lazy_observers

Make Activerecord Observers not load observed models -> faster/safer environment boot.

• faster tests + console
• able to boot environment without/with empty/with old database

Recommended: turn your observers into modules

module CachingObserver
  def self.included(base)
    this = self
    base.after_save { |record| this.do_something(record); true }
  end

  def self.do_something(record)
     ... do something ...
  end
end

Install

gem install lazy_observers

Usage

class FooObserver < ActiveRecord::Observer
  lazy_observe "User", "Foo::Bar"

  ...
end

Extend models from gems after they are loaded

LazyObservers.on_load("Arturo::Feature") do |klass|
  klass.class_eval do
    ... funky hacks ...
  end
end

Catch models that are loaded in application startup.

LazyObservers.debug_active_record_loading

script/console or rails c

Verify you did not misspell

Loads all classes registered via observers, to make sure you did not misspell
(negates the effect of lazyness, so only use for debugging)

LazyObservers.check_classes

TIPS

• .on_load is called before all methods are defined on the baseclass, so they might not be defined
• do not use observe and lazy_observe in the same observer (and if you have to, use observe after lay_observe)
• do not use Model classes with class-methods of the observer e.g. class FooObserver; Foo.something{}; def after_update; end; end

Author

Michael Grosser
[e-mail]
License: MIT