Module: ROM::Notifications

Extended by:

Publisher

Included in:

Configuration

Defined in:

lib/rom/support/notifications.rb

Overview

Notification subsystem

This is an abstract event bus that implements a simple pub/sub protocol. The Notifications module is used in the setup process to decouple different modules from each other.

Examples:

class Setup
  extend ROM::Notifications

  register_event('setup.before_setup')
  register_event('setup.after_setup')

  def initialize
    @bus = Notifications.event_bus(:setup)
  end

  def setup
    @bus.trigger('setup.before_setup', at: Time.now)
    # ...
    @bus.trigger('setup.after_setup', at: Time.now)
  end
end

class Plugin
  extend ROM::Notifications::Listener

  subscribe('setup.after_setup') do |event|
    puts "Loaded at #{event.at.iso8601}"
  end
end

Defined Under Namespace

Modules: Listener, Publisher Classes: Event, EventBus

Constant Summary

LISTENERS_HASH =

Hash.new { |h, k| h[k] = [] }

Class Method Summary

• .event_bus(id) ⇒ Notifications::EventBus

  Build an event bus.

• .events ⇒ Object private
• .listeners ⇒ Object private

Instance Method Summary

• #register_event(id, info = EMPTY_HASH) ⇒ Object

  Register an event.

Methods included from Publisher

subscribe, trigger

Class Method Details

.event_bus(id) ⇒ Notifications::EventBus

Build an event bus

Parameters:

• id (Symbol) —

  Bus key

Returns:

• (Notifications::EventBus) —

  A new bus

# File 'lib/rom/support/notifications.rb', line 168

def self.event_bus(id)
  EventBus.new(id, events: events.dup, listeners: listeners.dup)
end

.events ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

# File 'lib/rom/support/notifications.rb', line 153

def self.events
  @__events__ ||= {}
end

.listeners ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

# File 'lib/rom/support/notifications.rb', line 158

def self.listeners
  @__listeners__ ||= LISTENERS_HASH.dup
end

Instance Method Details

#register_event(id, info = EMPTY_HASH) ⇒ Object

Register an event

Parameters:

• id (String) —

  A unique event key

• info (Hash) (defaults to: EMPTY_HASH)

# File 'lib/rom/support/notifications.rb', line 148

def register_event(id, info = EMPTY_HASH)
  Notifications.events[id] = Event.new(id, info)
end