Question

I’m successfully using ActiveRecord 3.2.9 in a Sinatra 1.3.3 application. I would like to be able to use ActiveRecord::Observer classes, but I’m not sure how to activate them.

The ActiveRecord::Observer docs are specific to Rails about this particular bit:

In order to activate an observer, list it in the config.active_record.observers configuration setting in your config/application.rb file.

Of course, I don’t have a “config” object on which to set this setting. Any ideas?

EDIT

I tried activating the observers like so:

ActiveRecord::Base.observers = [ :thermometer_reading_observer ]

This does something, in that they are correctly set, but they still don’t do anything:

[4] pry(main)> ActiveRecord::Base.observers
=> [:thermometer_reading_observer]

Answer 1

Got it figured out from perusing the ActiveRecord source here:

To activate an observer outside of Rails, do the following (with my Observer as an example):

ActiveRecord::Base.add_observer ThermometerReadingObserver.instance

Hopefully this helps someone!