// 这里使用了Twitter4R
* v0.2.0，Twitter4R是用ruby写的一个libï¼Œå¯ä»¥ç”¨æ * ¥è®¿é—®Twitter REST APIs
// Twitter4R的地址 http://twitter4r.rubyforge.org

 1  require('rubygems')
 2  gem('twitter4r', '>=0.2.0')
 3  require('twitter')
 4  
 5  login = 'mylogin' # change this
 6  password = 'mypass' # change this
 7  friend = 'myfriend' # change this
 8  
 9  client = Twitter::Client.new(:login => login, :password => 
    password)
10  public_timeline = client.timeline_for(:public) do |status|
11    # do something here with each individual status in 
      timeline that is also returned
12    puts status.text
13  end
14  
15  # can also pass a block like above to process each 
    individual status object returned in timeline
16  friends_timeline = client.timeline_for(:friends) 
17  
18  # same as above with block if you want
19  friend_timeline = client.timeline_for(:friend, friend)
20  
21  # Retrieve the user object (with all public profile 
    information) for my friend
22  user = Twitter::User.find(friend)
23  
24  # If I don't want to be friends any more I "defriend" the 
    user...
25  user.defriend
26  
27  # Now I realize that was a terrible mistake and "befriend" 
    them...
28  user.befriend
29  
30  # At this point I want to send them a private message to let 
    them know I made a mistake
31  # You can do this in two ways.
32  message = Twitter::Message.create(:client => client, :user 
    => user, 
33    :text => "I didn't really mean to defriend you.  Sorry!")
34  # OR...
35  message = client.message(:post, "I didn't really mean to 
    defriend you.  Sorry!", user)
36  
37  # Now I want to post a new status to my own timeline.
38  # This can be done one of two ways...
39  status = Twitter::Status.create(:client => client, :text => 
    'Sleeping off the beer from last night')
40  # OR...
41  status = client.status(:post, 'Sleeping off the beer from 
    last night')
42  
43  # Now I realize my mother is on twitter and wouldn't like to 
    see me talking about beer,
44  # so assuming she doesn't have IM or SMS alerts we can 
    delete the evidence....
45  client.status(:delete, status)
46  

aws/s3指Amazon Web Service Simple Storage Service
需要两个gem，aws/s3和main
gem install aws/s3
gem install main

 1  #!/bin/env ruby
 2  
 3  require 'rubygems'
 4  require 'main'
 5  require 'aws/s3'
 6  include AWS::S3
 7  
 8  Main {
 9    argument('source_filename') {
10      cast :string
11      description 'source filename to copy to S3'
12    }
13  
14    argument('bucket_name') {
15      cast :string
16      description 'bucket to place the file in on S3'
17    }
18  
19    option('access_key_id') {
20      argument :optional
21      description 'specify the access_key_id manually'
22      default 'put your access key here if you want'
23    }
24  
25    option('secret_access_key') {
26      argument :optional
27      description 'specify the secret key manually'
28      default 'put your secret key here if you want'
29    }
30  
31    def run
32      bucket_name = params['bucket_name'].value
33      source_filename = params['source_filename'].value
34  
35      Base.establish_connection!(
36        :access_key_id     => params['access_key_id'].value,
37        :secret_access_key => 
          params['secret_access_key'].value
38      )
39  
40      begin
41        Bucket.find(bucket_name)
42      rescue
43        puts "Need to make bucket #{bucket_name}.."
44        Bucket.create(bucket_name)
45  
46        # Confirm its existence..
47        Bucket.find(bucket_name)
48      end
49  
50      puts "Got bucket.."
51      puts "Uploading #{File.basename(source_filename)}.."
52      S3Object.store(File.basename(source_filename), 
        open(source_filename), bucket_name)
53      puts "Stored!"
54  
55      exit_success!
56    end
57  }

// 在config/environment.rb中添加

1  ActionView::Base.field_error_proc = Proc.new {|html_tag, 
   instance| 
2  %(<span class="field-with-errors">#{html_tag}</span>)}

// 代码描述

1  posts = Post.find(:all)
2  p_ids = posts.collect{|p| p.id}.join(',')
3  replies = Reply.find(:all, {:conditions => ["post_id in 
   (#{p_ids})"]})

