Ruby EventEmitter

Ruby port of EventEmitter from Node.js

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INSTALL:

% gem install event_emitter

REQUIREMENTS:

  • Ruby 1.8.7+
  • Ruby 1.9.2+
  • JRuby 1.6.7+

SYNOPSIS:

setup

load rubygem

require "rubygems"
require "event_emitter"

include EventEmitter in class definition

class User
  include EventEmitter
  attr_accessor :name
end

on/emit

regist event listener

user = User.new
user.name = "shokai"
user.on :go do |data|
  puts "#{name} go to #{data[:place]}"
end

call event

user.emit :go, {:place => "mountain"}
# => "shokai go to mountain"

once

regist event using "once"

user.once :eat do |what, where|
  puts "#{name} ->  eat #{what} at #{where}"
end

call only once

user.emit :eat, "BEEF", "zanmai" # =>  "shokai -> eat BEEF at zanmai"
user.emit :eat, "Ramen", "marutomo"  # => do not call.

remove listener

remove event listener by name 
user.remove_listener :go
remove event listener by event_id 
event_id = user.on :go do |data|
  puts "#{name} go to #{data[:place]}"
end
user.remove_listener event_id

Instance-Specific Method

apply as instance-specific method

class User
end

shokai = User.new
ymrl = User.new
EventEmitter.apply shokai ## set Instance-specific Method

shokai.on :go do |data|
  puts "go to #{data[:place]}"
end

shokai.emit :go, :place => "chiba city"
# => "go to chiba city"

ymrl.on :go do |data|  # => raise "undefined-method Error"
  puts "go to #{data[:place]}"
end

Class Method

apply as class method

class DB
  def self.connect
    self.emit :connect, "db_connected"
  end
end

EventEmitter.apply DB ## set Class Method

DB.on :connect do |status|
  puts status
end

DB.connect # => "db_connected"

More Samples