Waffle

An abstract flow publisher and subscriber.

It supports the following transports:

• RabbitMQ
• Redis

Configuration

Insert in your Gemfile:

gem 'bunny' # for RabbitMQ transport
gem 'hiredis' # for Redis transport
gem 'redis', require: ['redis', 'redis/connection/hiredis'] # for Redis transport
gem 'waffle', :gem => 'git://github.com/undr/waffle.git'

Warning! Gem 'waffle' must follow gems 'bunny' and 'redis' in Gemfile.

Create config file:

production:
  transport: rabbitmq
  encoder: marshal
  url: amqp://anyhost.com:5678

and load it:

Waffle.configure(:path => 'config/waffle.yml')

You also can configure Waffle programmatically:

Waffle.configure({
  :transport => 'redis',
  :url => 'redis://localhost:6379/0',
  :encoder => 'json'
})

or:

Waffle.configure do
  default do |config|
    config.transport = 'redis'
    config.url = 'redis://localhost:6379/0'
    config.encoder = 'json'
  end
end

Multitransport config

You can use many transports for organising your messaging system. Just add to config file queues section:

production:
  transport: rabbitmq
  encoder: marshal
  url: amqp://anyhost.com:5678
  queues:
    redis_name:
      transport: redis
      encoder: json
      url: redis://localhost:6379/0

or programmatically:

Waffle.configure({
  :transport => 'redis',
  :url => 'redis://localhost:6379/0',
  :encoder => 'json',
  :queues => {
    :redis_name => {
      :transport => 'redis',
      :url => 'redis://localhost:6380/0',
      :encoder => 'json',
    }
  }
})

# or

Waffle.configure do
  default do |config|
    config.transport = 'redis'
    config.url = 'redis://localhost:6379/0'
    config.encoder = 'json'
  end

  queue(:redis_name) do |config|
    config.transport = 'redis'
    config.url = 'redis://localhost:6380/0'
    config.encoder = 'json'
  end
end

Usage

Event

When you want to performan event, just insert this code in place, where it must occur:

Waffle::Event.occurred 'message'

You can attach meta data to event like this:

Waffle::Event.occurred {'user_id' => 13, 'user_name' => 'Joshua'}, :event_name => 'index_page_load'

or like this:

Waffle::Event.occurred 'bingo!', :event_name => 'index_page_load'

or:

Waffle::Event.occurred 'message', :event_name => 'index_page_load', :queue => :experimental_queue

Pub/Sub

Waffle.publish('event.name', message_hash_or_string)

Waffle.subscribe('event.name') do |message_type, message_hash_or_string|
  pp message_type
  pp message_hash_or_string
end

Multitransport usage

Waffle.queue(:redis_name).publish('event.name', message_hash_or_string)

Waffle.queue(:redis_name).subscribe('event.name') do |message_type, message_hash_or_string|
  pp message_type
  pp message_hash_or_string
end

Reconnect

Don't care about any reconnects when transport server is down. Waffle just waits for server ready and reconnects automatically.