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When Twitter was still in its early stages, you could track certain search terms in near-realtime via Jabber. It was quite popular and its performance degraded over time as more users signed up and began posting updates. Eventually, Twitter killed the jabber bot altogether. Many users have asked when it will return.

Well, it hasn't returned, but you can build your own replacement with ruby, a jabber account, and a few gems. While it won't do everything that the original jabber bot did, you can still track tweets mentioning certain terms very quickly.

Here's how to get started:

First, install the tweetstream and xmpp4r-simple gems:

gem install tweetstream xmpp4r-simple

Next, you'll need a jabber account. You'll probably want to make one for the exclusive use of your jabber bot. I chose to make up a quick account at ChatMask for mine.

The last step is to drop a copy of this script on your server:

#!/usr/bin/ruby
require 'rubygems'
require 'tweetstream/client'
require 'tweetstream/hash'
require 'tweetstream/status'
require 'tweetstream/user'
require 'tweetstream/daemon'
require 'xmpp4r-simple'
 
jabber = Jabber::Simple.new('jabberbot@yourjabberserver.com','jabberpassword')
 
tweets = TweetStream::Client.new(twitterusername,twitterpassword)
 
tweets.track('celtics','lakers','finals','nba') do |status, client|
  imtext = "#{status.user.screen_name}: #{status.text} \r\n"
  imtext += "[http://twitter.com/#{status.user.screen_name}/status/#{status.id}]"
  jabber.deliver("yourjabberusername@yourjabberserver.com",imtext)
end
 
jabber.disconnect

You'll want to be sure to fill in the following:

• your jabber bot's username and password
• the username and password for the twitter account that will monitor the stream
• the search terms you want to track
• the destination jabber account where the messages should be sent

Ensure that your jabber account has authorized the jabber bot's account so that you'll actually receive the messages. Also, Twitter is very strict with their streaming API tracking terms. It's a good idea to review their entire Streaming API documentation to ensure that you're not going to end up having your account temporarily or permanently blacklisted.

Once everything is ready to go, you can just run the script within GNU screen or via nohup. There's still a bit more error checking to do around jabber reconnections, but the script has run non-stop for well over two weeks at a time without a failure.

©2010 Racker Hacker. All Rights Reserved.

.

It certainly shouldn't be difficult, but I always have a tough time with OAuth. Twitter is dropping support for basic authentication on June 30th, 2010. I have some automated Twitter bots that need an upgrade, so I've been working on a quick solution to generate tokens for my scripts.

I formulated a pretty simple script using John Nunemaker's twitter gem that will get it done manually for any scripts you have that read from or update Twitter:

#!/usr/bin/ruby
require 'rubygems'
require 'twitter'
 
# These credentials are specific to your *application* and not your *user*
# Get these credentials from Twitter directly: http://twitter.com/apps
application_token = '[this should be the shorter one]'
application_secret = '[this should be the longer one]'
 
oauth = Twitter::OAuth.new(application_token,application_secret)
 
request_token = oauth.request_token.token
request_secret = oauth.request_token.secret
puts "Request token => #{request_token}"
puts "Request secret => #{request_secret}"
puts "Authentication URL => #{oauth.request_token.authorize_url}"
 
print "Provide the PIN that Twitter gave you here: "
pin = gets.chomp
 
oauth.authorize_from_request(request_token,request_secret,pin)
access_token = oauth.access_token.token
access_secret = oauth.access_token.secret
puts "Access token => #{oauth.access_token.token}"
puts "Access secret => #{oauth.access_token.secret}"
 
oauth.authorize_from_access(access_token, access_secret)
twitter = Twitter::Base.new(oauth)
puts twitter.friends_timeline(:count => 1)

When you run the script, it will give you a request token, request secret and a URL to visit. When you access the URL, you'll be given a PIN. Type the PIN into the prompt and you'll get your access token and secret. This is what you can use to continue authenticating with Twitter, so be sure to save the access token and secret.

From then on, you should be able to login with a script like this:

#!/usr/bin/ruby
require 'rubygems'
require 'twitter'
 
application_token = '[this should be the shorter one]'
application_secret = '[this should be the longer one]'
 
oauth = Twitter::OAuth.new(application_token,application_secret)
 
oauth.authorize_from_access(access_token, access_secret)
twitter = Twitter::Base.new(oauth)
puts twitter.friends_timeline(:count => 1)

I hope this helps!

©2010 Racker Hacker. All Rights Reserved.

.

Делаю очередной проект на Ruby on Rails. Как обычно, в миграциях понадобились foreign keys на уровне БД. Окинул взглядом все плагины, которые смог найти в google и на github.com. Ни один из них не умеет делать FK, используя ActiveRecord::ConnectionAdapters::Table#references и ActiveRecord::ConnectionAdapters::TableDefinition#references.

Поэтому сел и написал свой плагин: active_record_foreign_keys.

