jquery,keypress,enter,keycode

        $('.serchStockInput').keypress(function (e) {
          if(e.keyCode == 13) {
            track();
            return false;
          }
        });

composed_of,model,data object

http://hideto.javaeye.com/blog/77459
http://rorataspire.wordpress.com/2008/07/10/rails-composed_of/
http://api.rubyonrails.org/classes/ActiveRecord/Aggregations/ClassMethods.html#M001663
http://opensoul.org/2006/11/16/making-code-composed_of-code-more-useful

composed_of 感覺就是用來把妳一些 field 在弄成一個 object, 當然也就可以拿這個 value object  產生出新的 object, 也可以用在find 裡面當條件用

   1. class Person < ActiveRecord::Base
  2.   composed_of :address,
  3.               :class_name => "Address",
  4.               :mapping => [%w(address_street street),
  5.                            %w(address_city city),
  6.                            %w(address_state state),
  7.                            %w(address_country country)]
  8. 
  9. class Address
 10.   attr_accessor :street, :city, :state, :country
 11.   def initialize(street, city, state, country)
 12.     @street = street
 13.     @city = city
 14.     @state = state
 15.     @country = country
 16.   end
 17. end

person.address = Address.new(...)  
person.save
person.address.city = "LA"  
person.save
這不會更新person的city字段，因為composed_of()的值對象被認為是immutable的，而只有new一個Address對象才能保存


class UserData
 attr_accessor :name

 def initialize(name)
   @name = name
 end
end

class User < ActiveRecord::Base
  composed_of :user_data, :mapping =>%w(name name)   <= 其實是這樣 ["name", "name"]
end

現在就可以用這樣了
>> u = UserData.new('ilake')
=> #<UserData:0xb7197f28 @name="ilake">
>> User.find(:all, :conditions => {:user_data => u})
=> [#<User id: 5, name: "ilake"]

module_eval,class_eval,singleton

http://onestepback.org/articles/10things/page027.html
http://my.donews.com/idlecat/2006/08/20/IpzenftEYkWGFjJpxPTDTJTCDOGKqTPzCaPZ/llllll
http://blackanger.blog.51cto.com/140924/84057
http://fcamel.twbbs.org/archives/2008/04/07/474/
http://tw.myblog.yahoo.com/weijenlu/article?mid=99&prev=109&next=-1

class Module
  def trace_attr(sym)
  self.module_eval <<-EOS      <= 也可以說是動態產生 method 的方法
     def #{sym}
          printf "Accessing %s with value %s\n",
        "#{sym}", @#{sym}.inspect
        @#{sym}
      end
   EOS
   end
end

class Dog
trace_attr :name
def initialize(string)
   @name = string
end
end
p Dog.new("Fido").name

class Test
end

code =<<-EOF
   def hello_module
     'hello world, use module'
    end
EOF Test.module_eval(code)          <= 動態塞段 code 進去, method 就生了, 太神啦 
p Test.new.hello_module()


Test.class_eval <<-END          <= 有直接塞進class的 fu
def hello_class
'  hello world, use class'
end
END
p Test.new.hello_class()

t = Test.new
class << t                      <= 可以直接塞method 進  t 這個  object
 def hello_singleton
   'hello singleton'
 end
end

class << Test                <= Test class也是 oject 當然也可以塞
 def class_singleton       
   'class singleton'
 end
end


class Announce < ActiveRecord::Base
 require_dependency 'forum/forum_model_mixin'
 include ForumModelMixin
end

module ForumModelMixin
 def self.included(klass)                  <= klass可以知道是哪個 class include了這個lib
     klass.class_eval do               

     has_many :forum_comments, :as => :forum
     alias_method :old_destroy, :destroy
     validates_presence_of :content, :subject, :user_id

     def destroy(r)
       if r
         old_destroy
       else
         update_attribute(:removed_at, Time.now)  if !removed_at
       end
     end
   end
 end
end

Dir,entries,glob

http://www.ruby-doc.org/core/classes/Dir.html

Dir.entries("#{RAILS_ROOT}/public/images/score/1")
=> ["victory_32.png", "..", "victory_128.png", "victory_64.png", "."]

Dir.glob("#{RAILS_ROOT}/public/images/score/1")
=> ["/home/lake/rails_app/iwakela/public/images/score/1"]

instance_variable_get,delegate

http://ihower.idv.tw/blog/archives/1719
http://blog.gugl.org/archives/41
http://www.ruby-doc.org/core/classes/Object.html#M000380
http://www.ruby-doc.org/core/classes/Module.html#M001677
http://www.ruby-doc.org/core/classes/Hash.html#M002868


KEYS_MAPPINGS.each do |key, value|
define_method key, lambda {                    <= 用來生 method 的 method
instance_variable_get('@hash')[value]       <= 可以直接拿 @hash instance variable 的 值
}
end


  KEYS_MAPPINGS = {
    :ask       =>  'BSELL' ,    :bid     =>  'BBUY'    ,
    :change  =>  'CHANGE',   :high   =>  'HIGH',
:target_id   =>  'STKID' ,  :target_name =>  'STKNAME'
  }

 delegate_opts = MarketData::KEYS_MAPPINGS.keys.reject do |e|
e == :target_id || e== :target_name
end.push(:to => :market_data)            <= 呼叫 名為 market_data的 instance _function, 一般常是 has_one :thing 的 thing, 不過一樣意思, 就是叫後面這個 function
delegate *delegate_opts                      <= delegate_opts = [:ask, :bid, :change, :high, {:to => :market_data}]
                                                           <= delegate *delegate_opts 就是  delegate :ask, :bid, :change, :high, :to => :market_data
                                                           <= delegate 可以一次傳入多個 parameter
def market_data(key=nil)     
@market_data ||= MarketData.target(target_id)
key && @market_data ?  @market_data[key] : @market_data     <= 有傳 key 跟沒傳key return的東西不同
end


[User model]
 has_one :profile

 field = Profile.content_columns.inject([]) do |result, column|   <= content_columns, 濾掉 _id, _count的那些
   result << column.name
 end.push(:to => :profile)

 delegate *field

 User.first.address      <= 現在可以直接這樣用了

has_many,through,source,source_type,foregin_key,class_name

  #我發表過forum的comments
  has_many :forum_comments, :through => :forums, :source => :comments

 
  #forum 裡有我的 comments的 forum, 找出 forum array
  has_many :forums_has_comments,
           :through => :comments,
           :source  => :record,
           :source_type => 'Forum'

  #我在forum 裡所有的comments, 找出 comments array
  has_many :comments_in_forums,
           :foreign_key => :user_id,
           :class_name => 'Comment',
           :conditions => {:record_type => 'Forum'}

rails,version,uninstall

rails _2.0.2_ your_old_rails_project <= 指定用哪個版本rails 去安裝
sudo gem uninstall rails -v 2.1.0 <= 移除某個版本的rails