件及密码鉴定。它是可选的,可定制的,所以你可以定义自己的代码。
4：Timeoutable：在一特定时期（expires sessions）没有活动。
5：Trackable（跟踪）：追踪 登录的次数、时间戳记签字和IP地址
6：Rememberable（记忆）：管理产生和清除表示来自用户保存的cookie的标记（token）
7：Registerable（注册）：处理用户注册过程,也可以让他们编辑和摧毁他们的帐户。
8：recoverable（重设）重置用户密码并且发送重置指令。
9：Confirmable注册登录认证
10：Omniauthable: adds Omniauth (github.com/intridea/omniauth) support;
11：Database Authenticatable: encrypts and stores a password in the database to validate the authenticity of a user while signing in. The authentication can be done both through POST requests or HTTP Basic Authentication.
12：Token Authenticatable: signs in a user based on an authentication token (also known as “single access token”). The token can be given both through query string or HTTP Basic Authentication.
通过Divse 添加Users
其中User.rb可用属性：12个
:token_authenticatable, :encryptable, :confirmable, :lockable, :timeoutable ， :omniauthable ，
:database_authenticatable, :registerable, :recoverable, :rememberable, :trackable, :validatable,
使用：
1：Gemfile中加入： gem 'devise'
2：建立devise档案： rails g devise：install（自动在routes.rb中加入：devise_for:user）
3：预设定网站网址：在config/environmentents/development.rb与production.rb中加入
config.action_mailer.default_url_options = { :host => 'localhost:3000' }
4：在app/views/layouts/application.html.erb layout中加入：（提示flash信息）
<p class="notice"><%= notice %></p>
<p class="alert"><%= alert %></p>
5：设定主页,在routes.rb中
root :to => ""
6:产生User model以及Migration
rails g devise user
7:如果需要E-mail验证登录功能，修改user.rb migration将confirmable打开
8：产生view模板
rails g devise：views
9：建立资料表
rake db：migration
使用：
在需要登录的control中加上：before_filter:authenticate_user!
！！
定制登录信息：（注意修改：）
devise默认是email和密码登录，那么，现在用用户名登录！配置如下：
1：添加username字段到User表单
rails generate migration add_username_to_users username:string
rake db:migration
2：修改配置文件：是devise默认用username登录/config/initializers/devise.rb
config.authentication_keys = [ :username ]
config.sign_out_via = :get
3:修改注册页面，app\views\devise\registrations\new.html.erb(类似修改其他devise的视图)
<h2>Sign up</h2>
<%= form_for(resource, :as => resource_name, :url => registration_path(resource_name)) do |f| %>
<%= devise_error_messages! %>
<p><%= f.label :username %><br />//////
<%= f.text_field :username %></p>//////
<p><%= f.label :email %><br />
<%= f.email_field :email %></p>
<p><%= f.label :password %><br />
<%= f.password_field :password %></p>
<p><%= f.label :password_confirmation %><br />
<%= f.password_field :password_confirmation %></p>
<p><%= f.submit "Sign up" %></p>
<% end %>
<%= render :partial => "devise/shared/links" %>
4：重启服务-效果成功