Установка:

Rails::Initializer.run do |config|
  ...
  config.gem "active_record_foreign_keys", :source => "http://gemcutter.org"
  ...
end

$ rake gems:install

Использование:

def self.up
  # create reference table
  create_table :users do |t|
  end
  # create referencing table
  create_table :a_examples do |t|
    t.references :user, :foreign_key => true
  end
  # or
  create_table :b_examples do |t|
    t.references :user, :foreign_key => {  n_update => :cascade,  n_delete => :restrict }
  end
  # or
  create_table :c_examples do |t|
  end
  add_foreign_key :c_examples, :user_id, :users, :id,  n_update => :no_action,  n_delete => :set_null
  # or change existing table
  change_table :d_examples do |t|
    t.references :user, :foreign_key => true
  end
end
def self.down
  # remove constraint
  remove_foreign_key :examples, :user_id, :users, :id
end

Плагин тестировался только под PostgreSQL, но по идее должен работать и под MySQL, и под Sqlite.

Прежде всего необходимо установить сам ruby

yum install ruby ruby-devel ruby-libs ruby-irb ruby-rdoc ruby-mysql rubygems

Так же понадобится компилятор и заголовки ImageMagick

yum install gcc make ImageMagick-devel

Для корректной работы не помешает обновить gem

gem update --system
gem update

Для компиляции rmagick потребуются шрифты, для установки которых потребуется rpmbuild и cabextract

yum install rpm-build cabextract

В /usr/src/redhat/BUILD/msttcorefonts/ необходимо загрузить шрифты, которые доступны по ссылке http://sourceforge.net/project/showfiles.php?group_id=34153&release_id=105355 (нужно загрузить непосредственно .exe-файлы со шрифтами).

Загрузите в папку /usr/src/redhat/SPECS файл http://corefonts.sourceforge.net/msttcorefonts-2.0-1.spec и запустите

rpmbuild -ba msttcorefonts-2.0-1.spec

Теперь можно установить шрифты

rpm -Uhv /usr/src/redhat/RPMS/noarch/msttcorefonts-2.0-1.noarch.rpm

Для установки rmagick, потребуется сделать symlink

ln -s /usr/share/fonts/msttcorefonts /usr/share/fonts/default/TrueType

А теперь можно смело устанавливать rmagick

gem install rmagick -v 1.15.17

Иногда нужно использовать валидацию для введенных через форму данных, но при этом эти данные никакого отношения к базе данных не имеют. Например, данные формы обратной связи.

Можно сэмулировать стандартную модель использую такой базовый класс-заглушку:

module ActiveRecord
  class Model
    def id; nil; end
    def new_record?; true; end
    def save; nil; end
    def save!; nil; end
    class << self
      def human_name(options = {})
        defaults = self_and_descendants_from_active_record.map do |klass|
          :"#{klass.name.underscore}"
        end
        defaults << self.name.humanize
        I18n.translate(defaults.shift, {:scope => [:activerecord, :models], :count => 1, :default => defaults}.merge(options))
      end
      def human_attribute_name(attribute_key_name, options = {})
        defaults = self_and_descendants_from_active_record.map do |klass|
          :"#{klass.name.underscore}.#{attribute_key_name}"
        end
        defaults << options[:default] if options[:default]
        defaults.flatten!
        defaults << attribute_key_name.humanize
        options[:count] ||= 1
        I18n.translate(defaults.shift, options.merge(:default => defaults, :scope => [:activerecord, :attributes]))
      end
      def self_and_descendants_from_active_record
        klass = self
        classes = [klass]
        while klass != klass.base_class
          classes << klass = klass.superclass
        end
        classes
      rescue
        [self]
      end
    end
    def initialize(params = nil)
      unless params.nil?
        params.each do |k,v|
          self.send("#{k}=", v)
        end
      end
    end
    include ActiveRecord::Validations
  end
end

Класс псевдомодели для формы обратной связи будет выглядить так:

class Message < ActiveRecord::Model
  attr_accessor :name
  attr_accessor :email
  attr_accessor :subject
  attr_accessor :body
  validates_presence_of :name
  validates_length_of :name, :within => 2..16, :allow_blank => true
  validates_presence_of :email
  validates_length_of :email, :within => 6..32, :allow_blank => true
  validates_format_of :email, :with => Authlogic::Regex.email, :allow_blank => true
  validates_presence_of :subject
  validates_length_of :subject, :within => 2..32, :allow_blank => true
  validates_presence_of :body
  validates_length_of :body, :within => 5..4096, :allow_blank => true
  def send_to(recipient)
    # send message to recipient
  end
end

Такую псевдомодель можно использовать в шаблонах с хелпером form_for как обычную. Интернационализация сообщений об ошибках работает так же, как если бы это была обычная модель ActiveRecord::Base.

Пример использования:

class ContactsController < ApplicationController
  def new
    @message = Message.new
  end
  def create
    @message = Message.new(params[:message])
    if @message.valid?
      @message.send_to(configatron.contacts.email)
      flash[:notice] = "Сообщение успешно отправлено"
      redirect_to new_contact_path
    else
      render :action => "new"
    end
  end
end