要在图形上显示中文，需要中文字体，比如sim
* hei.ttf

 1  require 'gruff'
 2  
 3  g = Gruff::Line.new
 4  g.font = "#{RAILS_ROOT}/public/fonts/simhei.ttf" 
 5  g.title = "中文" 
 6  
 7  g.data("苹果", [1, 2, 3, 4, 4, 3])
 8  g.data("橘子", [4, 8, 7, 9, 8, 9])
 9  g.data("西瓜", [2, 3, 1, 5, 6, 8])
10  g.data("桃子", [9, 9, 10, 8, 7, 9])
11  
12  g.labels = {0 => '2003', 2 => '2004', 4 => '2005'}
13  
14  g.write('my_fruity_graph.png')

1  @start_at = params[:event]['start_at(1i)'] + "-" + 
   params[:event]['start_at(2i)'] + "-" + 
   params[:event]['start_at(3i)'] + " " + 
   params[:event]['start_at(4i)'] + ":" + 
   params[:event]['start_at(5i)'] + ":00"

// 朋友关系Friend的model

1  class Friend < User
2    has_and_belongs_to_many :users, :join_table => "friends", 
     :foreign_key => "to_id", :association_foreign_key => 
     "from_id"
3  end

1  CREATE TABLE `friends` (
2  `from_id` int( 11 ) NOT NULL default '0',
3  `to_id` int( 11 ) NOT NULL default '0',
4  PRIMARY KEY ( `from_id` , `to_id` ) ,
5  KEY `fk_fu_from` ( `from_id` ) ,
6  KEY `fk_fu_to` ( `to_id` ) 
7  ) ENGINE = InnoDB DEFAULT CHARSET = utf8;

Book和Page是1:n的关系
book.rb

1  class Book < ActiveRecord::Base
2    has_many :pages
3  end

 1  class Page < ActiveRecord::Base
 2    belongs_to :book
 3    
 4    validates_presence_of :page_id
 5  
 6    # 验证父对象是否有效
 7    validate do |page|
 8     if page.blank?
 9       unless page.book(true)
10         errors.add(:page_id, "must be a valid Book id")
11       end
12     end
13    end
14  
15  end

application.rb中的代码

1  class ApplicationController < ActionController::Base
2   
3    def hello(name)
4     "Hello #{name}"
5    end
6  
7  end

1  class UserController < ApplicationController
2  
3    before_filter :only => :index do |u| 
4      u.hello('Master')
5    end
6  
7  end

 1  class Vector   
 2    attr_reader :x , :y, :mod  
 3    attr_writer :x, :y  
 4    #初始化   
 5    def initialize(x,y)   
 6      @x = x   
 7      @y = y   
 8      @mod = (x**2 + y**2) ** 0.5   
 9    end  
10    #加   
11    def +(vector)   
12      if vector.class != Vector   
13        puts  "#{vector}不是一个向量！"  
14      else  
15        @x += vector.x   
16        @y += vector.y   
17        puts "(#@x,#@y)"  
18      end  
19    end  
20    #减   
21    def -(vector)   
22      if vector.class != Vector   
23        puts  "#{vector}不是一个向量！"  
24      else  
25        @x -= vector.x   
26        @y -= vector.y   
27        puts "(#@x,#@y)"  
28      end  
29    end  
30    #是否平行   
31    def parallel?(vector)   
32      if vector.class != Vector   
33        puts  "#{vector}不是一个向量！"  
34      else    
35        puts((vector.x / @x) == (vector.y / @y))    
36      end  
37    end  
38    #与实数的积   
39    def multiply(number)   
40      if (number.class == Fixnum) or (number.class == Bignum) 
        or (number.class == Float)   
41       @x *= number   
42       @y *= number   
43        puts "(#@x,#@y)"  
44      else  
45        puts "#{number}不是一个数字！"  
46      end  
47    end  
48    #数量积   
49    def innerproduct(vector)   
50      if vector.class != Vector   
51        puts  "#{vector}不是一个向量！"  
52      else    
53        puts @x * vector.x + @y * vector.y   
54      end  
55    end  
56    #是否垂直   
57    def vertical?(vector)   
58      if vector.class != Vector   
59        puts  "#{vector}不是一个向量！"  
60      else    
61        puts((@x * vector.x + @y * vector.y) == 0)   
62      end  
63    end  
64    #夹角   
65    def inclination(vector)   
66      if vector.class != Vector   
67        puts  "#{vector}不是一个向量！"  
68      else    
69        puts Math.acos((@x * vector.x + @y * vector.y) / (@mod 
          * vector.mod))    
70      end  
71    end  
72    #平移   
73    def translate(vector)   
74      if vector.class != Vector   
75        puts  "#{vector}不是一个向量！"  
76      else  
77        @x += vector.x   
78        @y += vector.y   
79        puts "(#@x,#@y)"  
80      end  
81    end  
82  end